a guide to environmental analysis for energy planners

STOCKHOLMENVIRONMENTINSTITUTES E I

Boston Center, Tellus Institute11 Arlington Street, Boston, MA, 02116 USA

A Guide to Environmental AnalysisFor Energy Planners

Prepared By:Michael Lazarus and David Von Hippel

withDavid Hill and Robert Margolis

Stockholm Environment Institute--Boston

December 1995

Table of Contents

1. INTRODUCTION............................................................................................................................................ 1

1.1 KEY ISSUES AND THE DESIGN OF THE GUIDE................................................................................................... 21.2 CHALLENGES AND CONCERNS IN QUANTITATIVE ANALYSIS ............................................................................ 7

2. MAJOR ENVIRONMENTAL PROBLEMS ASSOCIATED WITH ENERGY ACTIVITIES.................. 11

2.1 INTRODUCTION ........................................................................................................................................... 112.2 GLOBAL ISSUES........................................................................................................................................... 132.3 REGIONAL ISSUES........................................................................................................................................ 232.4 LOCAL ISSUES ............................................................................................................................................. 34

3. DESCRIPTION OF MAJOR ENVIRONMENTAL EFFECTS CATEGORIES......................................... 43

3.1 INTRODUCTION ........................................................................................................................................... 433.2 AIR EMISSIONS ........................................................................................................................................... 483.3 WATER EFFLUENTS ..................................................................................................................................... 613.4 SOLID WASTES ........................................................................................................................................... 643.5 OCCUPATIONAL HEALTH AND SAFETY EFFECTS............................................................................................ 653.6 OTHER EFFECTS.......................................................................................................................................... 65

4. ENVIRONMENTAL LOADING DATA: SOURCES, ESTIMATION, AND UNCERTAINTY ................ 67

4.1 INTRODUCTION ........................................................................................................................................... 674.2 EMISSION FACTORS: WHAT THEY ARE AND WHERE THEY COME FROM............................................................ 674.3 THE CAUSE-AND-EFFECT RELATIONSHIP IN EMISSION FACTORS .................................................................... 714.4 DETERMINING THE APPROPRIATE UNITS FOR EMISSION FACTORS .................................................................. 724.5 MEASUREMENT AND ESTIMATION OF EMISSION AND IMPACT FACTORS .......................................................... 754.6 DETERMINING THE APPROPRIATE EMISSION FACTORS TO USE ......................................................................... 834.7 UNCERTAINTY, ERRORS AND LIMITS OF APPLICABILITY................................................................................ 874.8 CATEGORIES OF EMISSION FACTORS PARTICULARLY SENSITIVE TO LOCAL CONDITIONS.................................... 884.9 MAJOR SOURCES AND TYPES OF EMISSION FACTORS DATA.............................................................................. 92

5. DEVELOPING LOADINGS INVENTORIES AND PROJECTIONS FOR THE ENERGY SECTOR..... 94

5.1 INTRODUCTION ........................................................................................................................................... 955.2 LEAP AND EDB......................................................................................................................................... 975.3 STEP-BY-STEP GUIDE TO PERFORMING ENERGY AND ENVIRONMENTAL ANALYSIS......................................... 985.4 A CASE-STUDY APPLICATION OF LEAP AND EDB: COSTA RICA .................................................................108

6. EXTENDING THE ANALYSIS FROM EMISSIONS TO DAMAGE .......................................................117

6.1 INTRODUCTION ..........................................................................................................................................1176.2 STEPS OF ANALYSIS FROM EMISSION TO IMPACTS ........................................................................................1186.3 TYPES OF MODELS AND APPROACHES FOR IMPACT ASSESSMENT ..................................................................1226.4 SOME SIMPLIFIED INDICES AND SELECTED STANDARDS ...............................................................................1286.5 SUGGESTED RESOURCES FOR ENVIRONMENTAL MODELING..........................................................................130

7. REFERENCES..............................................................................................................................................131

APPENDIX A: ANNOTATED LIST OF LITERATURE REFERENCES USED IN COMPILING THEENVIRONMENTAL DATABASE (EDB.........................................................................................................139

APPENDIX B: SUMMARY OF TABLE OF CONTENTS FROM GUIDELINE ON AIR QUALITYMODELS (USEPA)...........................................................................................................................................163

ACKNOWLEDGMENTS

The authors the Swedish International Development Agency for supporting the development of this Guide.We would also like to thank Gordon Mackenzie of the UNEP Collaborating Centre for his comments andencouragement, as well as Charlie Heaps and Evan Hansen who contributed to the development of EDB,and provided materials for this manual. The concept of this guide was inspired by requests from energyplanners and analysts -- particularly input from Bashiri Mrindoko of the Tanzanian Ministry of Energy andMinerals -- for a reference guide and background material on a growing area of their interest andresponsibility.

STOCKHOLM ENVIRONMENT INSTITUTE--BOSTONTellus Institute11 Arlington StreetBoston, Massachusetts, 02116-3411 USATelephone: 617-266-8090Telefax: 617-266-8303Email: [email protected]: http://www.tellus.org

Introduction 1

1. Introduction

The incorporation of environmental considerations has become an important new area for energyplanners. Energy use and production can be major sources of serious environmental impacts. Theseimpacts, in turn, can threaten the overall social and economic development objectives that energy use isthought to promote. Examples of such dilemmas abound. At the regional and global levels, fossil fuelconsumption leads to acid rain and, most likely, to global warming; both phenomena could disrupt naturalsystems and economic productivity. At the local level, continued reliance on traditional biomass fuels, inmany developing countries, can place added stress on woodlands and farmlands, further contributing to soilerosion and habitat loss, and can lead to high levels of indoor air pollution.

In many countries, success in resolving energy-environmental questions is critical. Rapid changesare occurring in both rural and urban areas that will affect generations to come. Land clearing foragriculture and energy have local impacts and potential global climate impacts. The rapid expansion ofurban areas is changing energy use patterns, as more people enter the cash economy and commercial fuels(electricity, petroleum products, etc.) become options for displacing their use of traditional fuel use (wood,charcoal, crop residues, etc.). The demand for energy services such as space cooling and transportationtends to increase very rapidly with industrialization and rising incomes. Such so-called energy transitions,when they occur, will have significant effects on air, water, and land, locally and globally. At present,there are great opportunities for directing energy use and production patterns toward those that, recognizingenvironmental externalities, will help to minimize long-term economic and social costs.

To this end, many countries are currently building energy and environmental planning capacity.These institutions are generally relatively new and in need of important resources: training, experience, anduseful methods adapted to local conditions. Environmental analyses have tended to be few, and preparedon an ad-hoc basis as needed for project approval -- often at the behest of donor agencies. The lack oflocal studies and data can impose serious constraints on planning, as can the near-term and growth-orientedfocus of developing economies. Applicable planning methods must consider these constraints.

Computerized decision support systems can provide useful assistance in the analysis of availableinformation, the projection of future conditions, and the evaluation of alternative scenarios. The use ofthese systems can help countries advance toward the goal of implementing useful analytic methods forenergy and environment planning. One such tool is the Long-Range Energy Alternatives planning system(LEAP), used by energy ministries and researchers in over 30 countries worldwide. With support from theUnited Nations Environment Programme (UNEP) and the Swedish International Development Agency(SIDA), SEI-B expanded LEAP to enable more integrated energy-environmental analysis. The majorproduct of this effort, the Environmental Data Base (EDB), contains an extensive collection of emissionand direct impact coefficients for a wide range of energy producing, consuming, and conversion processesand technologies. EDB can also incorporate local data, if available, on emissions and direct impacts ofenergy processes. The analyst can then use EDB data with LEAP to estimate the comparativeenvironmental loadings associated with a range of energy scenarios.

The expansion of energy scenario analysis to incorporate environmental considerations raises anumber of important questions and challenges, ranging from the choice of which factors to include in theanalysis to the evaluation of results across scenarios and categories of environmental impact. At the outset,it is crucial to emphasize that integrated energy-environmental analysis is still a relatively new and evolvingfield, particularly when compared to energy analysis alone. Most LEAP users, for instance -- a groupcomprised largely of energy planners, engineers, and economists -- are familiar with the challenges posed

2 A Guide to Environmental Analysis For Energy Planners

by limited data and understanding of the factors and relationships (price, income, saturation, politics, andothers) affecting energy use. On the model development side, assembling a set of estimates andassumptions regarding physical and direct cost impacts of energy technologies and policies may takeconsiderable effort, but the methods are relatively straightforward. On the model output side, economicindicators such cost-benefit ratios and oil import bills, and physical indicators such as energy balancesheets and cumulative resource depletion are well defined. In contrast, when we turn to environmental"inputs" and "outputs", we are confronted with a far more complex web of relationships -- from local toglobal scales and from human health to ecological issues -- and far less in terms of standard methods andprecise information.

This guide provides a path that leads, one might say, both into and out of the woods. We presentsome of the complexities and uncertainties of energy-environment relationships, and follow withinformation and guidance for conducting integrated analyses. Together, LEAP and EDB provide arelatively simple and flexible quantitative framework for approaching many of the important environmentaland economic consequences of energy strategies. While this flexibility enables the planner to construct amodel and use data applicable to local concerns, it also requires the background and knowledge to do so inan appropriate manner. Furthermore, the quantitative nature of the analysis conducted with such a modelshould not diminish the importance of issues that are non-quantifiable or consideration of topics for whichdata or relationships are highly uncertain.

The art of judicious simplification becomes essential to avoiding the potentially overwhelmingdiversity of approaches and issues that may be of concern to a planning agency. Each environmentalconcern, from the impacts of cooking fuels and practices on human health to the ecological consequences ofexploiting biomass, hydro, or surface coal resources, may appear worthy of detailed and localized study.These studies should be initiated where appropriate, but the absence of such studies should not preclude theinitial incorporation of environmental concerns in energy planning.

1.1 Key Issues and the Design of the Guide

Given these challenges and concerns, we initially conceived this guide as a companion manual toassist users of LEAP and EDB. Many users requested additional assistance in incorporating environmentalparameters into their energy analyses. LEAP/EDB users are typically energy planners with limited, if any,previous exposure to environmental science, and several have asked for more background on the nature ofvarious pollutants, from their sources to their pathways of impact. In response, Section 2 provides ageneral overview of the major global, regional, and local environment issues related to energy use, andSection 3 describes the major pollutant and impact categories as used in EDB.

In conducting an integrated energy-environment analysis, one must establish several sets ofboundaries. One of these sets defines which environmental concerns (indoor air quality, land degradation,global climate change, etc.) and related parameters (toxic hydrocarbon emissions, cleared land, greenhousegas emissions, etc.) to investigate and consider. Such a list is ideally based upon a thorough assessment ofnational and local environmental concerns and priorities. Comparative environmental analysis can play animportant role in determining these priorities, and in turn, can help to orient the emphasis of integratedenergy-environmental analyses1. For example, a number of developing country energy studies andprograms of the 1970s and 1980s were based on the notion that deforestation and desertification were

1 Comparative environmental assessment seeks to evaluate the relative risks posed by the multitude of environmentalproblems using a combination of risk analysis and expert judgment. See Unfinished Business: A Comparative Assessment ofEnvironmental Problems: Overview Report, U.S. Environmental Protection Agency, Office of Policy Analysis, February 1987.

Introduction 3

rapidly expanding largely as the result of the demand for woodfuels. In a number of cases, however, othercausal factors -- land clearing for agriculture, timber exports, and other non-energy factors -- have been asimportant, or more so, in causing these problems. Comparative risk analyses or other more simpler studies,such as national reports to the 1992 Rio UNCED Conference, or National Environmental Action Plans, canprovide an important starting point for outlining the important energy-environment issues that should beemphasized2.

It is also necessary to define a set of boundaries around those effects of the energy system that willbe considered. For instance, a new coal-fired electric facility will require materials and energy for plantconstruction, will require disposal of ashes and/or scrubber wastes during plant operation, and will requiretransport of coal from the mine. Disposal of waste will involve additional transportation to and from thedisposal sites. One can go further down the chain of required events and measure, for example, the impactsof manufacturing the additional vehicles required for waste disposal. Obviously, these sorts of analyses --often referred to as life cycle, full fuel cycle, or fuel chain analyses -- can go on ad infinitum (that is,indefinitely). To deal with similar types of interlinkages in the full economy, economists have developedinput-output models. While there are no similarly well-developed methods or models for full fuel cycleanalysis, many attempts have been made to define the most important aspects of individual fuel cycles --for example, alcohol from biomass, or electricity from coal -- that should be considered. LEAP itselfembodies a fuel cycle approach, and has recently been expanded to enable straightforward fuel cycleenvironmental comparisons as part of a UNEP-sponsored project.

In principle, when evaluating fuel choices such as gasoline versus ethanol for vehicletransportation, it is important to consider the primary effects of each major element of the fuel chain, asillustrated in Figure 1.1 below for gasoline. Some “upstream” fuel cycle impacts may occur outside theregion of concern. For instance, oil may be imported and the impacts of oil production thus do not occurlocally. It is then up to existing environmental laws or to the analyst’s judgment as to whether theseimpacts should be considered. Secondary impacts, such as the emissions from production of electricity orfrom the manufacture of steel used at the refinery, vary significantly depending on fuel and technologyoptions considered, but are generally much less important -- and much more difficult to quantify -- than theprimary impacts3.

Section 4 deals with issues related to the development and use of pollutant loading factors (seeTable 1.3 for a definition of this term), and in particular, with the origins of the over 2000 coefficients forair, water, and solid waste emissions, and land use and direct health and safety impacts found in theEnvironmental Data Base (EDB). Air pollutant emission factors, the most commonly reported and perhapsmost important of the energy-related loading factors, are developed from laboratory and field tests underconditions (combustion technologies, ambient conditions, etc.) that may differ significantly from thoseunder study. Very few of the available and published emission factors are based on measurements done indeveloping countries. Most factors are derived from a relatively limited number of studies to date, mostbased on measurements in and for OECD countries, most notably the US, under the ambient conditions(temperature, humidity, etc.), technologies, and operational practices that prevailed where themeasurements were made. In fact, a large number of the published emission factors for fossil fuelcombustion can be traced to a handful of U.S. studies done in the 1980s. We discuss the origins of the

2 Several African countries have prepared National Environmental Action Plans, a concept initiated by the World Bank, foridentifying and prioritizing key environmental issues, focusing on their underlying causes, and developing a plan for addressingthem. See Falloux, F., Talbot, L., Larson, J. “Progress and Next Steps for National Environmental Action Plans in Africa”,World Bank Africa Technical Department, June 1991.3 For more information on fuel cycle analyses, see DeLuchi, 1991.


emission factor data found in EDB, provide some guidance for their use, and suggest where to seekadditional data -- or perform more detailed analysis -- if needed. Appendix A contains an annotatedbibliography of the over 70 references used to develop EDB data.

Table 1.1:Example of Possible Environmental Impacts for the Gasoline Fuel Cycle

Activity Possible Environmental Concern

Locate oil deposit (road building in pristine areas) êDrill oil well (construction, land use, accidents) êExtract crude oil (accidents, spills, gas flaring) êTransport crude oil to refinery (accidents, spills) êRefine oil into gasoline (air emissions, solid and hazardous wastes) êTransport gasoline to filling station (accidents, spills) êFill cars with fuel (leakage from storage, evaporative emissions) êOperate vehicle (evaporative and combustion emissions)

In general, estimates for some of the loading categories other than air pollutants, such as on-sitehealth and safety impacts or land use and degradation, tend to be more highly site-specific, more difficult togeneralize to facilities in use in different countries or regions, and less linearly related to the quantity ofenergy produced or consumed. Thus, only a small fraction of the coefficients in EDB refer to these typesof effects The user can, however, add this type of information to EDB if it is available and relevant to aparticular study.

Section 5 of this Guide presents an overview of the application of LEAP/EDB to theenvironmental analysis of energy scenarios, with specific examples demonstrating how LEAP and EDB canbe used. The integrated energy-environment approach that underlies both this manual and the design ofLEAP and EDB is described in Box 1.1 below. In keeping with the considerable uncertainties in data andscientific understanding in the environmental field, the LEAP/EDB approach to environmental analysis issimplified and limited, yet still powerful. Because it provides an international database of emission factors,EDB provides planners with a "jump-start" in collection of environmental data. In the absence of localdata, default EDB data can provide useful initial estimates. When EDB data are linked to specific energyprocesses, LEAP can be used to illustrate how different energy strategies could yield different futureoutcomes in terms of emissions and impact indicators.

Introduction 5

Table 1.2 below provides a hypothetical table of LEAP/EDB results over a 15-year time horizon.Emissions and impacts are typically driven (caused to change in magnitude over time) by increasingeconomic activity, which leads to demands for energy services and the consequent consumption and

BOX 1.1:Steps in Integrated Energy-Environment Analysis

Three basic principles underlie integrated energy-environment analysis. First, the analysis considers allfuels and technologies, whether on the supply or demand side, on equal footing. Second, the ultimate goal is theprovision of end-use services and amenities (hot water, lighting, transport, etc.), rather than simply fuels orelectricity, at the least social cost. Finally, the broader analysis seeks to incorporate the economic externalities --most notably environmental and equity impacts -- absent from a traditional cost-benefit analysis based on marketprices alone. The necessary longer-term planning horizon (such as > 10 years), stretches beyond, but not inisolation from, the short-term issues that often dominate the planning realm.

The following six steps define an idealized process for conducting an integrated energy-environmentanalysis, and formulating environmentally-informed energy policy: Note that this process is usually carried out inan iterative manner, with later steps informing or suggesting modifications to previous steps.

1) Determine Planning Goals: The definition of the planning goals to be met will help to determine theextent of data that must be collected, the types of scenarios to be run, and the categories of results that will beneeded.

2) Characterize Baseline Energy Situation: This step involves the establishment of a reliable database forprojecting future energy needs, comparing technological alternatives, and evaluating policy impacts. Thecharacterization prepared may be for a particular project, a regional energy system, or anything level of aggregationin between. Additional data collection activities may be identified and undertaken.

3) Prepare Baseline Energy Scenarios: In this step a plausible baseline policy-neutral scenario (or set ofbaseline scenarios) that reflects "business-as-usual" growth and changes in the energy situation must be definedand quantified. This step involves collecting macroeconomic projections, demographic projections, and otherestimates or assumptions regarding likely future changes. These data are then entered into the analysis system.The initial results of these baseline scenarios should be reviewed for consistency and reasonableness, and to checkfor any data entry errors.

4) Prepare Alternative Energy Scenarios: . These scenarios reflect alternative evolutions of demographic,macroeconomic, technical, and/or policy factors. Development of alternative scenarios includes the investigation ofresource and technology options for improving end-use services at the lowest societal cost, including environmentalimpacts. This involves gathering data and judging the merits of various supply and demand options (new facilities,import/export options, efficiency improvements, fuel-switching). Cost curves can be used to as a screeningmeasure for developing scenarios.

5) Collect Environmental Data and Estimate Loadings related to processes and environmental issues ofconcern within the baseline and alternative scenarios. In addition to gathering appropriate emission factors, thisstep involves establishing the relevant cause-effect linkages (for example, does biomass energy use ⇒ landclearing ⇒ deforestation?), and characterizing the impacts that may be more difficult to measure or quantify (forexample, ecosystem harm or aesthetic impacts). Information on loadings and direct environmental impacts may,depending on the goals of the analysis, be used to model the transport fate, and responses of organisms and thephysical environment to pollutant discharges

6) Analyze policy options and implications, to determine how the least-cost, maximum-benefit scenario canbe achieved, and what additional costs might be involved (such as program/administrative costs, economic lossesor gains due to taxation or subsidies, etc.). Environmental externalities should be included in a comprehensive andsystematic fashion in whatever decision-guiding framework (for example, social cost-benefit analysis) is used. Otherexternalities -- most notably broader socio-economic impacts --should also be included.

Note that while different approaches to pollutant transport and dose-response modeling are discussed briefly inSection 6, they are generally beyond the scope of this guide.


production of various fuels. Emissions and impacts can also be modified by changing energy consumptionpatterns, fuel choices, energy loss levels, technology choices, and the development of new technologiesincluding pollution control and other mitigation measures. As discussed in Section 5, you can use a energy-environment modeling framework such as LEAP/EDB to create scenarios that explore the consequences ofpolicy interventions or alternative development patterns. Among other objectives, scenarios can seek tominimize or reduce projected loadings as a means to achieve more environmentally sustainable energydevelopment.

Table 1.2:Hypothetical LEAP/EDB Environmental Results Table

Base Case Scenario 1990 1995 2000 2005 UnitsAIR EMISSIONS Carbon Dioxide 100 150 200 250 1000 Tonnes Sulfur Oxides 5 10 15 15 TonnesWATER EMISSIONS Cadmium 20 30 40 40 KgSOLID WASTE Scrubber Waste 10 20 30 30 TonnesLAND USE Inundated Land Area 10 10 10 200 HectaresHEALTH AND SAFETY Lost Work Days 200 300 400 400 Person-Days

While falling short of providing actual accountings of environmental damage or costs, theemissions and on-site impact results from LEAP/EDB can provide important indicators of the direction ofenvironmental progress or deterioration with respect to key issues such as acid precipitation, greenhousegas emissions, toxic emissions, and air pollution. LEAP/EDB itself contains no models to determine thefate of pollutant emissions and their eventual health, ecological, aesthetic, and other damages.

As discussed in Section 6, physical damage estimation can be extremely difficult, and can requirerather detailed models of pollutant fate and transport, receptor (plants, animals, humans) exposure, anddose and stress-response. In many cases, such as global climate change, acid damage of sensitiveecosystems, or health impacts of traditional biomass cooking, scientific uncertainty as to the expectedextent of physical damages remains significant. Nonetheless, there is sufficient evidence in many cases toestimate the magnitude of likely damages, and to suggest that specific actions can reduce the risk of theseimpacts. Section 6 reviews some of the available models for impact and damage assessment. Due in partto their complexity, environmental damage models have generally not been extensively applied by energyplanners, despite the growing importance of environmental considerations in sifting among energy choices..

Finally, we turn to the most difficult and perhaps the most important question: how does oneincorporate environmental concerns into energy sector decisions? From a decision-making perspective, theintegration of different environmental damages into a single numeraire or variable would be ideal, in orderto compare strategies and technologies with very different types of impacts (for example. hydroelectric andcoal-fired power plants). Can, or should, loadings or damages be converted to monetary estimates,enabling their use in cost-benefit analyses? The monetization of environmental impacts — more precisely,environmental externalities, the economic term for costs not typically counted in market prices anddecisions — is proceeding at a rapid pace. In the U.S., for instance, 29 states have acted to incorporate

Introduction 7

environmental externality costs in electric sector planning4. Internalizing environmental costs has beentermed "the wave of the future", with 85 pollution taxes already in place by 1989 among OECD countries5.So-called market-based initiatives, are rapidly spreading worldwide. Although such initiatives remainrelatively rare among developing countries at present, there are exceptions, such as forestry levies aimed atreducing the environmental impacts of woodfuel harvesting (though these may be of questionable efficacybecause of enforcement difficulties).

There are many alternatives among monetization methods and many alternatives to monetization.Monetized values for emissions such as carbon dioxide or sulfur dioxide can be imputed from the costs ofemission control devices used to achieve a specified target level of emissions of a particular pollutant, orbased on the costs of the damage they lead to. Each method has distinct advantages and disadvantages.For practical or ethical reasons, monetization may be rejected in favor of ad hoc approaches toincorporating environmental concerns (e.g. subsides for certain environmentally-preferred options, such assolar energy), or other techniques such as multi-objective analysis. These approaches are reviewed in aSEI-B companion paper entitled Incorporating Environmental Externalities in Energy Decisions: A Guidefor Energy Planners. (Hill et al, 1994).

1.2 Challenges and Concerns in Quantitative Analysis

Three major challenges that face the planner who carries out a quantitative environmental analysisinclude: 1) the consideration of loadings and impacts that are difficult to quantify or generalize (forexample, ecological damage, soil degradation, and aesthetic impacts), 2) large uncertainties in relationshipsbetween loadings and damages; and 3) the comparison across seemingly incommensurate impacts (such asbalancing human health, ecological, and economic costs and benefits). In particular, for energy sourceswith extensive land-use impacts such as woodfuel plantations and hydroelectric or geothermal facilities, theoverwhelming influence of site-specific factors (local climate and ecology, land use patterns) rendergeneralized models very difficult. The danger of biasing energy choices towards those options whoseenvironmental impacts are most difficult to assess or quantify -- "confusing the countable with the thingsthat count" -- must be avoided.

A few caveats will be echoed throughout this guide:

• there is no single or straightforward recipe for including environmental concerns in energyanalysis;

• ease of quantification can be seductive, and an initial prioritization of concerns is thusimportant in order to avoid unnecessary focus on easily countable impacts that may be ordersof magnitude less important than more intractable environmental and/or social issues;

• environmental impacts are complex, often non-linear (that is, not varying directly with theamount of energy consumed or even the amount of a pollutant released), with pathways thatcan depend on factors beyond the general scope of the energy sector (such as

4 Of these, 19 states have issued orders or passed legislation requiring utilities to include these costs in planning or newcapacity bidding processes. R. Ottinger, "Consideration of Environmental Externality Costs in Electric Utility ResourceSelections and Regulation", in Energy Efficiency and the Environment: Forging the Link, Vine, E. et al., eds. AmericanCouncil for an Energy-Efficient Economy, Washington, DC, 1991.5 Ibid , p. 190.


biomass/deforestation linkages, the connection between settlement and transportation patternsand urban air pollution, etc.);

• there are no easy, objective methods for comparisons across classes of impacts (human health,agricultural production, aesthetic value, etc.). Since some method of numerical valuation ofenvironmental impacts (such as ranking or the application of externality costs) is inevitablyrequired, difficult and often rather subjective judgments must be applied.

With these caveats in mind, one can nonetheless usefully apply tools of integrated, quantitativeenergy-environment analysis. The use of tools such as LEAP/EDB may only lead to partial answers interms of environmental outcomes and costs, but these can be important inputs for use in directing energypolicy toward more sustainable paths. Other complementary and non-quantitative approaches must also beconsidered, including the comparative environmental assessments noted above. The alternative to theintegrated analysis of the environmental impacts of energy choices is quite often a “business-as-usual”mode where the consideration of environmental issues in energy policy decisions is limited to immediatecrises (such as deforestation and a perceived linkage to energy) or funders' concerns (as has to a largedegree precipitated the recent spate of global warming analyses). This "reactive" mode generally fails toavoid foreseeable problems or address long-term local concerns. Attention then focuses on more costlymitigation actions (clean up, reforestation, sea wall construction, etc.). Planting trees and/or restrictingaccess to an area in order to help regenerate a natural forest is, for example, almost inevitably moreexpensive and difficult to achieve than are the alternatives to land clearing. An ounce of prevention, as thesaying goes, is worth a pound of cure. As described in the next section, we are now faced with numerousglobal, regional, and local environmental concerns that require a rethinking of energy policy, and theapplication of appropriate analytical approaches and tools, to avoid the “pound of cure”.

Introduction 9

Table 1.3:Glossary of Terms as Defined in this Guide

Biodiversity: The extent to which an ecosystem has a few or many different species and types oforganisms is termed its biodiversity. While some ecosystems naturally have relatively few differenttypes of organisms (arctic ecosystems are examples here), ecosystems with a greater diversity are often(though not universally) thought to be more “healthy” and robust. Loss of biodiversity can occur as aresult of pollutant stresses, land use change, over-harvesting of plants or animals, or changes in climate.

Deforestation, Desertification, Devegetation, or just plain Degradation: These terms refer to theprocess by which lands which formerly were covered by forests or woodlands are changed, by timber orfuelwood harvesting, fire, clearing for agriculture, or other land-use changes, to lands that have reducedbiomass productivity and reduced vegetation cover. In the extreme case of desertification, the loss ofvegetation on lands in dryer climates can allow desert land types to encroach and take over.

Dose/Response: The relationship between the amount of a pollutant (or other chemical) absorbed orapplied to a plant or animal (or area of an ecosystem) and the effect of that pollutant. Doses are oftenmeasured in terms of unit mass of pollutant per unit mass of plant or body weight (milligrams per kg, forinstance) or per unit area or volume. Responses may be a fraction of the population likely to die orbecome ill, or other changes.

Ecosystem: This is a generic term for a system that includes a community of organisms, includinganimals, plants, and microorganisms, and their interactions with the environment (Freedman, 1989).

Effect: Effects, as used in this Guide and in EDB, are the direct results, including environmentalloadings (see below) and direct health and safety impacts, of the operation of energy technologies.Examples of effects include carbon dioxide emissions to the atmosphere, emissions of mercury to water,solid wastes applied to the land, and accidental injuries during fuel extraction.

Emission Factor or Coefficient: A quantitative measure of the emission of a pollutant per unit ofenergy use, transformed, or produced by a given energy technology. Examples here are kilograms ofcarbon dioxide per tonne of coal burned, or grams of slag produced per tonne of oil shale processed.

Energy Processes refer to the combination of technological, behavioral, and operational conditions. Aprocess can be as precise as a specific as oil refinery, where on-site measurements have been madeand its operation is simulated in LEAP. Or it can be as general as an average for all industrial boilers.The detail of process specification will depend on the nature of the scenario building exercise andavailable data on loadings.

Impact: An environmental impact of an energy-sector device or process is what happens to plants,animals, humans, or ecosystems as a result of the use of that device or process. Direct impacts arethose that occur as a direct result of the use of the device or process, such as mining deaths occurringduring coal extraction. Indirect impacts require the transport of a pollutant or some other link betweenthe energy device or process and the ultimate environmental effect. The impact of sulfur dioxideemissions from fuel combustion on lung disease would be called an indirect impact because the sulfurdioxide must be transported (in the air) between the site where the fuel is used and the person affectedby the emissions.

Loadings: Loadings include air and water emissions, land use and materials requirements, landdegradation and habitat loss, and on-site health and safety impacts. Loadings, as we use the term here,do not include indirect impacts -- such as the emissions from the waste disposal vehicles in the coalpower plant example cited earlier in Section 1 -- or impacts and stresses that occur beyond theimmediate site of energy use. For example, a coal plant's loadings would include nitrogen oxide andsulfur oxide emissions from the stack, but not the tropospheric ozone and acid precipitation that mightresult from the emissions due to atmospheric chemistry and pollutant transport.


Table 1.3 (continued):

Loading Factors: These are typically expressed in loadings (see above, and also see the definition foremission factors) divided by the unit of energy flow of an energy process. Loading factors includeemission factors for air and water emissions or indicators of on-site health and safety risks (for example,1 injury per 100,000 tonnes coal mined). The appropriate measure for energy flow, the denominator ofthe loading factor, depends upon the process considered. (See Section 4) For instance, the emissions ofsulfur oxides (SOx) from a coal-fired electric facility can be expressed in terms of grams per kilowatt-hourproduced or tonnes of coal consumed. In either case, the relationship between energy flow and loadingsfor a given process is linear. That is, if electricity production from a facility doubles, without any otherchanges, the use of a single factor implies that loadings will double as well. While for many loadings,carbon dioxide emissions from fossil fuel combustion being a prime example, this simple relationshipholds, for others, such as land use by hydro or other energy facilities, the relationship is less clear.

Medium/Media: These are the parts of the ecosystem to which pollutants are discharged, including theatmosphere (air), rivers, stream, lakes, and oceans (water), and land (soil). The media to which apollutant is discharged determines in large part the way in which it is transported to the organisms andecosystems it affects.

Pathway: The way in which energy use, production, or transformation exerts an influence on (affects) areceptor (see below) is the pathway by which the impact occurs.

Receptor: A receptor is a plant, animal or ecosystem affected by an energy system, either directly (suchas coal mining accidents) or indirectly through pollutant emissions or other effects.

Stress: Stress defined by Freedman (1989) as the physical, chemical, or biological constraints that limitthe potential productivity of the biota [the plants and animals in an ecosystem]. Any environmentalinfluence that causes measurable ecological detriment.” An air pollutant that reduces the growth of aplant would be exert a stress on that plant.

Major Environmental Problems Associated with Energy Activities 11

2. Major Environmental Problems Associated with Energy Activities

2.1 Introduction

The connection between energy use and environmental degradation is not surprising. From thepolluted air of many urban areas to denuded hillsides that no longer provide easy access to woodfuels, thesigns of this connection are increasingly visible. Acid rain, oil spills, global warming, toxic wastes, habitatloss, population displacement: the number of environmental issues associated with energy activities is bothalarming and challenging to those seeking to address them in a comprehensive manner. Adding to thischallenge are the many dimensions of each problem, from their underlying causes (for example, poverty orinfrastructure policies) to their final impacts. As depicted in Figure 2.1, numerous factors can influence thenature and extent of environmental damages, and consideration of these factors can suggest differentoptions for reducing environmental impacts.

Although this document is focused upon the linkages between energy activities and environmentalloadings and damages, the importance of other dimensions cannot be overlooked6. Underlying dynamicsand causal factors related to development and socio-economic relations can either foster or undermineotherwise well-intended policies (witness, as an example, the difficulties encountered by many reforestationand wood-energy plantation efforts). Transport of emissions can lead to trans-boundary problems, such asacid deposition and global warming, that cannot be resolved solely on a national level. There are alsobroader issues of who benefits and who loses with environmentally damaging activities. It has been saidthat woodfuel issues cast an urban shadow over the rural areas that bear the brunt of the impacts of woodharvesting, as few rural residents benefit from this resource extraction. A similar argument can be madeabout global warming under the current North-South patterns of fossil fuel use and related carbon dioxideemissions, as depicted in Figure 2.2.

6 For a discussion of the models and approaches for looking at some of the other aspects of the system, for example, transport-impact models, etc., see World Bank. Environmental Assessment Sourcebook, Volumes I-3, Environment Department, WorldBank Technical Paper 139, Washington DC, 1991. The approach described here is not intended to substitute for, rather tostimulate, more thorough project-specific environmental analysis, such as that typically undertaken in an Environment ImpactAssessment.

Figure 2.1:Selected Pathways from Energy Activity to Environmental Damage

InfrastructureEconomicAgricultural PoliciesFinancial ConstraintsPovertyLand Tenure

Facility ConstructionFuel ExtractionRefining& ConversionFuel Combustion

Air & Water EmissionsSolid WasteLand ClearingPopulation Displacement

EcosystemHuman HealthAestheticsLand DegradationBiodiversityEconomic Harm

UNDERLYINGCAUSES

ENERGYACTIVITY

ENVIRONMENTALEMISSION/INSULT

TRANSPORT RESPONSE/DAMAGE

AirWaterSoil

Consumption Patterns


Figure 2.2:The Regional Pattern of CO2 Emissions from Fossil Fuel Combustion

kg CO2 per Capita

0 5,000 10,000 15,000 20,000

S&E Asia

Africa

CP Asia

L. Amer.

Mid. East

W. Eur.

Oceania

E. Eur/SU

N. Amer.

This chapter groups the major energy-environmental issues by relative geographic scale ofimpact: global, regional, and local. Impacts with a global scale may originate from local activities,which, due to the longevity and transport of emissions, or to the nature of the impact, affect globalenvironmental conditions. These issues include global climate change from greenhouse gas emissions,stratospheric ozone depletion, and habitat destruction with the associated reduction of global biodiversity.In contrast, some energy activities result in emissions (e.g. acid precursors, SOx and NOx, or themobilization of long-lived toxic contaminants) that lead to damage tens or hundreds of kilometers away.We refer to these as regional issues. Finally, local issues refer to situations where impacts generally occurat or near the site of energy use or production, such as indoor and urban air pollution, groundwatercontamination, and solid waste production.

The groupings that we use, shown in Table 2.1, are far from definite or universal. Theclassifications are intended to suggest the scope of analysis and action necessary to address each issue. Forexample, global and regional concerns are more likely to involve transboundary issues requiringcooperation between countries, such as international or regional agreements necessary to mitigate sourcesof pollution, and may be more difficult to fully address on a solely national or subnational basis.


2.2 Global Issues

While some environmental issues are either so widespread (such as oil spills) or have impacts thatcan be sufficiently far removed from their source (radioactive emissions) as to arguably be consideredworld-wide in scope, three issues most clearly have implications for the well-being of the entire planet.These are global climate change, sometimes (but not entirely correctly) referred to as "the greenhouseeffect", the depletion of stratospheric ozone, and reductions in biodiversity. The first two issues areoccasionally confused, since some of the same chemical compounds have roles in both processes, but theypose quite distinct threats.

2.2.1 Global Climate Change

"Global warming", “climate change”, and the "greenhouse effect" are common expressions used todescribe the threat to human and natural systems resulting from continued emissions of heat-trapping or“greenhouse” gases (GHGs) from human activities. These emissions are changing the composition of theatmosphere at an unprecedented rate. While the complexity of the global climate system makes it difficultto accurately predict the impacts of these changes, the evidence from modeling studies, as interpreted by theworld’s leading scientists assembled by the Intergovernmental Panel on Climate Change (IPCC), indicatesthat global mean temperature will increase by 1.5 to 4.5º C with a doubling of carbon dioxideconcentrations, relative to pre-industrial levels7. Given current trends in emissions of greenhouse gasses,this doubling--with its attendant increase in global temperatures, would likely happen in the middle of the

7 Intergovernmental Panel on Climate Change. 1992. Climate Change 1992: The Supplementary Report to the IPCC ScientificAssessment. J. T. Houghton, B. A. Callander and S. K. Varney, eds. Cambridge, U.K.: Cambridge University Press, p.5.

Table 2.1:Major Energy-Environment Issues by Scale

GLOBAL ISSUESo Global Climate Changeo Stratospheric Ozone Depletiono Reduction of Biodiversity

REGIONAL ISSUESo Water and Land Use and Degradationo Ocean Contamination (Oil spills, etc.)o Mobilization of Toxic Contaminantso Acid depositiono Radioactivity and Radioactive Wastes

LOCAL ISSUESo Urban Air Pollutiono Indoor Air Pollutiono Localized Surface and Groundwater Pollutiono Solid and Hazardous Wasteso Electromagnetic Fieldso Occupational Health and Safetyo Large Scale Accidents

o Aesthetic and Other Concerns (e.g. Audible Noise, Visual Impairment)


21st century. For reference, a global increase of 2º C from today’s levels would yield global averagetemperatures exceeding any the earth has experienced in the last 10,000 years, and an increase of 5º Cwould exceed anything experienced in the last 3,000,000 years. Moreover, it is not simply the magnitudeof the potential climate change, but the rate of this change that poses serious risks for human andecosystem adaptation, with potentially large environmental and socioeconomic consequences.

The greenhouse effect itself is a relatively well-understood natural phenomenon, first mentioned asearly as 1827 in a paper by the physicist-mathematician Jean-Baptiste Fourier. The earth receives arelatively constant amount of energy from the sun in the form of incoming solar radiation. The atmosphereand surface of the earth reflects some of this radiation, most of which is in the form of visible light, directlyback into space, but absorbs the majority. An amount of energy equal to that in the radiation absorbed isultimately re-emitted to space as thermal (heat) or "outgoing" radiation, thereby maintaining an energybalance between incoming and outgoing energy. This balance keeps the earth’s temperature at anequilibrium level. Figure 2.38 below shows the basic mechanisms of this "greenhouse effect".

Figure 2.3: The Greenhouse Effect

The essence of the greenhouse effect is that particular trace or “greenhouse” gases in theatmosphere absorb some of the outgoing radiation on its way to space from the surface of the earth. Thesegases, principally water vapor (H20), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), andozone (O3), together act as a transparent atmospheric "blanket" that allows sunlight to warm the earth butkeeps infra-red radiation (heat) from leaving the earth and radiating out to spaceWithout this atmospheric “blanket” of trace gases, the equilibrium surface temperature of the earth wouldbe approximately 33° C cooler than today’s levels, averaging -18ºC rather than +15ºC, and making theearth too cold to be habitable. It is this blanketing effect of the atmosphere that is referred to as thegreenhouse effect. A greenhouse is a useful analogy; the atmosphere behaves somewhat like the glass paneof a greenhouse, letting in visible or short-wave radiation, but impeding somewhat the exit of thermalenergy, thereby increasing the equilibrium temperature inside the greenhouse.

The present concern with global warming does not center on the natural greenhouse effect of theatmosphere on global equilibrium temperature and climate. Rather, it arises from the potential additional

8 After IPCC, 1990.

ATMOSPHERE

EARTH

Some solar radiation is reflectedby the earth and the atmosphere

Solar radiationpasses throughthe clearatmosphere

Most solar radiation isabsorbed by the earth’ssurface and warms it

SUN

Infra-redradiation isemitted from theearth’s surface.

Some of the infra-red radiation isabsorbed and re-emitted by thegreenhouse gases. The effectof this is to warm the surface andthe lower atmosphere.


global warming that may occur due to the rapidly increasing concentrations of heat-trapping greenhousegases. Measurements taken at remote locations around the globe have revealed that current concentrationsof greenhouse gases in the atmosphere substantially exceed their pre-industrial levels. The primary humanactivities that are responsible for this growth in atmospheric concentrations of these gases are thecombustion of fossil fuels and the reduction of carbon stored in biomass through conversion of forests andother natural land types to settlements, agricultural land, and other uses.

The combustion of all carbon-based fuels, including coal, oil, natural gas, and biomass, releasecarbon dioxide (CO2) and other "greenhouse gases" to the atmosphere. Over the past century, emissions ofgreenhouse gases from a combination of fossil fuel use, deforestation, and other sources have increased theeffective "thickness" of the atmospheric blanket by increasing the concentration of greenhouse gases (orGHGs) in the troposphere, or lower part of the atmosphere (ground level to about 10-12 km). It is this"thicker blanket" that is thought to be triggering changes in the global climate. Table 2.2 lists the mostimportant greenhouse gases, together with their major sources, current concentrations, and the rate at whichthey have recently been increasing in the atmosphere.


A number of gases may also indirectly affect global climate. Carbon monoxide (CO), nitrogenoxides (NOx), non-methane hydrocarbons (NMHC), and methane are all thought to contribute indirectly toglobal warming by affecting the atmospheric concentration of other greenhouse gases (such as troposphericand stratospheric ozone)10. Because of incomplete understanding of the chemical processes involved, theseindirect contributions to warming are more uncertain than the contributions of the direct greenhouse gases(CO2, CH4, N2O, CFCs). This is reflected in the recommendation that indirect global warming potentials(GWPs), indicators of the relative warming effects of each gas, are no longer suggested by the IPCC forCO, NOx, NMHC, and CH4. In its 1992 Supplement to its original 1990 Report, the IPCC stated thatearlier reported indirect GWP values “are likely to be in substantial error, and none of them can be

9 Based on Leggett, 1990, IPCC, 1990, IPCC 1992, and IPCC 1994.10 Methane has both direct and indirect effects.

Table 2.2:Overview of Common Greenhouse Gases9

Gas Principal Sources

Current Rate ofEmissions andIncreasingConcentration

Global WarmingPotential (100-

year timehorizon)

ApproximateContributionto Warming

Carbon Dioxide(CO2)

- Fossil Fuel Combustion- Deforestation- Cement Manufacture

- 26,000 Tg/yr emitted- 0.5%/yr increase inconcentration

1 84%

Methane (CH4) - Natural Gas and Oil Production- Natural Gas Pipelines- Coal Mining- Fossil Fuel Combustion(minor)- Agriculture (Rice Cultivation,Enteric Fermentation)- Waste Disposal

- 300 Tg/yr emitted- 0.9%/yr increase inconcentration

24.5 11%

Nitrous Oxide (N2O) - Fossil Fuel Combustion(minor) - Biomass Burning- Agriculture (Fertilizer Use)

- 6 Tg/yr emitted- 0.8%/yr increase inconcentration

320 5%

Chlorofluorocarbons(CFCs) and relatedGases (HFCs andHCFCs)

- Industrial Uses IncludingRefrigerants, Foam Blowing,Solvents, Fire Retardants

- 1 Tg/yr emitted- 4%/yr increase inconcentration

140-12,100,depending on gas

--

Gases That May Have Indirect Effects on Climate Change

Carbon Monoxide(CO)

- Fossil Fuel Combustion(especially vehicles)- Biomass Burning includingBiomass Fuel Combustion

- 200 Tg/yr emitted -- --

Nitrogen Oxides(NOx)

- Fossil Fuel Combustion- Biomass Burning


Non-MethaneHydrocarbons

- Fossil Fuel Combustion- Solvent Use



recommended.”11. The GWP values shown in Table 2.2 are from the latest IPCC Assessment (IPCC1994, page 28).

Some gases may have cooling effects as well. Recent evidence suggests that the overall role ofchlorofluorocarbons (CFCs), once thought to be major contributors to global warming, is no longer clear.By reducing the concentration of stratospheric ozone, CFCs may have a cooling effect approximatelycanceling out the direct warming effect of the CFC molecules themselves. The emission of sulfurcompounds (such as SO2), which leads to the formation of sulfate aerosols, may have a cooling effect in theNorthern Hemisphere. However, this cooling effect, like the sulfate aerosols themselves, is highly localizedand relatively short-lived.

The role of water in the atmosphere is complex. Global warming will increase evaporation, andthus increase moisture in the atmosphere. Since water vapor acts as a greenhouse gas, this leads awarming feedback effect12. Increased water vapor will also likely increase cloud formation. However, thenet feedback effect of cloud formation is uncertain, depending on the type of clouds that are formed, sincewater vapor in clouds can both reflect incoming sunlight and trap outgoing radiation.

While the extraction, transportation, and use of energy is not the only source of greenhouse gases,the sector contributes, all told, more than half of the overall commitment to global warming. Thoughcarbon dioxide from fossil fuel combustion is the best known and most important greenhouse gas,combustion also releases other GHGs, and fossil fuel extraction, transmission and distribution areimportant sources of methane and other hydrocarbons, as shown in Table 2.2.

Under ideal conditions, the use of biomass fuels will not lead to net CO2 emissions. Plants take upcarbon dioxide as they grow to construct the organic (carbon-containing) biological molecules that make upthe bulk of their (dry) mass. When the biomass in the plants is eaten, burned, or decomposes, the carbonis released again (in large measure) as CO2, and is returned to the pool of carbon dioxide in the atmosphere.This recycling is part of a natural process called the carbon cycle. If the rate at which biomass isharvested for fuel is balanced by the rate of biomass growth, then no net CO2 emissions will occur. Incases where biomass is removed but does not (or is not allowed to) grow back, the use of biomass fuels usecan yield net CO2 emissions. This is the case in instances where fuelwood consumption in a region takesplace at a rate faster than forests can grow back, or when carbon in the soil is depleted by sub-optimalforestry or agricultural practices.

While there is now general (but not total) agreement among atmospheric scientists that increases inatmospheric concentrations of GHGs will result in an average increase in global temperatures -- assumingcurrent rates of emissions continue -- some uncertainty remains. There are complicated interactions and"feedbacks" between the atmosphere, the oceans, the continents, and the biosphere. While very powerfuland complex climate models now exist for analyzing the interactions between GHG emissions and climate,there still remain major scientific uncertainties and modeling challenges yet to be solved. For example,when measurements of the rate at which CO2 concentrations are increasing in the atmosphere are comparedwith the rates at which CO2 is estimated to be emitted by fossil fuel combustion, it appears that a 11 IPCC 1992, p. 14-15.12 A feedback happens when a change in some quantity B brought about by a change in A has a further effect, or feedback, onA itself. When your body becomes too hot, for example, water evaporates from your skin at a greater rate, and you cool down.This is called a negative feedback, as the change in the second variable (evaporation) reduces the first (skin temperature). Anexample of a positive feedback loop with several links that involves the energy sector might be the following: Increased use ofair conditioning leads to increased emissions of GHGs, which increases levels of GHGs in the atmosphere, which leads tohigher global temperatures, which leads to further increased use of air conditioning.


substantial amount of the fossil carbon dioxide is "missing", that is, is not present in the atmosphere. Whilevarious "sinks", or places in the earth/ocean/atmosphere system where this CO2 may have ended up, havebeen postulated -- most notably, the deep, relatively unmixed portions of the oceans -- the uncertainty inthis key parameter underscores lack of complete understanding of the full suite of climate systeminteractions.

In addition, our climate has quite a lot of natural variability on many scales -- year-to-year,century-to-century, millennium-to-millennium, and longer. This natural variability, as shown by the cyclesof cooler and warmer periods13 has made definitive detection of warming induced by human activitydifficult. Compounding this problem in detection are the effects of other events beyond human control.Large volcanic eruptions, for example, can inject large amounts of dust into the stratosphere, the part ofthe atmosphere lying above the troposphere, which can cause global temperature to be slightly cooler thanthey would have been, sometimes for several years. For example, the recent eruption of Mount Pinatubo inthe Philippines threw sufficient debris into the stratosphere to explain, according to several climatemodellers, the cooler temperatures experienced globally in 1992. This drop broke a trend of steadilyincreasing global average temperatures. Seven of the eleven warmest years in recorded history occurred inthe 1980s, and 1991 was the warmest year ever.

Warming of the earth may, in turn, have numerous secondary effects, some of which havepotentially serious impacts of the well-being of both humans and the plants and animals with which weshare this planet. These effects include an increase in sea levels due to melting of polar ice, changes inprecipitation patterns, and changes in vegetation. The timing and spatial distribution of these effectsaround the globe are as yet extremely uncertain. The implications of these effects on human populationsare discussed briefly below.

• Sea level rise. Two processes could contribute to this phenomenon: thermal expansion of theoceans, and melting of polar ice caps, snow cover and glaciers. Many coastal communities,particularly those in large alluvial flood plains and low-lying islands, are particularly vulnerable.Low-lying cities and croplands may be partially submerged and/or subject to more frequentflooding by tides and storms, and highly productive coastal ecosystems that humans depend on --particularly estuaries -- may suffer a loss in productivity. This loss in productivity is due both toincreasing salinity of surface and ground waters and to increasing water levels. Furthermore, ashighly reflective polar and glacial ice and snow melt to expose less-reflective earth or open seawater, the earth becomes a better absorber of solar radiation. This may further increase the rate atwhich global temperatures rise. Similarly, as the arctic tundra warms, methane could be releasedfrom methane hydrates14 and contribute to further warming.

• Increased climatic variability and storm intensity: Changes in temperature are likely to createchanges in wind and precipitation patterns; that is, some places will become wetter, others drier. Inaddition, the timing of wet and dry seasons may change, and what precipitation does fall may do soin a more concentrated fashion (i.e. as storms) or more gradually. At present the various climatemodels are not in full agreement as to which regions will be affected in what way, but given theimportance of rainfall patterns on the ability of agriculture to sustain human populations,particularly in heavily populated areas (southeast Asia, for example), any changes in precipitationare of concern. Another prediction of some climate models is that severe storms, includingtropical typhoons and hurricanes, will become more frequent and/or more severe, posing an added

13 See, for example, Leggett, 1990, pages 20 and 21.14 Methane hydrates are molecules of methane “locked up” with water molecules in ice structures. When these structuresmelt, the methane molecules are released to the atmosphere as methane gas.


threat to coastal and island populations. Finally, changes in precipitation will affect theavailability and quality of fresh ground and surface waters.

• Changes in vegetation: Changes in the distribution of plants brought on by changes in temperatureand precipitation also have implications for human well-being. Some interpretations of climatemodel results show the "grain belts" of the Northern hemisphere shifting north by hundreds ofkilometers. However, it is uncertain whether the full set of conditions to maintain agriculturalproductivity will remain. Forests, animal habitats, and ecosystems as whole may be unable totolerate climatic changes, may be unable to migrate as quickly as climates shift to other areas. Atthe same time, higher levels of CO2 in the atmosphere increase the rate at which certain plantsgrow (all else being equal and assuming no other growth limiting factors), and higher temperatureswould benefit some plant species, while being detrimental to others.

For a detailed discussion of these and other climate change concerns, see the compendium of essaysin SEI's recent volume on Confronting Climate Change, 1992, Mintzer, I. ed.

2.2.2 Stratospheric Ozone Depletion

Depending upon where it occurs, ozone (O3) plays two very different roles in the atmosphere. Inthe troposphere, where it is the produced through the interaction of sunlight, NOx, and VOCs15, ozone canbe a major local and regional air pollutant that can cause acute respiratory symptoms and damage tomaterials, crops, and forests. Tropospheric ozone is also a greenhouse gas (see above).

In the stratosphere, however, ozone is naturally occurs in much higher concentration and it plays adifferent, beneficial role. The stratospheric ozone layer intercepts much of the ultraviolet (UV) part of theradiation emitted by the sun. Invisible to the human eye, this UV radiation increases the risk of skincancers, cataracts, and immune system problems in humans.

In recent years, dramatic reductions in stratospheric ozone concentrations, up to 50% in some polarregions, have been recorded. Smaller reductions of 5-10% have been detected in middle and upperlatitudes, while tropical regions appear to be unaffected thus far. Sustained reductions of 10% in ozoneconcentrations could lead to a 25% increase in non-melanoma skin cancers and a 7% increase in eyedamage from cataracts. (World Bank, 1992).

Furthermore, exposure to UV radiation can damage agricultural yields, phytoplankton (an essentialfood chain element of marine environments), and terrestrial ecosystems in two general ways. First,ultraviolet light causes damage to biological functions in plants and microorganisms, which can result instunted growth and lowered viability. Second, UV radiation can modify the genetic material in plant andanimal cells (DNA), resulting in potential damage to cell function and mutations that can influence theviability of seeds, pollen, eggs and sperm16. Since some species are more resistant to UV radiation thanothers, increases in such radiation could alter the species balance in some ecosystems. Increased levels ofUV radiation also accelerate the degradation of some materials, such as paints and plastics.

15 Volatile Organic Compounds, a broad class of emissions that includes many of the same species of hydrocarbon moleculesas Non-Methane Hydrocarbons (previously mentioned), as well as methane itself.16 Recently, articles in the journal Science have suggested a link between increase UV radiation and the reduction in thenumber of amphibians in many locations. Amphibian eggs, which often include a transparent “jelly”-like layer around thedeveloping embryo, are thought to be particularly sensitive to UV radiation.


Several human activities can lead to the stratospheric ozone destruction. In the early 1970's,concern over the ozone-depleting potential of water vapor and nitric oxide in the exhaust of a proposed fleetof super-sonic transport (SST) planes played a major role in limiting the deployment of SSTs17.Chlorofluorocarbons (CFCs), however, pose the largest and most immediate threat to the ozone layer.Certain energy-sector equipment -- most notably electric refrigerators and air conditioners -- contain CFCs,which are also used for purposes such as cleaning of computer chips and in plastic foam manufacture.Released through leakage or when old appliances are discarded, CFCs rise to the stratosphere, wherereaction with sunlight can yield free chlorine, a catalyst for ozone destruction. (see Box 2.1, below).

Mounting international concern led to signing of the Montreal Protocol on Substances that Depletethe Ozone Layer in 1987, with subsequent amendments that commit the signatory governments to a phase-out of CFCs and similar substances in industrialized and developing countries by the years 2000 and 2010,respectively. The phase-out of some CFCs have already begun, and some industries are finding that thecosts of finding and using alternatives to ozone depleting substances is less than expected18.

The principal intersection between the energy sector and ozone depletion lies in demand-sidemanagement programs that affect the stock and fate of CFC-containing appliances, or in applianceefficiency standards that influence the design or import of new equipment. (A highly touted U.S. EPAprogram entitled "Golden Carrot", has offered financial incentives to manufacturers of high-efficiency low-CFC refrigerators.) In addition, demand-side management (DSM) programs that encourage thereplacement of existing inefficient equipment with more efficient models can accelerate CFC release in theabsence of measures to reclaim the used CFCs.

17 The only SST in commercial use, the French/British "Concorde", has a smaller engine and is lower-flying than the US fleetof SSTs that was proposed, and thus poses less of a threat.18 For example, CFC-based solvents used for cleaning electronic parts are being replaced, in part, by inexpensive, water-basedsolvents based on citrus products.


2.2.3 Biodiversity and Habitat Loss

Biodiversity is perhaps the most discussed ecological issue of recent years. The variety of livingorganisms may be significantly affected by human activities associated with energy supply and use,particularly those that lead to local or global climate change or alter land use patterns. The term"biodiversity" encompasses not only the variety of plant and animal species -- including the less visibleworld of microscopic plants, insects, fungi and bacteria -- inhabiting a given area, but also the geneticvariability inherent among individual organisms within a species, variability that contributes to the abilityto adapt to changing circumstances. Scientists have identified and named about 1.7 million of theestimated 10 to 30 million species (Freedman, 1989) that inhabit the earth19. An estimated 86 percent ofthese species inhabit tropical regions.

Freedman (1989)20 summarizes three classes of reasoning -- philosophical, utilitarian, andecological -- that argue for the maintenance of biodiversity:

"1. One class of reasons is essentially philosophical, and it revolves around the esthetics ofextinction. The central questions are (1) whether humans have the right to act as the exterminatorof unique and irrevocable species of wild biota and (2) whether human existence is somehowimpoverished by the tragedy of anthropogenic extinction [extinctions caused by humans]. These

19 Note that 10 to 30 million species may be an under-estimate--some researchers argue for an ultimate figure on the order of100 million.20 Page 267.

BOX 2.1:THE PRODUCTION AND DESTRUCTION OF STRATOSPHERIC OZONE

Ehrlich, Ehrlich and Holdren (1977) describe the process of stratospheric ozone production anddestruction as follows:

"The stratospheric pool of ozone is the result of a balance between continuous processes thatproduce and destroy this substance. (The size of the pool varies with latitude and with time in responseto a variety of natural factors.) Production takes place when molecular oxygen (O2) is split by ultravioletsolar radiation and the resulting oxygen atoms (O) attach themselves to other oxygen (O2) molecules:

O2 ----> O + OO + O2 ----> O3.

"Destruction takes place by means of several different reactions, in which the net results areeither:

O + O3 ----> O2 + O2

or2 O3 ----> 3 O2.

"The destruction reactions proceed most rapidly in the presence of certain catalysts [moleculesthat chemically speed up the reactions]: the hydroxyl radical HO (which comes from water vapor in thestratosphere), nitric oxide (NO) and atomic chlorine (Cl). All of them are scarce in the naturalstratosphere, although crucial to its chemistry. Activities of civilization that change the stratosphericconcentrations of these catalysts also change the rate at which ozone is destroyed, thereby altering theproduction-destruction equilibrium and possibly reducing the atmospheric pool of ozone."


are deeply philosophical issues, and they are not scientifically resolvable. However, it is certainthat few people would applaud the extinction of a unique species of organism.

"2. A second class of reasons is more utilitarian. Humans are not isolated from the biosphere.We take advantage of other organisms in myriad ways for sustenance, shelter, and other purposes,including the functions that they may play in regulating or carrying out ecological processes. Ifspecies become extinct, then their unique biochemical, ecological, and other properties are nolonger available for actual or potential exploitation by humans.

"3. The third class of reasons is essential ecological, and involves the possibly essential roles ofspecies in maintaining the stability and integrity of ecosystems, and their roles in nutrient cycling,productivity, trophic dynamics, and in other important aspects of ecological structure and function.In only a very few cases do we have sufficient knowledge to evaluate the ecological ‘importance’ ofparticular species. It appears that an extraordinary number of species could disappear in thecurrent wave of anthropogenic extinctions before they have been studied in this respect."

The Box 2.2, below, describes an example of the utilitarian value of biodiversity, the case of anobscure tropical plant that has become important to human well-being and commerce, the rosy periwinklefrom Madagascar.

Several energy supply options can affect biodiversity, as listed in the Box 2.3, below. Facilityconstruction and resource extraction can disturb natural land areas and thereby endanger sensitiveecosystems. By their nature, some energy resources -- surface-mined coal, biomass, solar, and wind --imply particularly large land requirements. However, the extent of actual harm depends on several factors,including the previous land use, the sensitivity of local ecosystems, the reversibility of changes, and thespecific practices employed. In some cases, such as degraded land converted to a multiple-species biomassplantation, biodiversity might actually be enhanced. Measures such as reclamation can reduce the impactsof coal surface mining (the removed soil is pushed back over the area mined and the area is replanted), butthe original flora and fauna may not fully return. Central-station solar technologies can cover large desertor other ecosystem areas, while roof-top solar collectors ostensibly sacrifice little in terms of naturalhabitat. Hydroelectric developments inundate areas behind dams and change the timing and amount ofwater and sediment flows below them, potentially affecting diversity in aquatic ecosystems and the other

BOX 2.2:AN EXAMPLE OF THE DIRECT ECONOMIC VALUE OF BIODIVERSITY

(Adapted from Freedman, 1989)

The rosy periwinkle is a flowering plant found on the island of Madagascar, off the coast ofsouthern Africa. By chance, this plant was included in a screening of a wide sample of different wildplants for their possible cancer-fighting properties. Its extracts were found to counteract thereproduction of cancer cells, and the plant was subsequently found to contain compounds of the typecalled "alkaloids", which the plant itself probably contains to make it unpalatable or toxic to insects andother herbivores (plant-eaters). The use of drugs based on these compounds--it takes 530 kg of plantmaterial to make just 1 gram of drug worth $200--has been notably successful in treating several types ofhuman cancers, including Hodgkin's disease and childhood leukemia. As the rosy periwinkle's naturalhabitat is currently threatened by expanding agriculture and lumber harvesting, it is fortunate that itsbeneficial properties were discovered before it became extinct. Thus, even to those who might contendthat human needs and commerce must come before aesthetic or moral arguments, such as the intrinsicvalue of biodiversity, the possible foregone economic and practical uses of lost species must berecognized as important and irrevocable.


animals that depend on them. Finally, emissions from fuel combustion or other energy-related activities(e.g. releases of radioactivity from nuclear plants) may decrease biodiversity by directly or indirectlyadding to the stress on selected plants and animals. Acid deposition can threaten acid-sensitive plants,while encouraging growth of other acid-loving ones.

2.3 Regional Issues

The distinction between global and regional issues is obviously difficult to precisely define. Forinstance, land degradation, the first of the regional issues discussed below, is intimately related toreductions in biodiversity, a global issue in our taxonomy.

In this section, we present overviews of a group of environmental issues -- land and water use anddegradation, ocean contamination, mobilization of toxic contaminants, acid deposition, and radioactive

BOX 2.3:ENERGY SOURCES WITH POTENTIAL IMPACTS ON BIODIVERSITY

TECHNOLOGY MECHANISM OF IMPACT

Biomass Plantations Conversion of natural land to managed monoculture (such as Eucalyptusplantations or energy crops) can eliminate or fragment habitats. Conversely,if degraded land is used, and a diversity of tree species and ages aremaintained, biodiversity can be enhanced.

Traditional BiomassHarvesting

Disturbance of natural ecosystems where fuelwood harvesting and charcoalproduction activities encroach upon previously pristine woodlands andforests.

Hydropower Projects Flooding of areas behind dams destroys existing habitats. Building andoperation of dams can result in soil loss and siltation of rivers and estuaries,disrupt fish populations, and deprive downstream ecosystems of nutrientflow.

Fossil Fuel Explorationand Extraction

Exploration for and extraction of fuels can result in large-scale loss ofhabitats as soils and vegetation are stripped away to provide access to thefuel resources. Emissions from the operation of fuel production facilitiessuch as contaminated drainage waters from mines and spills from test andoperating oil wells also have the potential to reduce biodiversity.

Fuel Combustion Pollutants emitted during fuel combustion can disrupt habitats through manymechanisms, including climate change, acid deposition, local air pollution,and release of toxic compounds and metals.

Transportation andTransmission Projects

Construction of electric transmission lines, pipelines, roads, and other energytransport modes can fragment animal and plant habitats, import pollution,and lead to increase human settlement, which in turn can place greaterstress on plants and animals in the area.

Central-station solarplants

Land must be cleared and kept clear of larger plants in order to install andmaintain solar collectors. Collectors also keep sunlight from reaching theground, preventing or reducing plant growth.


waste -- that are often characterized by regional impacts occurring over a wide area, potentially at a greatdistance from the location where the responsible energy technologies are used.

Land and Water Use and Degradation

Land degradation -- soil erosion, deforestation, desertification, and so on -- is arguably the singlemost visible and immediate environmental concern in many developing countries. It has many forms andmany causes. It is also a somewhat controversial issue. Where some may view forest clearing as habitat-threatening, climate-altering deforestation, others may see it as an opportunity to exploit natural resourcesor expand agricultural productivity. In addition, the question of reversibility is an essential one. Landcleared for charcoal production and/or other purposes may or may not regenerate; "deforestation" may ormay not be permanent, and soil may or may not be degraded in the process. As described below, localfactors such as post-harvest land management and soil and climate characteristics are importantdeterminants of the fate of cleared land.

A recent UNEP study provides what is perhaps the most extensive global survey and assessment oftrends and causes of soil degradation. (Oldeman, van Engelen, and Pulles, 1990) Soil degradation isdefined in that study as "a process that describes human-induced phenomena which lower the currentand/or future capacity of the soil to support human life". (L.R. Oldeman, as cited in World ResourcesInstitute, 1992, p.112-3) Although we might use a broader definition for land degradation, one thatincludes reduced ability to support healthy ecosystems and reduced aesthetic value, the results of the UNEPstudy provide an interesting comparison across causes and regions. The study found that the largest singleglobal cause of soil degradation to be overgrazing, accounting for 35% of the global total, as shown inTable 2.3 below. Woodfuel overexploitation, on the other hand, is estimated to account for only 7% ofglobal degraded area, with greater relative importance in Africa (13%) and Central America (18%) than inother regions.

Table 2.3:Levels and Causes of Soil Degradation by Region

Total DegradedArea (Million ha)[% of Vegetated

Area]

WoodfuelOverexploitation

LandConversion& Logging

Overgrazing AgriculturalActivity

Industrial-ization

Africa 494 [22%] 13% 14% 49% 24% --Europe 219 [23%] -- 38% 23% 29% 9%Asia 747 [20%] 6% 40% 26% 27% --Oceania 103 [13%] -- 12% 80% 8% --North America 96 [5%] -- 4% 30% 66% --Central America 63 [25%] 18% 22% 15% 45% --South America 243 [14%] 5% 41% 28% 26% --World 1964 [17%] 7% 30% 35% 28% 1%

Source: Oldeman, van Engelen, and Pulles, 1990 as cited in World Resources Institute, 1992.

These data concur with the general understanding that woodfuel use is only one, often lessimportant, of many factors that can result in soil and/or land degradation. Similarly, the collection ofsubsistence levels of woodfuels is only one of several processes that contribute to the clearing of forestedlands. Commercial logging and land clearing for agricultural expansion are often the major contributors todeforestation. Furthermore, despite indicative aggregate figures, there are no generalizable results orrelationships that can be used to estimate the role of woodfuel harvesting on land and soil degradation, or


on deforestation. While woodfuel scarcity and land degradation problems are often of regional importance,they tend to be dependent on highly localized conditions.

As noted above, another major potential contributor to water and land degradation is waterimpoundment for hydroelectric and other purposes. High-head hydroelectric dams can flood large areas,forcing resettlement of local human populations, and displacing or killing animal and plant populations.

By their nature, hydroelectric dams also change the timing and magnitude of water flows. In largerrivers, this can affect downstream and upstream fish populations, the availability of water to sustainaquatic ecosystems, agriculture, and mariculture (e.g. shellfish harvesting), to recharge ground water, andto provide for domestic needs. In addition to changing the quantity of water available, the quality of watercan also suffer. Lower water flows can cause an increase in the concentrations of salts, toxic metals,fertilizers, pesticides, and herbicides. “Hydro” projects can also change the amount and timing of sedimentflow in rivers, potentially affecting the fertility of farmlands in downstream areas and/or changing floodpatterns. Operation of hydroelectric facilities sometimes involves rapid fluctuation of the amount of waterreleased, as the demands for electricity by consumers change over a day, week, or year. These fluctuationscan cause rapid changes in water levels downstream and in the reservoir behind the dam, changes that aredisruptive to ecosystems and human activities alike. The large impoundments (lakes) behind hydroelectricdams also may change regional weather patterns by altering the extent, timing and location of evaporationof water. Box 2.4 summarizes these and other impacts of the construction and operation of hydroelectricfacilities.

Large-scale use of biomass energy can also have regional impacts on water and land use. If largetracts of forest lands are cleared to plant fuel crops or for direct use as fuel, erosion could result, affectingecosystems and human activities downstream. Intensive irrigation of biomass crops may deplete surface-and ground-waters, leaving less water of potentially poorer quality for areas downstream. This may evenhappen in the absence of vegetation, if biomass crops that are particularly adept at tapping the water tablereplace natural vegetation that transpires21 less water to the atmosphere. Intensive use of fertilizers,herbicides and pesticides in biomass production can also affect downstream water quality as thesechemicals are carried away with runoff or eroded soil, or leach into ground water.

Other energy resources and technologies also have land and water use impacts. Oil and gasproduction sites can disturb sensitive ecosystems, consume water resources, and produce drilling wastesand localized oil spills that can contaminate surface and ground waters. (See section on OceanContamination below.) Coal mining, particularly surface or strip mining, can degrade large areas.Electric production facilities, particularly those using wind and solar resources, can also require significantland area.

Land use comparisons among energy options should distinguish between land that is “occupied”and the land that is actually “used” or devoted solely to energy production. In the case of wind energy“farms”, and some solar and biomass facilities, a large land area may be occupied relatively sparsely withwind turbines or solar panels and the remaining area is available for other purposes such as grazing

21 "Transpiration" or "Evapotranspiration" is the process whereby growing plants use water for growth, and in so doing, movewater from the soil to the air. Water taken up by the roots of plants passes through the plant stems and branches andevaporates from leaf surfaces. Different types of plants transpire different amounts of water for each kilogram of biomassproduced.


BOX 2.4: POTENTIAL ENVIRONMENTAL AND SOCIAL IMPACTS OF

HYDROELECTRIC POWER DEVELOPMENT AND OPERATION

SOURCE OF IMPACT DESCRIPTION

Plant Construction Direct environmental impacts include those caused by water diversion,drilling, slope alteration, reservoir preparation, and building of infrastructure(roads, dwellings, sanitary facilities) for the project workforce. IndirectImpacts include the impacts on the surrounding area of an often large groupof construction workers, their families, and others, including deforestation,the emergence of shanty towns, sanitation problems, and the exacerbation ofurban and rural poverty.

Land Inundation andReservoir Filling

As noted in the text, inundation of reservoir areas displaces localpopulations, especially as people tend more often to live in rural valleyswhere water and rich soil are often found. Resettlement of populations maybe disruptive to the way of life of those being resettled and to existingresidents of the resettlement area. Acquiring land for the reservoir andproviding for resettlement can also be significant economic concerns. Theloss of floodplains removes a crucial area of interaction between riverine andterrestrial ecosystems. Filling or emptying reservoirs has been known tocause or increase seismic activity (earthquakes) in the region of the hydrofacility. If biomass (especially small plants, leaves, and twigs) are notremoved from the reservoir area before filling, its decomposition can affectwater quality.

Changes in WaterQuality, Sedimentation,and Ecosystems

The existence of the impoundment changes the flow of oxygen, chemicalnutrients, and soil particles normally carried downstream by the river. Watertemperature can also be affected. Ecosystem changes caused by damsinclude their impact as barriers to fish migration, killing of fish that passthrough hydroelectric turbines, and the loss of fish species that must haveflowing water to survive. These changes affect natural ecosystems andagricultural areas downstream. Disturbance of ecosystems may createbreeding grounds for water-borne pathogens. In the reservoir itself, lack ofmixing can create stratified (layered) areas of water, including layers withlittle or no oxygen where biomass (including biomass remaining in thereservoir at the time of filling) decomposes to methane, a greenhouse gas.Anoxic (no oxygen) conditions also may help to release heavy metals andother pollutants brought by the river from upstream areas. Sediment carriedby the river when free-flowing builds up in the reservoir, often reducing thewater and electricity generating capacity of the plant.

Public Health Major human diseases associated with water resource development includemalaria, shistosomiasis, and lymphatic filariasis, which together afflict overhalf a billion people in developing countries. Reservoirs provide breedinggrounds for the organisms (such as mosquitoes) that act as hosts to thesepathogens.

Source: J.R. Moreira and A.D. Poole, Chapter 2, “Hydropower and Its Constraints” in Johansson et al,1993.


or natural habitat (as in well-designed biomass plantations). Figure 2.4 below provides a comparison ofthe land occupied and used for coal, wind, and solar electricity production in California. When the landused for resource extraction (e.g. coal mining) is included, and the land used is distinguished from landoccupied, the land use for coal and solar electricity appear comparable, while wind is lower.

2.3.1

2.3.2 Acid Deposition

Acid deposition results when nitrogen and sulfur oxides ("NOx" and "SOx") react in the atmospherewith oxygen and water droplets to form nitric and sulfuric acids (HNO3 and H2SO4). As the water dropletscondense, they fall as rain, snow, or fog, hence the common name "Acid Rain". We should note that whileacid rain is the most frequently discussed pathway for these compounds to return to earth, nitrates andsulfate ions23 (NO3

- and SO4

2-) also can combine with positive ions or adhere to the surface of particles inthe atmosphere, sometimes falling to earth in a dry form (“dry deposition”). SOx and NOx can also directlyadhere to soil or plant surfaces, eventually reacting with water and oxygen to form acids. As aconsequence, the terms "Acid Rain" and "Acid Precipitation" are somewhat incomplete--though morecommon -- terms for the broader phenomenon of acid deposition, the term we use most frequently here.

The standard measure of acidity is the pH scale. pH is equal to the base-10 logarithm of theconcentration of hydrogen ions (H+), and is given on a scale of 0 to 14, with low pHs being indicative of

22 Based on Gipe, 1991, p.764. For comparison, Pasqualetti and Muller, 1984, report a land-use requirement of 7-13 acres (3-5 hectares) per MW for mid-Western US opencast coal mines.23 Ions are electrically charged elements of molecules. Negatively charged elements or molecules (like the sulfate and nitrateions) are called anions, and positively charged entities are called cations. Anions and cations combine to neutralize each otherscharge and yield salts, such as the common table salt, NaCl, which is made up of a positively-charged sodium atom (Na+) and anegatively-charge chloride ion (Cl-).

Figure 2.4:Land Used for Electricity Generation in California22

SolarThermal(parabolic

trough)

Coal(includesmining)

SolarThermal(central

receiver)

Solar PV(dense area)

Wind Solar PV(desert)

0

2

4

6

8

10

12

hec

tare

s/M

W

Area Occupied Area Used


highly acid solutions (e.g. vinegar), and high pH's being indicative of highly alkaline (or basic) solutions(such as lye). Neutral pH, the pH of distilled water, is 7.0, and physiological pHs, that is, the pHs mostcommonly found in plant and animal cells, are typically (but not always) between 6 and 8. In theatmosphere, water reacts with CO2 to form carbonic acid (H2CO3), a weak acid, and as a consequence thepH of rain and snow in the absence of all pollutants would be about 5.6. Precipitation with a pH lowerthan this level is considered acid precipitation. Remember that because pH is measured on a logarithmicscale, small changes in pH can mean relatively large changes in acidity. Precipitation with a pH of 4, forexample, is 10 times as acid as rain of pH 5.

The effects of acid rain vary considerably with the vegetation, soil types, and weather conditions ina given area. Under some conditions, the addition of sulfate and nitrate to the soil helps replace lostnutrients, and aids plant growth. In other instances, however, acid deposition can cause lakes and streamsto become acid, damage trees and other plants, damage man-made structures, and help to mobilize toxiccompounds naturally present in soil and rocks. Acid rain has been implicated in the death of fish and otheraquatic life in otherwise pristine lakes in the northeast United States, southeast Canada, and Scandinavia.Lakes and soils with minimal buffering capacity (the ability to maintain pH in response to the addition ofacids), such as many of those found in these areas, are particularly susceptible to acid rain. The loweredpHs in some North American and Scandinavian lakes has resulted in loss of and/or shifts in speciescomposition of the phytoplankton (including algae) that are the base of the aquatic food chain, and damage-- direct and indirect -- to aquatic invertebrates (e.g. insects and small crustaceans), amphibians, and fish.The gradual die-off of forests in Germany, Sweden, and other areas has also been attributed to the effectsof acid deposition. Plants are affected by acid rain in several ways, including direct erosion of cellularstructures in leaves, interference with cell processes and the uptake of gases (including CO2) from theatmosphere, alteration of soil chemistry and the activity of bacteria and other microorganisms in soil,interference with plant reproduction, and weakening of plants' susceptibility to disease and pests.Buildings and other structures, including many ancient cultural landmarks, are being degraded by acid rain,particularly those structures made of minerals, such as limestone, that are more soluble in more acidicsolutions. In soils with limited buffering capacity, the acidified water flowing through the soil can dissolveand mobilize potentially toxic minerals, such as aluminum, leading to elevated concentrations in streamsand lakes. A nutrient in small quantities, aluminum can become toxic to fish and other organisms at thehigher concentrations found in acidified watersheds24.

While natural sources account for a significant, though uncertain, fraction of the atmosphericsulfur and nitrogen oxides that are the precursors of acid deposition, human sources appear to be the majorcause of recent declining trends in the pH of rainfall. While some industrial sources of emissions,particularly the smelting of metal, are important sources of sulfur oxides, the energy sector accounts for alarge fraction of these emissions. Sulfur oxides are produced during combustion of coal, which containsvarying amounts (about 0.5 to 5 or more percent) of sulfur, and during combustion of fuel oil, particularlythe heavier grades. These fuels are most commonly used in large industrial facilities and in electric powergeneration. Nitrogen oxides are produced at varying rates by all types of fossil and biomass fuelcombustion; the nitrogen in the NOx produced during combustion is derived both from nitrogen in the fueland from the molecular nitrogen (N2) that makes up nearly four-fifths of the air we breathe. Gasoline-powered autos and trucks are major emitters of NOx.

Though acid deposition can be a local phenomenon, particularly in urban areas and in areas near alarge point source of emissions, the extent to which acid gases are carried by prevailing weather patternsmakes acid rain a truly regional issue, one that frequently crosses national boundaries. For example, many 24 A watershed is the area around a body of water that catches the rain and snow that feed into it.


of the acidified lakes in Eastern North America are hundreds of kilometers from major sources ofemissions. Likewise, emissions from as far away as the United Kingdom have contributed to acid rain andforest decline in Scandinavia. Automobile use in Southern California is probably a major contributor tolow-pH rain and snow in the Colorado Rockies, well over 1000 kilometers away.

2.3.3 Mobilization of Toxic Contaminants & Bioconcentration

Emissions to the air and water from energy technologies can also lead to the mobilization of toxiccontaminants that, in turn, can have far-reaching impacts. Once introduced into the environment, a toxicmaterial can be transported by a variety of physical means (for example, wind, groundwater flow) tosensitive organisms, or can reach those organisms less directly through bioconcentration in the food chain.Table 2.4 presents some of the pollutants that can be mobilized by human activities, and provides anindication of how human activities contribute to the level of those pollutants in the biosphere.

One example is the lead used in a performance-enhancing additive in automotive fuels. When"leaded" fuels are burned, the lead that goes out the tailpipe (typically as a compound called tetraethyl lead,which is more toxic than elemental lead metal) can end up, blown by prevailing winds or carried in rivers,in the ocean, where it may have several effects. Since lead (and other toxic metals, such as mercury andcadmium, which are emitted by energy technologies such as coal combustion and oil refining) isconcentrated in the ocean food chain, the danger of chronic or acute poisoning is increased for the largeranimals in the chain (including humans). As of the mid-1970's, it was estimated that the average globallead concentration in the open ocean had increased several-fold since the introduction of leaded gasolines(Ehrlich, Ehrlich, and Holdren, 1977).

The food chain denotes the linkage between predators and prey, producers and consumers. Eachfood chain is founded on a plant or collection of plants called the "primary producer(s)". The primaryproducer takes in solar energy, carbon dioxide, water, and nutrients, and produces plant biomass. Theseplants are then eaten by animals or microbes, called the primary consumers, which may be eaten by otheranimals, and so on up to the "top carnivore", the animal that is at the top of the food chain. Some naturalor managed food chains may be very short, e.g. grass is eaten by cattle which are eaten by people. Othersmay be much longer, as in the ocean where phytoplankton (algae and other microscopic plants that floatfree near the surface waters) are eaten by zooplankton (tiny animals that float along with thephytoplankton), which are in turn eaten by tiny fish, which are eaten by larger fish and so on up to a topcarnivore such as a shark or human. No matter what the length of the food chain, conservation of energydictates that there is less biomass -- actually on the order of ten-fold less -- at each level of the chain. Thisreduction in biomass, which can be several orders of magnitude for a longer food chain (i.e., it might take10 tonnes of algae to ultimately produce 1 kg of shark) is important because some pollutants are retained inthe bodies of the organisms that take them in, then passed on to the organisms higher up the food chain.Thus a compound that is present at level too low to cause biological problems, say one part per million(ppm) in a primary producer, may be a thousand-fold more concentrated in a top carnivore, and may at thatlevel be quite toxic.


Table 2.4:Human Disruption and Mobilization of Pollutants: Global Estimates

(Adapted from Holdren, 1990)

AffectedQuantity

NaturalBaseline

HumanDisruption Index Sources of Human Disruption

Lead (Pb) Flow 25,000tons/year

15 60% fossil fuel combustion40% metal processing, manufacturing, refuse burning

Mercury (Hg)Flow

25,000tons/year

.7 20% fossil fuel combustion80% metal processing, manufacturing, refuse burning

Cadmium (Cd)Flow

1,000tons/year

8 10% fossil fuel combustion70% metal processing, manufacturing, refuse burning20% traditional fuel combustion; agricultural burning

Oil Flow toOceans

250,000tons/year

13 50% marine oil transport (spills, routine operation)40% municipal and industrial wastes and runoff10% atmospheric emissions

Sulfur Dioxide(SO2) Flow

160,000tons/year

> 1 90% fossil fuel combustion10% metal smelting, sulfuric acid production, etc.

CarbonMonoxide (CO)Flow

500 milliontons/year

1.4 30% fossil fuel combustion25% oxidation of anthropogenic methane25% forest clearing; 15% savanna burning10% from wood burning, other HC oxidation

Nitrogen Oxide(NOx) Flow

40 milliontons N/year

1 75% fossil fuel combustion25% fertilizers, biomass burning, industrial processes

Particle Flow 500,000tons/year

.6 35% fossil fuel combustion10% traditional fuel combustion40% agricultural burning, wheat handling15% smelting, land clearing, refuse burning

Cumulative SoilDegradation

notapplicable

17% of globalvegetated area

woodfuel harvesting, overgrazing

Sources: Adapted from Holdren 1990; Additional Data from UNEP, 1989 and Katsouros, 1992.

The classic example of a bioconcentrated toxin is DDT25, which was used extensively as apesticide in the 1950's and 1960's. This chemical was found at very high concentrations in the blood andeggs of large birds, including the brown pelican (Ehrlich et al, 1977) and other top carnivores, oftencausing failure in reproduction and/or other effects. In the energy sector, other potentially bioconcentratedtoxins include pesticides and herbicides sometimes used on biomass crops or to maintain road, power line,or pipeline right-of-ways, and compounds or metals that are produced, discarded and/or released duringpetroleum refining, oil and gas exploration, and geothermal power generation.

2.3.4 Ocean Contamination

The most visible and prevalent example of direct spillage of energy products into oceans is that of"oil spills". Crude oil and refined products spill during routine operation of offshore oil rigs, from oiltanker filling and off-loading operations, during the cleaning of tankers, as spillage from other (non-tanker)

25 DDT is the chlorinated hydrocarbon dichlorodiphenyl trichloroethane.


ships that use petroleum fuels, and as a result of leakage from undersea pipelines, as well as during lessfrequent but better-publicized oil tanker accidents and "blowouts26" at offshore oil platforms.

These spills are toxic to many forms of marine life, as well as fouling beaches and affecting otherecosystems and man-made installations along the shoreline. Oil floating on the ocean’s surface can coatmarine birds, making them unable to fly, reducing the insulating properties of their feathers (so that theycan no longer stay warm), and usually eventually killing them. Birds can ingest oil when they try andpreen it out of their feathers, and developing embryos inside eggs can be killed if oil gets on the egg. Oilspills also disrupt the food chain by killing phytoplankton and zooplankton27 at or near the oceans surface.Toxic and carcinogenic (cancer-causing) compounds in oil products can cause death and illness in theseorganisms or they can become bioconcentrated (as discussed above) in the food chain. Heavier oil products,and the heavier fraction of crude oils, sink to the bottom, where they can coat shellfish beds, makingshellfish and other invertebrates inedible. Damage from oil spills may persist for many years, ascompounds contained in oils can remain both in the bodies of organisms and in marine sediments. Oilspills can be spread rapidly by tides, currents, and winds, making them a regional as well as local threat.

Table 2.5:Sources of Petroleum Hydrocarbons in the Marine Environment

(Millions of Tonnes Annually)Source Probable Range Best EstimateNatural Sources 0.025 - 2.5 0.25Atmospheric Pollution 0.05 - 0.5 0.3Marine Transportation 1.00 - 2.60 1.45Offshore Petroleum Production 0.04 - 0.06 0.05Municipal and Industrial Wastes and Runoff 0.585 - 3.21 1.18Total 1.7 - 8.8 3.2

Source: M.H. Katsouros, Chapter 5 in Hollander, 1992.

Several other ocean/sea environmental impacts are related to existing or possible future energydevelopment activities. By changing the timing and amount of fresh water and sediment flows that reachthe ocean, hydroelectric projects on major rivers can affect ocean ecosystems. Much of the totalproduction of plant and animal biomass in the ocean takes place near land, and many animals live at leastpart of their lives in or near fresh water or in the estuaries where fresh water from rivers mixes with the saltwaters of the oceans. Changing the timing and amount of fresh water can change environments at theocean's edge sufficiently as to affect the breeding and growth of the organisms there, which can have animpact on the marine ecosystem in the entire region. Too little sediment flow can reduce the fertility of theocean by reducing the input of needed inputs from the land. Too much sediment flow, on the other hand,can increase the turbidity (or murkiness) of water, resulting in reduced photosynthesis and productivity.Excess sediments can also bury key marine habitats, such as shellfish beds.

26 A blowout occurs when the wellhead where the flow of oil from a well is controlled fails catastrophically, allowing oil,driven by high gas and/or liquid pressures in the well, to flow out of the well and into the surrounding environment.27 Phytoplankton is a name used to denote the class of microscopic-to-barely-visible aquatic plants that are the base of much ofthe ocean's food chain. Phytoplankton include marine algae, diatoms, and other photosynthetic organisms. Zooplankton arethe micrometer-to-millimeter-size animals that, like the phytoplankton they feed on, float along near the surface of the ocean.Zooplankton include the larval and juvenile (young) stages of a number of commercially and biologically important organisms,such as crustaceans (e.g. shrimp and crab) and mollusks (shellfish). Zooplankton in turn serve as food for small fish and otheranimals.


Several proposed ways of capturing energy from the oceans, typically as electric power, have beendiscussed and investigated in recent decades. These options, including ocean thermal energy conversion(OTEC), and generating electricity from tidal power, wave power, and ocean currents, may have regionalas well as local impacts. OTEC, in which large quantities of cold deep ocean water are brought to thesurface (power is generated by taking advantage of the difference in temperature between this water andwarmer surface waters) increases the supply of nutrients to marine ecosystems near the surface, which canchange the distribution of marine biomass in the region. Tidal power stations (in their simplest form)employ a dam that can be open and shut across the mouth of a bay. Sea water admitted at high tide isreleased through a turbine at low tide to generate electricity. Their operation changes the patterns of watersupply to the bay and surrounding waters, potentially with many of the same impacts on marine life asland-based hydroelectric systems have on freshwater ecosystems. Systems to capture energy from wavesor ocean currents are unlikely to have regional impacts if deployed on a small scale, but could potentiallyinfluence fish and marine mammal migration patterns, shipping, or the circulation of ocean currents if theyare used extensively. Wide use of any of these ocean-energy technologies is unlikely within the next fewdecades.

2.3.5 Radioactivity and Radioactive Wastes

Nuclear energy, from fission, and perhaps in the future from fusion28, has tremendous theoreticalpotential as an energy source, but social, economic, institutional, and environmental concerns have slowedits development significantly over the past decade. As of 1989, twenty-three countries used nuclear fissionto generate electricity, the combined amount accounting for slightly more than two percent of total globalcommercial energy production (World Resources Institute, 1992; Table 21.1). To date, with the obviousexceptions of nuclear weapon detonations and the accident at the Chernobyl power plant in April 1986,exposures of the public and environment to radioactive pollution have been limited. Nevertheless, as aresult of Chernobyl and other near catastrophes such as the 1979 accident at Three Mile Island in theUnited States, concerns over the safe operation of nuclear power plants persist29. Critics also contend thatwaste storage and weapons proliferation problems have not been, and perhaps cannot be, adequatelyaddressed. On the other hand, advocates promote nuclear power as a clean energy choice for the future.

Radioactive materials undergo spontaneous transformations of their atomic nuclei. The number oftransformations occurring per unit of time is a measure of radioactivity. The common unit for radioactivityis the curie (Ci), representing approximately 37 billion nuclear transformations per second. Nucleiundergoing transformations emit energy (radiation) in the form of alpha particles, beta particles, gammarays, or individual neutrons. Alpha particles are massive and unable to penetrate human skin. Thereforethey are dangerous -- and are capable of causing great damage -- only if they are emitted inside the humanbody, after ingestion or inhalation. Plutonium-239, for example, is a powerful emitter of alpha particles.Beta particles are much lighter and more capable of penetrating barriers. Like alpha particles, they aremost harmful if emitted internally, but externally-emitted beta particles can also be dangerous. Gammarays and neutrons are capable of traveling hundreds of meters and penetrating solid walls.

Radioactivity and the effects of ionizing radiation have been so well studied that radiation, somesuggest (Ehrlich, Ehrlich and Holdren 1977), may be the best understood of the major pollutant categories.

28 Fission refers to the process in which the nuclei of large atoms, e.g. Uranium, are split to form smaller atoms, liberatingenergy (fast-moving particles and electromagnetic radiation) in the process. Fusion occurs when the nuclei of smaller atoms,such as hydrogen, are forced together to form larger atoms, which also releases energy.29For a description of the events, and potential impacts of the accidents at Three Mile Island and Chernobyl see Chapter 6,"Nuclear Power" by Hohenemser, Goble and Slovic, in Hollander (1992).


The available information on radiation effects may still, however, be inadequate, since significantuncertainties remain.

Exposure to radioactivity is typically measured in rems or sieverts (Sv)30. Rems equal rads, ameasure of the amount of energy deposited per unit mass of absorbing material, multiplied by a factoraccounting for the effectiveness of the deposited energy in doing damage. Doses of radiation in the rangeof 100 rems to more than 1000 rems could be experienced as the result of the detonation of a nuclearweapon, or during a catastrophic accident at a nuclear power station or fuel reprocessing plant. Theselevels of exposure are likely to lead to acute illness or death within hours to weeks after the exposure. Thelethal dose of radiation expected to kill 50 percent of the exposed population within sixty days of theexposure is generally assumed to be 250 to 450 rem. Doses from naturally-occurring background sourcesof radiation in the United States range from 100 to 250 millirems/person/year31. Common exposurestandards are 5 rems/year whole body exposure for workers in the nuclear industry, 500 millirem/year toindividual members of the general public, and 170 millirem/year as an average exposure for largepopulations. Statistical analyses have shown links between increased, non-acute radiation exposures andincreased cancer rates, genetic defects, prenatal problems, fertility problems, and cataracts of the eye(Doull et al, 1980). The National Academy of Sciences estimated that increasing the background exposurelevel in the United States by 100 millirem would result in 3000 to 4000 additional cancer deaths per yearand an equal number of additional non-fatal cancers (Ehrlich, Ehrlich, Holdren 1977).

Exposures to radioactivity from the routine operation of nuclear power stations are relativelyminor. Releases of tritium and krypton gas during the reprocessing of nuclear fuels are the largest routineemission, and these represent only small additions to natural background radiation levels. More seriousenvironmental questions are related to the sustained management of nuclear wastes, the possibleproliferation of nuclear weapons, and the prevention of catastrophic radiation releases from reactors andreprocessing plants. The inventory of a large nuclear reactor's long lived radioactivity is more than 1,000times that of the atom bomb dropped on Hiroshima. Radioactive wastes must be safely managed for longperiods of time, tens of thousands of years for materials with long half-lives. Creating a hazard that is athreat so far into the future poses an ethical question of inter-generational responsibility. No proposals forthe long-term disposal of high level nuclear wastes have been able to overcome political and technicalobjections, and the question of what to do with nuclear wastes remains unresolved.

Another consideration in weighing the attributes and problems of nuclear energy is the potential for nuclearweapons proliferation, that is, the potential for nuclear materials from power reactors to be diverted fornon-peaceful uses. All fission reactors produce materials suitable for making nuclear weapons. Theamount of fissile material32 required to make a weapon depends upon the material's critical mass. Forplutonium-239 the critical mass lies in the range of 4 to 8 kilograms, and for uranium-235 the high end ofthe range is only 25 kilograms. (Ehrlich, Ehrlich, and Holdren, 1977). Even the most meticulous nationalor international accounting and security measures cannot insure that amounts sufficient for weaponsbuilding do not go missing. Even smaller amounts of highly toxic radioactive materials such as plutonium-239 could be used to, for example, poison the water supply of a major city.

The promise of nuclear energy has been offset by the specter of potential large-scale environmentaldisasters. Large-scale radiation releases, eventually resulting in tens, even hundreds of thousands ofdeaths, widespread property loss and ecosystem contamination are improbable, but not impossible. More

30 1 rem = 0.01 Sv.31 Recall that one millirem is one thousandth of a rem.32 Material that can undergo fission reactions.


than with other energy technologies, assessing the environmental impacts of nuclear energy hinges uponestimating the probabilities and acceptability of rare and catastrophic events (see under Accidents below).As a consequence, debate on this issue is likely to continue.

2.4 Local Issues

Some or all of the issues discussed above can, it could be reasonably argued, be considered local aswell as regional in scale, depending on the magnitude of the specific disturbance caused by the energysystem evaluated. What follows is a discussion of environmental issues whose effects are mostly on thelocal level, that is, within the area where the fuel-consuming device or energy supply technology is located.

2.4.1 Urban Air Pollution

Power plants that burn fossil or biomass fuels emit pollutants that, if not properly controlled, cancause or exacerbate health (especially respiratory) and aesthetic impacts in the locale of the plant. Thesepollutants include particulate emissions, , carbon monoxide, hydrocarbons, and others. Emissions varysignificantly with the type of power plant and the fuel used. Geothermal plants can emit hydrogen sulfide,a noxious and, in high enough concentrations, toxic gas.

The production, distribution and combustion of fossil fuels -- particularly combustion in motorvehicles -- emits carbon monoxide, NOx, SOx, hydrocarbons, and other compounds In high enoughconcentrations, these molecules can react with each other, additional compounds already present in theatmosphere, and sunlight to yield photochemical smog. If sufficiently severe, smog can be a hazard tohuman health, livestock, and natural ecosystems, as well as damaging buildings or other structures(Ehrlich, Ehrlich, and Holdren, 1977; Freedman, 1989; USEPA, 1985).

Compounds containing lead have until recently been routinely added to motor fuels to enhanceengine performance. When these fuels are burned, lead is emitted, and can be taken up by both plants andanimals, including humans, from the air or in food and water. Lead poisoning -- which can impair thefunction of the muscular, brain, circulatory, and digestive systems -- results when level of lead in the bloodrise above a threshold level, but lower levels of lead may also cause physiological problems. The processof removing lead from motor fuels is underway, but not yet complete (Ehrlich, Ehrlich, and Holdren, 1977).

Combustion of wood in wood stoves releases particulate matter, carbon monoxide, hydrocarbons,and other pollutants. At most times of the year this does not cause serious problems in the rural areaswhere wood is typically burned (especially in developed countries), but under atmospheric conditionsknown as temperature inversions, which occur relatively frequently in the winter in some temperate locales,wood smoke can be retained within small valleys, allowing pollutants to build up to levels that canexacerbate or cause respiratory problems (Ehrlich, Ehrlich, and Holdren, 1977; California Air ResourcesBoard, 1990).

2.4.2 Indoor Air Pollution

While the concept of air pollution is often associated with smokestacks, automobiles, and smoggyurban environments, there is evidence to suggest that indoor air pollution may also have significant healthimpacts. Indoor fuel combustion can create elevated concentrations of carbon monoxide, carbon dioxide,oxides of sulfur and nitrogen, particulate matter and polycyclic aromatic hydrocarbons. Globally, biomassfuels used for cooking, lighting and heating are the most common source for these emissions. Over half of


the world's population depends upon wood fuels, crop residues, or dung to meet their daily cooking energyrequirements (OTA, 1991, p.51).

The type and level of emissions depend on several factors: fuel type, the design of the end-usedevice, and the nature of the combustion. Smith (1987) notes that while biomass fuels can be burned withminimal smoke production and with the release of few toxic contaminants, under normal operatingconditions household size stoves emit a wide range of the pollutants listed above. The resulting indoorpollutant concentrations and human exposures depend on additional factors such as dwelling architecture,indoor/outdoor air exchange rate, and the duration of an individual's exposure to the emission source. Dueto the extensive use of biomass fuels and the close proximity of human "receptors" -- particularly womenand children -- to the emission sources, the resulting pollutant "doses" can be quite high. Smith (1987)calculates that in India, a ton of particulates emitted by household biomass stoves may produce over 500times the combined human dose of a ton of particulates emitted by a coal-fired power plant.

In general, biomass fuel use under enclosed conditions can be expected to result in high emissionsof and human exposures to CO, particulates and hydrocarbons, and there is empirical evidence to validatethis expectation (Ellegard and Egneus 1992; Smith 1987). However, as illustrated in Table 2.5, theevidence of direct relationships between increased exposures and negative health impacts is moreambiguous.

Table 2.6: Direct Evidence of Health Impacts of Domestic Biofuel Smoke Exposure

(from Smith, 1987)

------------------------------------- Study Location-----------------------------------

Health Effect:Africa Papua New

GuineaIndia China Nepal U.S./U.K.

Chronic Obstructive LungDisease Q- A+/SQ± A+/SQ± SQ+/Q+ A+/AQ-Cancer A+ A+/Q- Acute RespiratoryInfection

A+/Q- A+/AQ- A+ AQ+/Q+ Q±

Low Birth Weight,Cardiovascular Disease Notes: + = Positive evidence, - = negative evidence, A = Anecdotal evidence, Q = Quantitative evidence,SQ = Semiquantitative EvidenceSources: Smith (1987; p.227), Ellegard and Egneus (1992).

Much of the evidence on the health effects of indoor air pollution is anecdotal or conflicting,suggesting the need for further research. For two potentially important health categories, birth weight andcardiovascular disease, no studies are available. The conflicting evidence is not surprising since studies ofdirect health impacts must account for a number of factors, such as the delayed effects of chronicexposures and their interaction with other health variables such as smoking, and diet.

In countries where biomass fuels are not widely used, indoor air pollution may still be a concern.Emissions sources include improperly vented propane or natural gas cooking and heating appliances,household chemicals, cigarettes, and radioactive Radon gas. Generally, the most effective approach tocontrolling these hazards is to identify and minimize, or eliminate, the pollutant source. In the case of very


tightly sealed houses, where adequate source control is not possible, the installation of air to air heatexchangers can provide adequate ventilation while minimizing heat loss.

2.4.3 Surface and Ground Water Pollution

Water is an essential resource for all life, and yet freshwater resources are under intense andincreasing stress. Water is continuously in demand, and is required for agriculture, industry, and domesticuse. Often, at the same time, waterways serve as receptacles for the waste products of society. Thevulnerability of civilizations to water stress is perhaps partially masked by the hydrologic cycle, whichoperates at a global scale to replenish and renew freshwater stores and sources. Even so, it is increasinglyapparent that the stewardship of water resources is not an item to be considered only in cases of acuteimbalance and distress, but that the issue deserves general and consistent attention. In comparison to otherstresses on freshwater resources -- including water use for irrigation, pollution via agricultural runoff, andpollution from municipal sewage -- energy-related water use and pollution are often relatively minor, butthe impacts are far from negligible.

Water pollution can be classified into at least seven major categories:

1) Excess nutrients from sewage and soil erosion, which can cause algae blooms that eventuallydeplete the oxygen content of the water;

2) Pathogens from sewage that spread disease;3) Heavy metals and synthetic organic compounds from industry, mining, and agriculture;4) Thermal pollution, which can alter the chemistry and structure of aquatic ecosystems;5) Acidification;6) Suspended and Dissolved Solids; and7) Radioactive pollution.

Energy production and consumption are most closely associated with the last five types ofemissions. The mechanics and consequences of acidification and radioactive pollution were discussedpreviously in the section on Regional Environmental Issues.

At coal mines or coal burning facilities, water can be polluted through the use of particulartechnologies (such as coal washing) or when pollutants are carried in runoff or as leachates33 from tailingsand storage piles. Mine tailings34 often release contaminants that were previously bound in impermeablerock formations. The quantity and type of contaminants released depends on a number of factors,including the local geology, hydrology and coal type. Emissions from coal-mine tailings commonlyinclude beryllium, cadmium, copper and zinc. Metals released into ground and surface waters can bebioconcentrated in food chains or can be ingested directly by humans and other organisms. The depositionof air-borne SO2 and NOx leads to the acidification of lakes and streams, which can have significantnegative impacts on aquatic ecosystems (see discussion in section 2.2, above). If mine tailings containsulfur compounds, acid drainage from tailing piles that are exposed to water can contribute to theacidification problem. Aluminum, cadmium, mercury and lead become more soluble as acidificationprogresses, resulting in higher levels of mobilized metals being released to ground and surface waters.

33 Substances from piles of coal or mine tailings that dissolve in water flowing on and through the piles are called leachates,having leached from the piles into the surface or groundwater.34 Typically piles of crushed rock that remain after the mineral being mined (e.g. coal, iron, or gold) has been extracted fromthe mined ore.


Ash piles at thermal power plants are another potential source for water pollutants. Leachate andrunoff from ash piles commonly contain heavy metals including arsenic, beryllium, cadmium, chromium,copper, iron, lead, mercury, nickel and vanadium. The type of contaminants present in each situationdepend upon the fuel type, combustion method, and pollution control methods used. Residues from powerplant boilers can contaminate water used in maintenance operations (such as the cleaning out or “blowdownof boilers) with the heavy metals listed above.

Leaking domestic, commercial, or industrial fuel storage tanks can contaminate surface or groundwater with gasoline, heating oil or other petroleum products. Drilling for oil can release brine deposits anddamage surrounding freshwater ecosystems. The negative environmental impacts of oil spills werediscussed above in the section on regional environmental issues. Water withdrawal for mine drainage cancause saltwater intrusion into freshwater aquifers. Uranium mines and mills, fuel fabrication plants,nuclear power plants, fuel reprocessing plants, and nuclear waste storage facilities all have the potential torelease radioactive materials to ground and surface waters.

Thermal power plants produce more heat than electric energy, and must dissipate this waste heat tothe environment. Large thermal and nuclear power plants generally withdraw surface water and evaporateit in cooling towers, which release heat (and water vapor) to the atmosphere. In sensitive aquaticecosystems, this withdrawal of water may be of concern. The adverse effects of aquatic thermal pollutioninclude lowered dissolved oxygen levels in the water, stress on aquatic organisms, and potential changes inspecies distribution, food chains and reproductive behaviors. Geothermal electricity generation plantsmust reject much more heat per unit of electrical output than other fossil or nuclear fired power plants35.The liquids produced from the exploitation of high-temperature geothermal reservoirs typically containlarge amounts of dissolved minerals that can pollute surface and ground waters if not properly treated.Thermal pollution of ocean waters is also an environmental concern associated with the development ofocean thermal energy conversion plants.

2.4.4 Solid and Hazardous Wastes

As urban areas throughout the world continue to grow rapidly, the disposal of solid wastesbecomes more and more problematic. Residents of industrial economies generate more refuse per capitathan do the residents of developing countries, but the waste management capabilities of many cities indeveloping countries are seriously over-burdened. The portion of total solid wastes produced by theenergy sector is generally small, but it can include hazardous and radioactive materials that demand specialhandling.

Energy-related solid wastes are primarily generated by mining and fuel combustion. The largesttwo sources of such wastes in the United States are coal mining and coal burning power plants,respectively. The mining of copper and other metals used in the transmission and distribution of electricityalso produces solid wastes. In the United States, about 100 million tons of coal refuse are producedannually by coal cleaning, an amount equal to approximately 30% of the mass of the raw coal processed(Murarka, 1987). Heavy metals tend to be associated with the heavy fraction of coal removed duringcleaning, and these metals therefore become concentrated in refuse piles. By 1978 approximately 3.5billion tons of coal refuse had accumulated in the United States (ibid.). Refuse piles can contaminate

35 This is because geothermal plants start with a heat source (geothermal energy) that has a low temperature relative to the hotgases from fuel combustion, and this low temperature limits the efficiency with which heat can be converted into electricity.Lower efficiency translates into increased heat production per unit of electricity generated.


ground or surface water via leaching or runoff (as noted above). They are also prone to spontaneouscombustion and therefore are possible sources of airborne emissions.

In the United States, over 90% of the electric utility industry's solid waste is produced from coal-fired power plants, which produced approximately 75 million tons of solid wastes in 1983. This quantityis slightly more than one percent of the total annual solid waste production in the United States (Murarka,1987). Wastes produced in large volumes by coal-fired power plants are fly ash, bottom ash, boiler slag,and wastes from flue (exhaust) gas emissions control systems. Fly ash leaves the combustion chamberwith the flue gases, while bottom ash is deposited at the bottom of the boiler. These types of ash areprimarily composed of the non-combustible materials (inorganic minerals) in the coal along with someunburned organic matter. Ash from emissions control processes is typically a mixture of fly ash, thepollutant controlled (often sulfur) and the substance used in the emission control system, such as calciumfrom limestone. The concentration of trace constituents in ash depends upon the coal type. Historically,15 to 25 percent of the solid waste tonnage generated by coal burning plants have been reused in variousapplications. Examples of such applications for coal ash include its use as a constituent of cement usedfor road and airport runway construction, as fill material, and as a constituent of other constructionmaterials (ibid.). Flue gas desulfurization wastes, one of a class of wastes resulting from emission controltechnologies, have potential for reuse in the production of gypsum for wall boards. The amount ofmaterial re-used depends upon a combination of technical and economic factors. The most commondisposal method for high volume ash is to transport it in a slurried or wet form to surface ponds. Drydisposal in landfills is also used. The environmental hazards associated with the wet disposal -- "ponding"-- of ash are primarily the leaching into water supplies of soluble metals such as lead, vanadium, cadmiumand cobalt. Fugitive dust can escape into the air from dry ash being transported to landfills. Whilelandfill sites generally require less land area and are easier to reclaim and restore than are ponding sites,leaching and runoff can still be a problem at dry disposal sites.

Other sources of energy-related solid wastes are oil and natural gas drilling, oil fired power plants,and the nuclear fuel cycle, although these are relatively minor (by weight) sources of solid wastes incomparison to coal technologies (DOE, 1983). The disposal of radioactive wastes was discussedseparately earlier in this Chapter.

Solid wastes can also be used as an energy source. In more than fifteen countries energy isrecovered from the incineration of municipal solid wastes (WRI 1992; Table 21.4). The type and quantityof pollutants emitted by waste incineration plants (with or without energy recovery) depends on factorssuch as the composition of the waste materials, and the combustion and emission control technologiesemployed. In many cases the benefits of waste reduction (the reduction of the volume of wastes viacombustion) are equal to, or more important than, the recovery of energy from the incineration process.


2.4.5 Electromagnetic Fields

Electric and magnetic fields (EMFs) result when electric currents pass through transmission linesor other electrical conductors. Over the past few decades there has been increasing concern over the healthhazards of exposure to EMFs. For the siting of new power transmission lines in particular, these concernshas become a topic of debate. The impacts of power frequency fields, those fields generated by electricityin the 50 to 60 Hz36 range, should be distinguished from fields associated with higher frequency sourcessuch as radio, x-rays, or microwaves. Power frequency fields are generally confined to an area relativelyclose to their source, while fields from higher frequency sources can be more broadly distributed.

While electric fields arise from a charge flowing in a conductor, magnetic fields are associated withthe motion of the charge. Electric field intensities are measured in units of volts per meter (V/m) orkilovolts per meter (kV/m). Electric fields can be blocked by trees or building walls, and thereforeexposure to electric fields from high voltage transmission lines is primarily limited to power line right-of-ways. Unlike electric fields, however, magnetic fields are not blocked by barriers such as trees or buildingwalls. Magnetic field strength is often presented in terms of magnetic flux density. The unit formeasurement of magnetic flux densities is the gauss (G). Flux densities from sixty-hertz power fields arecommonly reported in milligauss (mG). Both electric and magnetic fields are present in close vicinity toelectric appliances37.

The transfer of energy to cells resulting from exposure to electric and magnetic fields is relativelyminute, and therefore until the mid-1970's there was little concern over the possible negative effects ofexposure. Since then, however, epidemiological studies have suggested possible relationships betweenEMF exposure and cancer risk. Increased risk associated with EMFs has been found in studies ofleukemia, male breast cancer, and central nervous system cancers for both residential and occupationalexposures (Savitz, 1993). The research suggests a roughly two-fold increase in childhood leukemia riskwith exposure to high-level residential magnetic fields.

Experimental research has not yet been able to conclusively identify a mechanism for the biologicaleffects of EMF exposure. EMFs do not damage DNA and therefore are unlikely to act as cancer initiators,but EMFs may act as cancer promoters, or co-promoters. EMF exposure has been linked to changes inmelatonin hormones, calcium ions, cell division intervals, and cell growth. Further research is needed tomore carefully examine the relationships between EMF exposure and negative health impacts, especiallyconsidering the wide-spread presence of EMF's in electrified societies. Reflecting the uncertainty overthe definition of correct dose parameters and health effects, the Environmental Data Base does not currentlycontain a category for EMF exposure.

2.4.6 Occupational Health and Safety

Exposure to many environmental hazards are more intense in the work place than in the generalenvironment. In the United States, a review of occupational health and safety standards indicate thatsociety is willing to tolerate conditions and exposures in the workplace that are 10 to 100 times worse thanin the general environment (Ehrlich, Ehrlich, and Holdren, 1977). To some degree insurance and wages

36 The Hertz, abbreviated Hz, is a unit that measures the frequency with which a field (or other physical phenomenon) vibrates.One Hz is equal to one vibration per second.37 Much of the information on EMFs given here is drawn from OTA, 1989. This document provides a thorough backgroundon EMFs and their potential biological effects.


are assumed to compensate workers for accepting the risks associated with their workplace. Nevertheless,recognizing that market forces alone are unable to establish an "optimal level" of workplace hazardexposure, occupational health and safety standards are set in many countries.

Occupational health and safety risks are of acute and chronic types. Underground coal miningexposes workers to acute hazards such as explosions, entrapment, equipment accidents, or tunnel collapse,and chronic exposure to conditions that can lead to health problems such as black lung disease. Data isgenerally more available, and less controversial, for acute occupational hazards, such as the numberaccidents that lead to death, disability or illness. In the United States accidental deaths and injuries aremuch more common off-the-job than they are on-the-job, with motor vehicle accidents outweighing on-the-job accidents by a factor of more than two (U.S. Department of Commerce, Statistical Abstract of theUnited States 1992, Table 666, p. 419). The industry group of mining and quarrying, which includes oiland gas extraction, had the highest on-the-job death rate -- 43 per 100,000 workers -- of any industry groupin the United States in 1990, although the mining and quarrying rate was only slightly higher than that foragriculture -- including forestry and fishing -- and the construction industry (ibid.: Table 665, p. 419).When accident-related injuries and illnesses are considered in addition to deaths, mining and utilities are notnear the top of the list, ranking well below a number of manufacturing and agricultural industries (ibid.:Table 668, p. 420).

Although quantification is a more challenging task, chronic exposure hazards are also certain toexist. Studies of occupational exposure to energy related hazards such as radiation, toxic chemicals, andelectromagnetic fields have shown increased cancer risks38. With cancer and other diseases that may beassociated with chronic exposures, long latency periods39 and the presence of contributing or mitigatingfactors complicate the search for a clear understanding of certain occupational hazards.

2.4.7 Large-Scale Accidents

A number of energy technologies are associated with the remote possibility of accidents that havecatastrophic environmental consequences. It is often difficult for the public, or energy planners, to assessthis type of hazard, even if -- although this is rarely the case -- adequate technical information is available.One approach, probabilistic risk assessment, estimates overall risk according to both the severity and theprobability of an event. Such analysis provides an indication of comparative risk, but the public anddecision makers are likely to perceive and react to different types of risk in complex, and sometimes eveninconsistent fashions. In general individuals are willing to accept much higher levels of voluntary risk thaninvoluntary risk, and energy facilities primarily expose the public to the latter (Starr, Rudman, Whipple,1976).

In the realm of low probability/high consequence accidents nuclear energy tends to receive the mostattention, but other energy technologies are also potential sources for rare catastrophic events. Theimpoundment of water for hydroelectric projects can cause earthquakes (see Box 2.4). Dam failures canresult in catastrophic flooding. Liquefied natural gas (LNG) and liquefied petroleum gas (LPG) facilitiesare another source of potentially catastrophic accidents, as a spill of these materials could lead to massiveexplosions. Large oil spills, or the burning of oil wells (as during the Persian Gulf war) are examples ofthe catastrophic environmental possibilities of accidents at oil facilities.

38 For example see Savitz (1993) referring to electromagnetic fields and electric workers. It is beyond the scope of thisdocument to more fully discuss findings from occupational epidemiology, but for further information the reader is urged toconsult the several references provided elsewhere in this section under individual hazard headings.39 The periods between exposure of a person to cancer causing substances and the onset of cancer itself.


In the end, making decisions based upon risk assessments is more than a strictly analytical task,there are a large number of moral and political components involved in the comparison of different types ofrisk and the willingness to accept risks. Energy planners face a challenging task when incorporating theseissues in their decision-making framework.

2.4.8 Aesthetic, Visual, and Other Concerns

In many cases energy planning decisions will be influenced not only by the environmental impactsdescribed above, but by a less tractable set of considerations relating to how, for example, an energyfacility might “fit in” to its proposed neighborhood. Aesthetic and visual considerations, for example, cancause a power plant to be rejected for a site that is otherwise “ideal”. Perhaps the exhaust stack from theplant would spoil a beautiful vista, or would discourage tourists from visiting the area (thus harming thelocal economy) simply by its presence. Facilities such as power lines in remote areas can detract fromwilderness recreation experiences. Even the presence of wind turbines in an area might make residentsnervous about equipment failure, even if such fears are unjustified. Wind power, in fact, while having fewof the environmental impacts of, for example, fossil-fueled power plants, does raise a host of additionalenvironmental considerations, as described in Box 2.5.

Other concerns that fall under this general category include cultural and anthropological impacts.In Hawaii, for example, some groups oppose the use of geothermal power as being a desecration of thevolcano goddess, Pele. Their opposition on cultural grounds is thus in addition to concerns over the directenvironmental emissions of the proposed geothermal plants. Construction and operation of energyfacilities may also intrude on or (in extreme cases) destroy ceremonial native hunting, meeting, or burialgrounds, and in some cases could even render inaccessible important archaeological sites.

Noise generated by operating energy facilities can also be considered an environmental emission,and plays a role in the siting of certain types of plants. The addition of an energy facility to aneighborhood can also increase vehicle traffic; increased traffic has its own environmental consequences.

Aesthetic, visual, and other concerns are rarely directly amenable to quantitative analysis, but canoften play a key role in determining whether or not an energy project can be and ultimately is implementedin a given area.


BOX 2.5:POTENTIAL ENVIRONMENTAL AND SOCIAL IMPACTS OF

WIND POWER DEVELOPMENT AND OPERATION

SOURCE OF IMPACT DESCRIPTION

Land Requirements Wind farms require a large land area, due to the requirement that theindividual turbines in a wind farm must be spaced well apart to avoidinterference. In most instances, however, activities such as farming andranching can go on relatively unimpeded within the wind farm site.

Noise Noise from wind turbines comes primarily from the rotor blades as they slicethrough the air. Although wind machines built recently make substantiallyless noise than earlier models, noise from wind machines is potentially aproblem if wind farms are sited too close to residences.

Bird Strikes Birds can fly into fast-moving rotor blades of wind machines and be killed.While evidence to date indicates that birds generally learn to avoid thespinning rotors, some problems with bird strikes have been noted.

Interference withTelecommunications

Wind turbines interfere with television (mostly) and othertelecommunications signals, but these impacts seem to typically be localizedto the vicinity of the windfarm.

Safety Like any industry that includes moving machinery, safety is an issue withwind farm. Particular hazards from equipment failure include injury fromequipment failures such as blades breaking off. Safety issues have beentaken into account in wind turbine design, however, and there have been noreported public injuries from wind energy.

Visual Impacts The presence of wind turbines produces changes in views and skylines, andthus have a visual impact on their the area in which they are cited. Visualimpacts may be an especially important consideration if the turbines are tobe located in pristine or wilderness areas. The access roads and powerlines needed for grid-connected turbines can cause additional aestheticimpacts.

Source: M.J. Grubb and N.I. Meyer, Chapter 4, “Wind Energy: Resources, Systems, and RegionalStrategies” in Johansson et al, 1993.

Description of Major Environmental Effects Categories 43

3. Description of Major Environmental Effects Categories

3.1 Introduction

The long and diverse list of the potential environmental impacts of energy systems presented inChapter 2 demonstrates the need to consider a wide range of impacts when performing energy andenvironmental analysis. Although the consideration of many different impacts is admittedly more difficult,there is a very real danger, if one considers only a narrow range of impacts, of missing importantconsiderations. As a simplistic example, let’s say you wish to examine two different scenarios of electricitygeneration. In the first, only coal- and oil-fired power plants are to be used. In the second, most of the newpower will be supplied by hydroelectric plants. If you restrict your analysis to, for example, air pollutantor greenhouse gas emissions, the first scenario will appear much worse from an environmental perspective.This approach, however, misses the sometimes substantial environmental impacts of building and operatinga hydroelectric facility, including displacement of populations and changes in river flow; inclusion of theseimpacts in weighing the alternatives might lead you to make a different choice between the two scenarios.While it is rarely possible to cover all of the impacts of an energy system in a quantitative manner, it isimportant to design your analysis, and the analysis tools that you use, to enable you to take the full range ofimportant impacts into account.

Although the Environmental Database (EDB) provides information on a wide range ofenvironmental concerns, there are a number of types of environmental impacts, especially those that aretypically described in qualitative terms, that it does not yet cover. EDB lacks information, for example, onthe land requirements of energy facilities. Similarly, there are no data on the noise or aesthetic impacts ofenergy systems, which are often very site-specific. In many cases it is difficult to specify a direct causalrelationship between energy activities and their associated environmental impacts; EDB focuses on impactswhere causal relationships tend to be direct. In addition, there are many instances in EDB where impactcategories exist for a particular energy-using device or facility, but no data are yet available. Even in suchinstances when quantitative data on an impact are not readily available, it is important for the analyst tokeep them in mind for at least qualitative consideration, as these “non-countable” impacts may be as ormore important than the impacts that can be enumerated.

EDB includes coefficients describing the emissions and other direct impacts of the production anduse of energy. EDB is organized as a matrix, with its rows being sources of emissions and impacts, andits columns being the different types of emissions and impacts. The matrix entries are referred to in EDB aseffects or environmental loadings. Figure 3.1 shows how information is organized in EDB.


The remaining text in this Chapterpresents the loadings categories currently usedin the Core database of EDB, providing, foreach of the over 40 Effects, a brief descriptionof the category and the unit of measure of theloading, and a quick review of the majorsources and environmental impacts of eachtype of emission or impact.

In EDB, Effects categories aredescribed with a three-tiered labeling system.The first Effect label describes the media of theemission or impact (for example, "AirEmissions"). The second label describes thegeneral type of emission or impact (such as"Hydrocarbons"), and the third-level labeldescribes the specific species or type of emission or impact (like "Aldehydes"). Table 3.1, below, lists theeffects categories that currently appear in EDB, and the following matrix in Table 3.2 provides a quickoverview of the correlation between the effect categories and their environmental impacts. The text thatfollows these summaries is organized to correspond to the order of the EDB Effects list, and discusses eachthird-level effect category within the context of the broader second-level emission types, as appropriate.

Figure 3.1:EDB Program Structure

Coefficients Database

Effect categories

SOx NOx CO CO2 . . .

Demanddevices

Transformationprocesses

Sourcecategories

Environmental coefficients,documentation and references

Author Title Publisher Date

Bibliographic Reference Database


Table 3.1:EFFECT CATEGORIES IN THE ENVIRONMENTAL DATA BASE

AS OF EARLY 1995

AIR EMISSIONS (Level 1)

Level 2 Description Level 3 Description Unit TypeCARBON DIOXIDE NON-BIOGENIC MASS

BIOGENIC MASSCARBON MONOXIDE TOTAL MASSHYDROCARBONS TOTAL MASS

ALDEHYDES MASSFORMALDEHYDE MASSBENZENE MASSTAR MASSORGANIC ACIDS MASSMETHANE MASSVOLATILE HYDROCARBONS MASS

TOXIC HYDROCARBONS POLYCYCLIC ORGANIC MOLECULES MASSHYDROGEN SULFIDE TOTAL MASSMETALS LEAD MASS

ARSENIC MASSBORON MASSCADMIUM MASSCHROMIUM MASSMERCURY MASSNICKEL MASSZINC MASS

NITROGEN OXIDES TOTAL MASSNITROUS OXIDE MASS

SULFUR OXIDES TOTAL MASSSULFUR DIOXIDE MASS

PARTICULATES TOTAL MASSSIZE LESS THAN 10 MICRONS MASSFUGITIVE COAL DUST MASS

RADIOACTIVE CARBON-14 RADIATION LOADINGSIODINE-131 (ELEMENTAL) RADIATION LOADINGSIODINE-131 (NONELEMENTAL) RADIATION LOADINGSNOBLE GASES RADIATION LOADINGSRADON RADIATION LOADINGSTRITIUM RADIATION LOADINGS

AMMONIA TOTAL MASSTHERMAL EMISSIONS TOTAL ENERGY


Table 3.1 (Continued):EFFECT CATEGORIES IN THE ENVIRONMENTAL DATA BASE

AS OF JUNE 1993

WATER EFFLUENTS (Level 1)

Level 2 Description Level 3 Description Unit Type

SOLIDS TOTAL MASSSUSPENDED MASSDISSOLVED MASS

OXYGEN DEMAND BIOCHEMICAL MASSCHEMICAL MASS

SULFATES TOTAL MASSMETALS TOTAL MASS

CADMIUM MASSCHROMIUM MASSCOPPER MASSIRON MASSMERCURY MASSZINC MASS

SALTS TOTAL MASSNITRATES TOTAL MASSPHOSPHATES TOTAL MASSORGANIC CARBON TOTAL MASS

OIL AND GREASE MASSCHLORIDES TOTAL MASSAMMONIA TOTAL MASSCYANIDE TOTAL MASSRADIOACTIVE TRITIUM RADIATIONLOADINGS

ACTIVATION & FISSION PRODUCTS RADIATION LOADINGSTHERMAL EMISSIONS TOTAL ENERGY

SOLID WASTES (Level 1)

Level 2 Description Level 3 Description Unit TypeMINING WASTE INERT MASSTOTAL TOTAL MASSASH TOTAL MASSSCRUBBER SLUDGE TOTAL MASSRADIOACTIVE LOW-LEVEL (CURIES) RADIATION LOADINGS

LOW-LEVEL (VOLUME) VOLUME

OCCUPATIONAL HEALTH AND SAFETY (Level 1)

Level 2 Description Level 3 Description Unit TypeDEATHS TOTAL DEATHINJURIES TOTAL INJURYWORK DAYS LOST TOTAL WORK DAY LOST


Table 3.2:POTENTIAL ENVIRONMENTAL IMPACTS BY EDB EFFECTS CATEGORY

EDB "Effects" CategoryClimateChange

AcidPrecip.

LocalAir Polln

HumanHealthEffects

MaterialsEconomicImpacts

Impactson

TerrestrialEcosyste

ms

Impactson

AquaticEco-

systems

Concen.in FoodChains

LandUse

Impacts

Aestheticand OtherImpacts

AIR EMISSIONSCarbon Dioxide/Non-Biogenic XCarbon Dioxide/Biogenic N1Carbon Monoxide/Total m X X XHydrocarbons/Total, Volatile m X X X X XHydrocarbons/Aldehydes, Formaldehyde m X X X X XHydrocarbons/Benzene m X X m X X X XHydrocarbons/Tar m X X X X X XHydrocarbons/Organic Acids X m X X X X X XHydrocarbons/Methane X mHydrogen Sulfide/Total m X X X X X XMetals/Lead X X X X XMetals/Arsenic, Cadmium, Chromium, Mercury m X X X X XMetals/Boron, Nickel, Zinc m m m m XNitrogen Oxides/Total m X X X X X X X XNitrogen Oxides/Nitrous Oxide X m mSulfur Oxides/Total, Sulfur Dioxide m X X X X X X XToxic Hydrocarbons/Polycyclic OrganicMolecules

m m X X X X

Particulates/Total, <10 Microns, Fugitive CoalDust

m X X X X X X X

Radioactive/(All Types) X X X X X X XAmmonia/Total m m m m m mThermal Emissions/Total m m m m X

Notes:X = Effects have possible impacts in indicated group.m = Effects have possible impacts in indicated group, but any impacts are indirect or are likely to be minor.N1 Carbon dioxide emitted during combustion of biomass fuels will have an effect on global warming only if the fuels are produced

in a non-sustainable manner."Materials and Economic Impacts" include degradation of man-made materials by emissions, and the economic costs of repairing

pollution damage, and lost economic opportunities."Impacts on Terrestrial Ecosystems" include impacts on both managed (e.g. agricultural) and natural ecosystems; "Impacts on Terrestrial

Ecosystems" include effects on fisheries, wetlands, and groundwater."Aesthetic and Other Impacts" include impacts on air and water clarity, recreational opportunities, and social and cultural impacts.


Table 3.2 (Continued):POTENTIAL ENVIRONMENTAL IMPACTS BY EDB EFFECTS CATEGORY

EDB "Effects" Category

HumanHealthEffects

Materials/EconomicImpacts

Impacts onTerrestrial

Ecosystems

Impacts onAquatic

Ecosystems

Concent. inFood Chains

Land UseImpacts

Aestheticand OtherImpacts

WATER EFFLUENTSSolids/Total, Suspended, Dissolved m X XOxygen Demand/Biochemical, Chemical m X X XOrganic Carbon/Total X m m X X m XOrganic Carbon/Oil and Grease X X X X X X XSulfates/Total m X X XMetals/Total, Cadmium, Chromium, Mercury X m X X XMetals/Copper, Iron, Zinc m m X XSalts/Total m m m X m XNitrates/Total m m m X m XPhosphates/Total m m m X m XChlorides/Total m m m X m XAmmonia/Total m m m mCyanide/Total X m XRadioactive/(All Types) X X m X X XThermal/Total (If new EDB cat. is added) X XSOLID WASTESMining Waste/Inert X X X X XTotal X X X X m X XScrubber Sludge/Total m m m X XRadioactive/Low Level (All Types) X X X X X X X

OCCUPATIONAL HEALTH AND SAFETYDeaths/Total X X XInjuries/Total X X XWork Days Lost/Total X X XNotes:X = Effects have possible impacts in indicated group.m = Effects have possible impacts in indicated group, but any impacts are indirect or are likely to be minor."Materials and Economic Impacts" include degradation of man-made materials by emissions, and the economic costs of repairing

pollution damage, and lost economic opportunities."Impacts on Terrestrial Ecosystems" include impacts on both managed (e.g. agricultural) and natural ecosystems; "Impacts on Terrestrial

Ecosystems" include effects on fisheries, wetlands, and ground water."Aesthetic and Other Impacts" include impacts on air and water clarity, recreational opportunities, and social and cultural impacts.

3.2 Air Emissions

EDB covers several classes of air emissions, including the so called "criteria" pollutants, toxic airpollutants, greenhouse gasses, particulate matter, and others. All coefficients for emissions to the air, withthe exception of radioactive and thermal emissions, are presented on a mass basis, for example, kg ofcarbon dioxide per unit fuel consumed.

Carbon dioxide (CO2), the major greenhouse gas both in terms of quantity emitted and in itsoverall effect on global warming, is released whenever a fuel that contains carbon is combusted, oroxidized. It is released in quantities generally proportional to the carbon content of the fuel. CO2 emissionfactors in EDB were principally estimated based on fuel carbon content, as described in Section 4.3 of thismanual. Carbon dioxide is not directly toxic to most plants and animals40, thus its principal environmental

40 Though humans, animals and other aerobic organisms cannot live in an atmosphere of pure carbon dioxide because theycannot live without oxygen.


impact is on climate, as has been discussed in Section 2.1, in the previous chapter. CO2 emissions fromfossil and biomass fuels are treated separately in EDB as "Non-Biogenic" and "Biogenic" carbon dioxide,respectively. As carbon dioxide is taken up and emitted by many terrestrial and oceanic sources and sinks,its lifetime in the atmosphere is difficult to specify, but may be on the order of 100 years41. CO2 emissionfactors are provided in EDB for most for most source activities involving fuel combustion, and most of theCO2 factors in EDB are derived based on fuel carbon content.

Non-biogenic ("fossil fuel") CO2 : Non-biogenic emissions are those derived from combustionof fossil fuels and other sources of carbon dioxide (such as geothermal wells) for which the carbonemitted is either of geological origin or, as is the case with coal, oil, gas, and peat, was formedfrom biological material but on geological time scales, that is, so long ago that the fuels areessentially non-renewable. Non-biogenic emissions constitute a net addition of CO2 to theatmospheric pool of the gas, at least on a human time scale.

Net Biogenic CO2.. Biogenic emissions of carbon dioxide, in contrast, result from biomasscombustion, and do not constitute net additions of CO2 to the atmosphere, under conditions ofsustainable biomass harvesting. Under these conditions, the CO2 released upon combustion ofbiomass-derived fuels can be recaptured during photosynthesis in the next biomass growth cycle42.Non-sustainable harvesting of biomass, leading to soil and land degradation and, in extreme cases,to deforestation and desertification, will cause net additions of CO2.

Carbon monoxide (CO) is produced, in concentrations that vary widely across different types ofcombustion devices, when carbon-based fuels (both fossil and biomass fuels) are burned. CO results whencombustion of these fuels is incomplete, that is, when the carbon in a fuel is not completely oxidized tocarbon dioxide. As a consequence, emissions of carbon monoxide are primarily a function of combustionconditions; inefficient combustion generally increases CO emissions. Motor vehicles tend to be the majorsource of CO emissions in most areas, with older vehicles being the primary culprits. Carbon monoxide iscreated in oxygen-starved, fuel-rich combustion conditions, such as by low speed and idling vehicles incongested urban areas. Household biomass- and coal-burning stoves are also significant sources of CO,while industrial boilers and utility power plants, for example, will produce relatively little CO whenoperated properly. Carbon monoxide is converted (oxidized) in the atmosphere to CO2, and typicallyremains in the atmosphere for a few months at most43. Emission factors for carbon monoxide are providedfor many emissions sources in EDB, and are derived from many sources, especially USEPA documents44.

Carbon monoxide is a local air pollutant, with respiratory impacts, and contributes both directly(as it oxidizes to CO2) and indirectly to the increase in greenhouse gas concentrations in the atmosphere.CO's respiratory impacts on human and animal health stem primarily from the ability of the CO moleculeto bind to hemoglobin, the oxygen-carrying molecule in blood, and thereby reduce the supply of oxygen tothe brain in human and other tissues. Since carbon monoxide binds more readily to hemoglobin thanoxygen, even relatively low concentrations of CO in the air can lead to carbon monoxide poisoning, which

41U.S. Environmental Protection Agency, Policy Options for Stabilizing Global Climate, Report to Congress, Main Report,December 1990. USEPA Division of Policy, Planning, and Evaluation, Washington, D.C., USA. Report No. 21P-2003.1, pageII-38.42 For example, if a hectare of corn were grown to produce 3,000 liters of ethanol, and the ethanol was then used as fuel, therewould be a temporary addition of CO2 to the atmosphere, but the next year, planting the same hectare of corn would reclaim asimilar quantity of carbon dioxide from the atmospheric pool. The key here is that biogenic emissions of CO2 can result in nonet addition of CO2 to the atmosphere, and no net loss of carbon from the terrestrial biomass.43USEPA 1990c, ibid.44Please see the attached Annotated Bibliography of EDB References for further information about EDB data sources.


is characterized by headaches, dizziness, and nausea in mild cases, and loss of consciousness and death inacute cases45.

Hydrocarbons (sometimes abbreviated as HC, or VOC--for volatile organic carbon), are emittedfrom energy-sector activities as either 1) products of incomplete combustion of carbon-based fuels, or 2) byevaporation or leakage of fuels and lubricants from fuel production, transport, and storage facilities (forexample, oil wells, tanker ships and trucks, and petroleum refineries) or from fuel-using devices (such asautomobile gas tanks and engine crankcases). Individual hydrocarbon species exhibit various degrees oftoxicity in different animal species. Many hydrocarbons are also carcinogenic (promote the growth ofcancers) and/or promote genetic mutations that can lead to birth defects. Hydrocarbons can also bebioconcentrated as discussed in Section 2.2, leading to amplified toxic effects in animals at the top of thefood chain. As a class, hydrocarbons contribute to the production of photochemical smog and of groundlevel ozone, which are dangerous to human health due to effects on the respiratory system . High ozonelevels also damage crops, forests, and wildlife, as described in Box 3.1, below.

With the exception of methane, hydrocarbons as a class are likely to contribute indirectly to globalwarming through their effect on tropospheric ozone concentrations (methane contributes directly).Different hydrocarbon species have different lifetimes in the atmosphere, with some chemicals havinglifetimes of hours or days, while other, less reactive molecules remain in the atmosphere longer. As ofApril 1995, total hydrocarbon emission factors are reported for many EDB Source categories, as aremethane emissions, but there are relatively few emission factors for the other hydrocarbon species andclasses. Most of the hydrocarbon and methane emission factors in EDB are derived from USEPAliterature, while emission factors for other types of hydrocarbons are often from U.S. Department ofEnergy documents.

45See, for example, Doull et al, 1980, pages 317 - 319. This reference notes that if CO has an ambient concentration of 0.1percent by volume in air, hemoglobin in human blood will, at equilibrium, be approximately half saturated with CO and halfwith oxygen. This level of CO saturation is often associated with acute carbon monoxide poisoning.

BOX 3.1:SOURCES AND IMPACTS OF TROPOSPHERIC (GROUND-LEVEL) OZONE (O3)

Tropospheric ozone can present a significant health risk in or downwind from many urban areas. Ozoneis a secondary pollutant, produced in the presence of sunlight, nitrogen oxides (NOx), and volatilehydrocarbons. In the U.S., national ambient air quality standards are frequently exceeded in manyareas, particularly during the summer months. Elevated ozone concentrations can lead to acuterespiratory symptoms and aggravation of previous illnesses, and are suspected of increasingvulnerability to chronic respiratory illness. Ozone can also cause cracking and oxidation of rubber andother elastomers, fiber damage, and may result in damage to paint, plastics, asphalt, and othermaterials.

Long-range transport of ozone and ozone precursors can lead to elevated ozone concentrations in ruralareas, where exposed crops and forests can suffer damage. Ozone damage to crops has been heavilystudied, and dose-response curves have been developed for major crops of economic value. Cropyields can drop 15% or more under ozone stress (RCG/Hagler, Bailly, 1993).

While estimating the emissions of ozone precursors, including volatile hydrocarbons and nitrogen oxides,can be relatively straightforward, the processes of ozone formation and destruction is very complicated;sophisticated computer programs must be used to model atmospheric ozone chemistry.


In addition to a category of "Total" hydrocarbons, EDB includes separate Effects categories for anumber of different hydrocarbon species, as well as for the general class of VOCs. These species, andtheir general environmental characteristics, are discussed below. In addition to VOCs, subclasses ofhydrocarbon emissions often found in the literature include:

• Non-Methane Hydrocarbons (NMHCs), a grouping often used in the greenhouse-gas field,• Total Organic Gases (TOG), and• Reactive Organic Gases (ROG)46.

These different divisions of hydrocarbon emissions can create some confusion, as they overlapsubstantially, but not necessarily in a well-defined way. As a consequence it is advisable, when usingEDB, to review the coefficient entries for the total hydrocarbons "effects" category for those sources thatare of interest for information on what hydrocarbon species are included in the value given. The specifichydrocarbon species for which effects categories are currently provided in EDB, and some of the specificenvironmental hazards of those species, are described below.

Methane (CH4) is emitted as a by-product of fuel combustion, through leakage from natural gas,oil and coal extraction, transmission, and distribution facilities, and from other agricultural andnatural (non-man-made) sources. In general, fuel combustion is a relatively minor contributor tooverall CH4 emissions relative to the other sources of the gas. Methane is relatively non-toxic tohumans and animals, but in high enough concentrations it can cause suffocation (for example,through major methane leaks in a closed building, or methane seepage into a coal mine). Methaneis, however (as was noted in Section 2.1) a powerful greenhouse gas, contributing to globalwarming both directly and (to a lesser and still uncertain extent) through its interactions with bothtropospheric ozone and stratospheric water vapor.

Aldehydes, chemically speaking, are hydrocarbons that contain an oxygen molecule attached by adouble bond to a carbon atom, which is also attached to a hydrogen atom. They have the generalchemical formula RCHO47, where R is a hydrocarbon group (such as the methyl group, -CH3).Aldehydes are products of incomplete combustion, with motor vehicles being a major source ofemissions, and also form in the atmosphere in reactions between hydrocarbons and nitrogencompounds, and other pollutants. Aldehydes are extremely reactive molecules, and are majorcontributors to the odor and irritation of the eyes, nasal passages, and respiratory tract caused byexposure of humans and animals photochemical smog. As reactive molecules, aldehydes may alsodamage the surfaces of plants. The two main aldehyde species of concern are formaldehyde(discussed below) and acrolein. Both are detectable by odor in the at a concentration of about 1part-per-million, and both cause irritation of mucus membranes and other effects at concentrationsof a few ppm or less (Doull et al, 1980)48.

Formaldehyde has the chemical formula H2C=O, where "=" represents a double bond. It isproduced by incomplete combustion of hydrocarbon fuels, especially by motor vehicles. Inparticular, it is one of the major hydrocarbon pollutants produced by motor vehicles operating onnatural gas, methanol, and ethanol fuels. Formaldehyde is also used as a preserving medium forhuman and animal tissue samples (including as an embalming fluid), and thus has a familiar and

46The designations TOG and ROG are often used by the California Air Resources Board (CARB) in their documents, includingMethods for Assessing Area Source Emissions in California, September, 1991, CARB, Sacramento, CA, USA (CARB 1991a).47Morrison and Boyd (1973), page 617.48 Pages 625 - 626.


readily detectable odor. Formaldehyde makes up an estimated 50 percent of the total aldehydes inpolluted air. Its effects on human and animal health are as noted under "Aldehydes", above.

Benzene is a hydrocarbon species containing six carbon atoms arranged in a hexagonal ringstructure, with a hydrogen atom attached to each carbon (C6H6). Its ring structure and thearrangement and nature of the bonds between its carbon atoms make benzene an aromaticcompound in chemical terminology, and confer on it special reactive and toxicological properties.Benzene is a constituent of crude oil and of refined fuels, particularly motor fuels, and is also usedas a solvent and a chemical feedstock. It is emitted, typically in concentrations ranging from afraction of a percent to a few percent of total hydrocarbons, by fuel combustion activities, fromrefinery processes, and from oil and gas extraction, transport and storage operations (CARB1991b). Emissions from motor vehicles are a major source of benzene.

Benzene has a number of different impacts on human health. Human exposure to benzenein high concentrations (greater than 20,000 ppm) leads to death within minutes due to respiratoryfailure and collapse of the circulatory system, but the primary cause of these responses to acutebenzene poisoning seems to be its effect on the central nervous system. In lower concentrations,benzene affects a variety of different tissues and organs in a variety of different ways, earning the ita description by Doull, et al (1980)49, as "an insidious and unpredictable toxicant". The effects ofbenzene on health include possible effects on the central nervous system, injury to the blood-forming tissues (such as the liver) and other blood abnormalities (including anemia). Becausebenzene is readily soluble in blood and in fatty tissues, it may persist in the body for several daysafter exposure. One of the major concerns about chronic exposure to benzene vapor is its possiblerole in promoting cancers, including leukemia. This role has been suggested by various studies.Benzene has also been shown in animal studies to cause birth defects. Dissolved in fresh or saltwater, benzene, like other hydrocarbons, may be toxic to aquatic and marine life.

Tar is a complex and varying mixture of different hydrocarbon species, principally composed ofheavier hydrocarbon species (that is, hydrocarbon molecules with higher molecular weights).Emissions of tar typically come from combustion of coal and of heavier petroleum fuels, such asbunker or residual oil, and production of coke and other non-energy products. Poor combustionconditions may increase releases of tar. The heavy hydrocarbon species in tar tend to condenseout of the air onto surfaces, including forming aggregates with particulate matter in the air.

Chronic exposure of humans and other animals to tar in the air can cause or exacerbaterespiratory problems, as tar can build up in the lungs. Tar condensing from the air can build upon plant surfaces and interfere with plant growth. Some of the individual substances in tar maythemselves be toxic and or carcinogenic (cancer-promoting).

Organic Acids, as the name implies, are organic molecules that include acidic, or carboxyl groupsof the form -COOH. They are also referred to as carboxylic acids. These hydrocarbon speciesare very reactive, and thus may not appear very often in emissions estimates because they reactwith other chemical species in exhaust gasses to form new molecules before they can be measured.Like the mineral acids (including the nitric and sulfuric acids that are produced by reaction withsulfur and nitrogen oxides with water, as described below), organic acids have a destructive effecton human and animal tissues, particularly as eye and respiratory system irritants. They also, due

49 Pages 485 - 488.


to their acidic nature, can degrade plant surfaces, thus affecting plant health, and can eat away atnatural and man-made materials and structures causing economic and ecological damage.

Volatile Hydrocarbons are a sub-class of total hydrocarbons loosely defined as those species thatdo not readily condense out of the air. These species include many of the other types ofhydrocarbons listed here, and constitute the bulk of hydrocarbon emissions. The sources andeffects of this class of emissions are substantially the same as those listed above for hydrocarbonsin general. A separate category for these is emissions is provided in EDB because volatilehydrocarbons are sometimes reported separately from (or instead of) total hydrocarbon emissions.

A separate classification for atmospheric emissions of Toxic Hydrocarbons is provided in EDBbecause some key sources of emission coefficients track these species separately from generalhydrocarbon emissions. At present EDB has very few emission factors for these substances, butestimates for emission factors exist and are being developed by a number of sources, including theU.S. EPA and the State of California Air Resources Board. As the name implies, toxichydrocarbons are notable for their poisonous effect in low doses on plants and animals. Onesource category for toxic hydrocarbons is provided in EDB, namely Polycyclic Organic Moleculesor POM. POM are a class of molecules containing two or more hydrocarbon "rings". In somecases, these ring structures mimic or interact with molecules in living cells, contributing to theirtoxicity. Energy sector activities that release POM and other toxic hydrocarbons includecombustion of coal and oil products, wood and wood-product wastes, municipal solid waste, andsimilar fuels. Other sources of air emissions of molecules in this class include the chemicalindustry, food preparation (including the frying of meats), and disposal of wastes--particularlyplastics and chemical wastes--via incineration. The major health concern for toxic hydrocarbonsare their possible or probable (depending on the species considered) effects as carcinogens orteratogens (substances capable of causing genetic or reproductive abnormalities) in humans.These compounds can also be bioconcentrated, and thus their emissions may have adisproportionate effect on animals at the top of the food chain (including humans).

Emissions of Metals to the atmosphere are principally the result of combustion of fuels thatcontain various metal species as trace constituents, contaminants, or additives. More rarely, atmosphericemissions of metals may come from metal atoms that have "worn" off of combustion equipment such asengine parts, turbine blades, or boiler grates. Many different species of metals are emitted from energy-sector activities, as well as from non-energy industrial activities, and their environmental effects vary withthe species and with their concentration in the air. Some metals are necessary nutrients for plants andanimals at low concentrations, but are toxic at higher levels. EDB provides a number of different sourcecategories for atmospheric metals emissions, but at present (1995) emission factors have been entered for asignificant number of sources only for lead emissions (based primarily on USEPA data). As most metalsare emitted as part of particulate matter, the lifetime of metals in the atmosphere is equal to that of theparticles to which they are attached, which depends on the particle size (smaller particles remain in theatmosphere longer) and prevailing meteorological conditions.

Lead (which has the chemical abbreviation Pb) is a soft gray metal used in many applications. Itis a pollutant of major concern, due both to the amount of lead emitted and to its effects on humanhealth. Lead is found in widely varying concentrations in solid and unrefined liquid fuels such ascoal and crude oil--as well as in the heavier refined oil products such as residual oil--and is emitted,often associated with particulate matter, when theses fuels are burned. By far the most importantsource of lead emissions from the energy sector, however, is the lead that is used as an "anti-


knock" additive in gasoline. Lead is added to gasoline as tetraethyl lead (Pb(CH2CH3)4)--a formof lead in which short hydrocarbon chains (ethyl groups) are bonded to a lead atom--in manycountries, though its use as a fuel additive is being phased out in the United States and othernations. In the early 1970's, the average gallon of "regular" gasoline in the United Statescontained 2.6 grams of lead (0.68 g/liter; Ehrlich et al, 1977)50. This has been reducedsubstantially since. More recent figures on the lead content of gasoline (grams per liter) in majorcities around the world range from 0 in Moscow to 0.026 in New York and Los Angeles, 0.15 inTokyo, 0.6 in Beijing, 1.16 in Manila, and 1.5 in Karachi (WHO/UNEP, 1994)51. Tetraethyl leademissions are cause of special concern because this form of lead is more mobile in the environmentthan elemental lead (Pb metal).

Once emitted, lead may remain and be transported in the atmosphere in association withfine particulate matter, or may settle fairly near where it was emitted (such as a roadway).Virtually all of it eventually either settles to the ground or mixes with water in the atmosphere andis incorporated into rain or snow. Lead can thus reach humans and other animals by beingabsorbed through the skin, by being absorbed through the lungs during breathing, or by beingingested with food or drink. Since lead can be concentrated in the food chain, its environmentalconcentration may be amplified before it reaches humans and other carnivores. The symptoms oflead poisoning on humans are well known, and include "loss of appetite, weakness, awkwardness,apathy, and miscarriage" (Ehrlich et al, 1977)52. Lead affects many organs and systems withinthe body, including the central and peripheral nervous systems, the kidneys, and the blood synthesisand circulation systems (Doull et al, 1980)53. Domesticated and wild animals living in areaswhere lead emissions are substantial are subject to lead poisoning. It has been shown that leadlevels in relatively remote areas, such as high forests in the northeast United States, have beenincreasing substantially, but it is not yet known what direct effects this contamination may have onplant growth (Freedman, 1989)54.

Arsenic metal (As) is a poison of some renown, and as a consequence finds use in insecticides andherbicides, anti-fouling paints, and wood preservatives, as well as in forming alloys with othermetals (including lead). It is emitted to the atmosphere in relatively low concentrations fromfacilities that burn coals that contain the metal as a trace contaminant. Metal smelters are anothermajor source of atmospheric arsenic emissions.

Arsenic compounds are more prevalent in nature than the metal itself. The symptoms ofacute arsenic poisoning (exposure to high doses of the metal over a short period--minutes orhours) in man and animals include gastric tract disturbances, dryness of the mouth and nose,muscle spasms, delirium, and loss of consciousness. Symptoms of chronic (exposure to lowerconcentrations over a longer term) arsenic poisoning include fatigue, peripheral nervous systemproblems; and blood problems. Arsenic has also been implicated as a carcinogen (that is, inpromoting the growth of cancers) and in causing birth defects. The environmental effects ofarsenic are enhanced by its tendency to accumulate in plant and animal tissues.

50 Pages 568 - 571.51 WHO and UNEP note that these values may be average lead content figures or upper limit values.52 Page 568.53 Pages 415 - 421.54 Pages 76 - 80.


Boron (B) is a light element that is grouped with the metals. It is a plant nutrient, and is found inmany different forms and compounds, including the detergent additive borax (Na2B4O7) and boricacid, which is used in foods and disinfectants. Boron compounds are emitted in very smallquantities when fuels -- mostly coals -- that contain the element are burned. The acute effects ofboron compounds on the health of humans and other animals include damage to the central nervousand respiratory systems, as well as to the kidneys, though most incidents of health problems relatedto boron compounds are associated with industrial exposure, rather than to emissions from theenergy sector.

Cadmium (Cd) often occurs in nature in association with zinc and lead, and is widely used inelectroplating, in manufacturing of batteries, and in many other applications. As with arsenic andboron, some cadmium is emitted to the air during the combustion of fuels containing the metal55,but most of the health risks of cadmium poisoning are due to industrial emissions (for example,emissions from metal smelters). Cadmium is toxic at very low concentrations--less than 1 ppm.The primary health impacts of both acute and chronic cadmium poisoning are on the kidneys, therespiratory system, and on bone formation. It has been suggested that chronic cadmium exposureis implicated in increasing levels of hypertension (high blood pressure) in the general population,but the link is by no means certain (Doull et al, 1980)56. Cadmium is a pollutant of some concernfor both animals and humans because it is retained in the kidneys, and, as it is not readily excreted,tends to build up in the body and in ecosystems. Atmospheric cadmium associated withparticulate matter can be find its way into the food chain when it is deposited on plants, which arethen eaten by animals.

Chromium (Cr) is widely used for chrome plating of other metals (such as automobile steel) aswell as in paint and pigment manufacturing, in metal alloys, and in the tanning of animal skins.Atmospheric emissions of chromium from the energy sector are from combustion of fuelscontaining the element and from the wear of metal parts in combustion equipment. Chromium,and compounds of chromium including chromate and chromic acid, can cause medical problems ofthe skin, nose and throat, and liver, and may also be carcinogenic, though chromium is an essentialnutrient at low concentrations (Doull et al, 1980)57.

Apart from lead, Mercury (Hg) is perhaps the best-studied metallic pollutant. Mercury is used inthe production of chlorine (which is used in plastics manufacture) and of caustic soda, and is alsoused in paints, pesticides and herbicides, medicines, wood-pulp making, metals refining, and otherapplications. Like lead, mercury is a trace contaminant of oil and especially coal, though itsconcentrations in these fuels vary widely (Ehrlich et al, 1977)58. It is emitted to the atmospherefrom power plants and other combustion facilities in combination with particulate matter.Mercury occurs in the environment primarily as metallic mercury, as sulfides, sulfates, orchlorides, or in complex with several types of organic molecules (known collectively as "organicmercury").

55P.R. Ehrlich et al, (1977, p. 575) suggest that cadmium is present in crude oil and coal at roughly 0.5 and 1 part per million,respectively. These authors also note that cigarette smoking is a substantial source of cadmium exposure.56 Pages 428 - 435.57 Pages 441 - 442.58 Page 571 of this reference gives a range of 0.01 to 33 ppm by weight for the mercury content of different coal species.


The symptoms of mercury poisoning in humans include “headache, fatigue, irritability,tremors, and other nervous disorders"59. These neurological symptoms are the origin of the phrase"mad as a hatter", as hat makers routinely used mercury in their trade. Mercury is retained in thebodies of animals, and is concentrated by the food chain. The most well-publicized type of thisbioconcentration leads to high concentrations of mercury and mercury compounds in large foodand sports fish such as tuna and swordfish60. Large predatory birds have also been adverselyaffected by the mercury in their food.

Nickel (Ni) is used extensively in electronics, metallurgy, batteries, and other applications, as wellas its familiar usage in coins. Nickel occurs in nature in combination with iron and copper, and ispresent as a trace element in some coals and in crude and residual oils. Nickel has also been usedas a gasoline additive. Metal smelters are a significant source of atmospheric nickel. With theexception of the compound nickel carbonyl (Ni[CO]4), nickel is not as highly toxic as mercury andsome other metals, but can, in high enough concentrations, cause nasal and lung cancers, and otherrespiratory problems61. Nickel can be concentrated by certain types of plants, and nickel in thesoil (naturally-occurring or present as a pollutant) can be rendered more mobile by the action ofacidifying substances such as nitrates and sulfates (see discussion of nitrogen and sulfur oxides,below).

Zinc (Zn) is used in large quantities for making galvanized iron and steel, in paint, and in rubber-(vulcanized tires), glass-, and paper-making. Major emissions of zinc to the atmosphere are frommetal smelting activities, with coal and oil combustion making a smaller contribution. Particlescontaining zinc are also released near roadways through wear of automobile parts and tires. Zincis an essential trace nutrient, but can be toxic in high doses, causing gastric (digestive system)difficulties if taken in with food or drink, and "metal fume fever" when zinc oxide fumes areinhaled, as sometimes occurs in industrial settings (Doull et al, 1980)62. Like other metals, zinc isconcentrated by aquatic and terrestrial plants, and is rendered more mobile in the environment byacidification of soils or waters (for example, due to acid deposition; Freedman, 1989)63.

Nitrogen Oxides (NOx), comprise a group of molecules that can contribute to local air pollution,acid deposition, and global climate change. They are among the most frequently reported atmosphericemissions, and the most commonly regulated. Nitric oxide (NO) is generally produced during high-temperature combustion. It is photochemically oxidized to nitrogen dioxide (NO2) in the atmosphere.Nitrous oxide (N2O), a potent greenhouse gas, is produced at much lower levels, and is discussed below.

The nitrogen in nitrogen oxide combustion products is derived from nitrogen present in variouscompounds in the fuel and from molecular nitrogen (N2) that makes up nearly four-fifths of molecules inthe air. Higher combustion temperatures (which generally promote more complete combustion) tend toincrease NOx formation, as more N2 from the air is oxidized. It is important to stress that the role ofatmospheric nitrogen in NOx formation means that combustion of even "clean" fuels such as natural gas,methanol, or hydrogen, which contain at most trace amounts of nitrogen, can produce substantial amountsof nitrogen oxides. The presence or absence of metals and other surfaces that can catalyze (increase the

59P.R. Ehrlich et al, (ibid, p. 572), Doull et al (eds), 1980, ibid. Pages 421 - 428.60Mercury concentrations five to ten thousand times higher than the average concentration in seawater have been found in largefish. .61Doull et al, 1980, pages 265, 452; Freedman, 1989.62 Pages 461-462.63 Pages 78, 105.


rate of) formation or destruction of NOx also plays a role in determining the overall level of nitrogen oxideemissions.

As shown in Table 2.4 above, natural and anthropogenic sources account for approximately equalshares of global emissions. However, since about three-quarters of human NOx emissions result from fossilfuel combustion, much of this from vehicles, urban areas can experience elevated NOx concentrations.Once emitted, NO and NO2 have atmospheric lifetimes on the order of months64.

Nitrogen oxides can contribute to environmental problem in several ways. Short-term exposure toelevated NO2 concentrations (0.2 to 0.5 ppm) can cause respiratory symptoms among asthmatics. Indoorfuel combustion, particularly from gas stoves or traditional fuel use, can lead to elevated indoor levelswhich have been associated with increased respiratory illness and reduced disease resistance amongchildren. (RCG/Hagler, Bailly, Inc., 1993). Nitrogen oxides contribute to the formation of troposphericozone and nitrate aerosols (fine particulates), major air pollutants that are discussed in Box 3.1. NOx

species also may have a role in global warming (see Section 2.1), but the extent of this role is still a subjectof debate.

Atmospheric emissions of NOx contribute to the formation of the photochemical smog prevalent inmany urban areas, and thus have a general detrimental effect on the respiratory health of humans and otheranimals, as well as on visibility. In high concentrations, NOx can injure plants, though the requiredconcentrations usually only exist near a large point source of the pollutant. The major hazard to plantsfrom nitrogen oxide emissions may be through the effect of NOx on ozone formation (Freedman, 1989)65.Atmospheric nitrogen oxides in high concentrations cause respiratory system damage in animals andhumans, and even in relatively low concentrations they can cause breathing difficulties and increase thelikelihood of respiratory infections, especially in asthmatics and other individuals with pre-existingrespiratory problems (Doull et al, 1980)66.

EDB provides two categories for nitrogen oxides: a Total effect category, and a separate categoryfor nitrous oxide, which as a greenhouse gas has properties distinct from the rest of the group.Emission factors for total nitrogen oxides are provided for many of the fuel-combustion sourcecategories in EDB, and most have been taken or derived from U.S. EPA documents. Emissionfactors for nitrous oxide are available for a smaller subset of EDB sources, and are at this timequite uncertain. Most of the N2O factors in EDB are also derived from U.S. EPA documents.

Nitrous oxide (N2O) is a very powerful greenhouse gas (on a weight basis) but, as indicatedabove, although the quantities emitted are subject to large uncertainty, they appear to be a small(but highly variable) fraction of total nitrogen oxide emissions. The process of N2O formationduring and after combustion is still poorly understood. Unlike the other nitrogen oxides, nitrousoxide has a lifetime in the atmosphere of approximately 150 years (USEPA, 1990c). A recentsystematic error in the measurement of nitrous oxide emissions has left the actual magnitude ofN2O emission factors in some doubt, as is discussed in section 4.4.

Hydrogen Sulfide (H2S) has a distinctive odor most often associated with rotten eggs, and thehuman nose can detect it in very low concentrations (about one part per billion in air). It is emitted during

64Note that once emitted, NO is often oxidized to nitrogen dioxide by combination with oxygen in the air.65 Pages 16-17.66 Pages 622-625.


extraction of oil, natural gas, and geothermal energy, from some industrial processes, from municipalsewage and waste disposal, and from a number of natural sources, including volcanic areas and wetlands.It is thus a pollutant of major importance mostly in the locales of major energy and industrial facilities.Hydrogen sulfide in relatively high concentrations is toxic to humans and animals. In non-lethalconcentrations it is an irritant of the eye and of the respiratory system (Doull et al, 1980)67. In theatmosphere, hydrogen sulfide is oxidized to sulfur oxides (SO2 , SO3, and sulfates, which haveenvironmental effects of their own, as noted below) with an average lifetime (as H2S) of less than a day(Freedman, 1989). Hydrogen sulfide emission factors are provided in EDB primarily for geothermalelectricity generation facilities, and were derived from U.S. Department of Energy documents.

As with nitrogen oxides, two source categories are provided for Sulfur Oxides (SOx) in EDB.The first, Total sulfur oxide emissions (including sulfur dioxide SO2, sulfur trioxide SO3, and sulfate SO4

2-)covers all of the different species of sulfur oxide emissions, while the second, Sulfur Dioxide, covers onlySO2, the major SOx species released to the air by human activities. Quite often, in the emission factorliterature, total SOx emissions will be expressed as SO2 equivalents. Total SOx emission factors areprovided for many EDB source categories, and most of these emission factors are drawn from U.S. EPAdocuments. EDB reports SO2 emissions separately from SOx emissions more rarely, typically when thedocument from which an emission factor is drawn specifies that the emissions reported are of sulfurdioxide.

Energy related sulfur oxide emissions are generally proportional to the fraction of sulfur in fuelssuch as coal and crude oil. For some fuels, the fraction of sulfur can exceed 10 percent. The fuels withthe most sulfur are the coals and heavy oils used in electric-utility and heavy industrial boilers. When thesefuels burn, sulfur combines with oxygen in the combustion air to yield SOx. Metal smelters and otherindustrial processes are also key sources of SOx emissions.

Sulfur oxides can react with water and oxygen in the atmosphere to yield sulfuric acid, one of themajor components of acid rain. (The impacts of acid deposition were discussed in Section 2.2). SO2 itselfcan damage plants, with acute exposure to the gas causing death of part or all of a plant, and chronicexposure, though the threshold at which plants are affected varies widely among different plant species(Freedman, 1989)68. In humans, exposure to SO2 at high levels (above about 5 ppm; the averageconcentration in urban air in the U.S. is about 0.2 ppm) causes respiratory problems (Doull et al, 1980)69,though exposure of to significantly lower doses can sometimes exacerbate existing respiratory problems insensitive individuals. In developing countries and other areas where coal is used as a home heating and/orcooking fuel, SOx can be an important health hazard as an indoor air pollutant.

Particulate emissions, sometimes abbreviated TSP for Total Suspended Particulates, are, as onewould guess from the name, microscopic particles of soot and ash -- which often include other substancessuch as metals, hydrocarbons, and sulfur compounds-- that are emitted from combustion processes or arecarried into the air from roads, agricultural activities, or during transport or storage of finely divided solidmaterials such as crushed coal.

Anyone who has traveled down a dusty road can appreciate the effect of particulate emissions onthe human upper respiratory system (nose, throat), but smaller particles can also penetrate deep into thelungs, where they can aggravate existing respiratory problems and increase the susceptibility to colds and

67 Pages 328 - 330.68 Pages 10-16.69 Pages 611-619.


other diseases. Particulates can also serve as carriers for other substances, including carcinogens andtoxic metals, and in so doing can increase the length of time these substances remain in the body.Particulate matter in the air impairs visibility and views, and particulate matter settling on buildings,clothes, and other humans may increase cleaning costs or damage materials. Particulate matter is animportant indoor air pollutant in areas where open or poorly-vented household cooking and heatingequipment is used, particularly with "smoky" fuels such as wet biomass, crop and animal residues, andlow-grade coals. Particulate matter can settle on plants, reducing plant growth by reducing plants' uptakeof light and carbon dioxide.

The amount of particulate matter emitted during combustion is a function of the fuel type, theamount of non-combustible fuel contaminants such as ash present in the fuel, the firing conditions, and thelevel of pollution control equipment used. TSP emissions cover a wide range of particle sizes, from thosethat are nearly visible to the naked eye to particles less that a micron (one millionth of a meter) in diameter.The size classifications of particulate matter are important, as A) the smaller the particle, in general, thelonger it will remain in the atmosphere, and the farther it can be dispersed from its source, and B) particlesin smaller size ranges are a more serious concern to human health, as, unlike larger particles, they are notfiltered out by the upper respiratory system.

EDB provides three source categories for particulate emissions. Entries in the Total particulatecategory give the mass of all particles emitted per unit fuel consumed or produced. These entriesare provided for many source categories in EDB, and, as with most of the criteria pollutants, arederived primarily from U.S. EPA documents and databases, with data on biomass fuel combustioncoming from a variety of international sources.

The second category of particulate emissions counts those particles of Size Less Than 10 Micronsin diameter, often abbreviated "PM10" in the literature. This is the most commonly cited sizeclass, and includes those emissions of most concern to human health. PM10 emissions are givenfor a large number of EDB categories, though many categories only have data for total emissions.The U.S. EPA, the California Air Resource Board, and others maintain "speciation" manuals anddatabases of the size classes of particulate emissions by emission source. These can be used, ifappropriate, to expand the data in EDB to additional size categories.

A separate source category under particulates is provided for Fugitive Coal Dust, that is, coaldust that escapes from coal trains and other transport system, or is emitted during the production,processing and storage of coal. EDB contains relatively few entries for this specific particulatepollutant; most derived from U.S. Department of Energy documents. Coal dust is of specialconcern as a particulate pollutant due to the presence in the coal particles of heavy metals andother trace coal constituents. It is inhalation of coal dust that causes the "black lung" diseasefrequently seen among coal miners, particularly in mining operations where mine ventilation anddust masks are inadequate.

Radioactive emissions to the atmosphere stem primarily from the operation, maintenance, anddecommissioning70 of nuclear power plants and the production, refining, storage, and disposal of thematerials that fuel them, but can also be released in very small quantities during activities such as coalmining and combustion. Non-energy sector activities that emit radioactivity include medical X-rays and

70Decommissioning refers to the process of dismantling a nuclear power plant when its lifetime is complete, and rendering itand the nuclear materials it used and generated stable and "safe" for long-term storage.


other health science applications of radiation. Emissions during operation of nuclear power plants can bedirect emissions (either routine or accidental) from the reactor itself, emissions of "activation products"(such as metals that are part of the reactor that have been irradiated by operation of the reactor and havebecome radioactive themselves), and emissions from low-level and high-level wastes in storage. Emissionsof radioactive materials are typically measured in Curies, abbreviated Ci, which specifies the number ofparticles emitted per second from a radioactive material.

The effects of radioactive emissions on human health have been documented by the populationexposed following the explosion of the nuclear bombs over Hiroshima and Nagasaki in Japan, and by theChernobyl reactor accident in the Ukraine. These health effects include acute effects such as radiationsickness (characterized by nausea, damage to bone marrow, and other symptoms), and chronic effects suchas increases in cancer rates, genetic effects, prenatal problems, effects on fertility, shortening of life, andcataracts of the eye (Doull et al, 1980)71. It should be noted that the amount of radioactivity to which thepublic is exposed during routine operation of nuclear plants is generally not thought sufficient to contributeto these problems. Radioactive emissions settling on agricultural areas can be carried to a widerpopulation through farm products such as milk. Animals and plants exposed to radiation can also suffershort and long-term damage.

EDB includes several source categories for radioactive emissions: Carbon-14, Iodine-131(Elemental), Iodine-131 (Nonelemental)72, Noble Gases (including Krypton and Xenon), Radon,and Tritium (H-3). At present, EDB contains emission coefficients for radioactive substances foronly a few nuclear technologies, and most have been derived from U.S. Department of Energydocuments.

Ammonia is a reduced73 form of nitrogen (NH3) widely used as an industrial feedstock,agricultural fertilizer, and household cleaning agent. Ammonia is emitted in low concentrations by someenergy sector activities, including coal and oil combustion, oil refining, gasification of coal and biomass,and geothermal energy conversion. EDB contains a limited number of ammonia emission coefficients forsome of these technologies. Man-made emissions of ammonia are much smaller, overall, than naturalemissions, which stem from anaerobic microbial activity in areas such as wetlands. Ammonia does nottypically remain in the atmosphere long, as it can react with oxygen in the atmosphere to form nitrogenoxides, can be absorbed by water in the atmosphere, or can, in its electrically charged form (ammoniumion, NH4

+), combine with sulfates and other ions to form or add to particles in the atmosphere. Wheninhaled, ammonia is an irritant to the respiratory system, but these effects are typically limited toindividuals working directly with the compound in poorly ventilated areas. Ammonia gas can injureplants, but is rarely present, except in heavily polluted areas, in high enough concentrations to causedamage (Freedman, 1989)74.

Thermal Emissions to the atmosphere include the radiation of heat and the release of steam (forinstance, from cooling towers) from energy sector activities. Thermal power plants, including both fossil-fueled and nuclear facilities, produce approximately twice as much energy in the form of heat as they do inthe form of electricity. When cooling towers are used to dissipate heat from power plants, steam is

71 Pages 497-530.72That is, iodine emitted as a compound with other elements.73 “Reduced” and “Oxidized” are characteristics of molecules. Generally, more reduced species tend to be richer in hydrogenatoms and have fewer oxygen atoms than oxidized species. For example, Methane, CH4, is the most reduced form of carbon,while CO2 is one of the most oxidized forms.74 Page 17.


typically released. These plumes of water vapor can change the local climate by increasing the localhumidity and producing shadowing (from the vapor plume), fogging, and icing under some conditions.Excess water vapor can also accelerated the degradation of materials such as wood and metals, and canincrease mildew problems. When several very large power plants are located close to one another, a "heatisland" may be created that has the potential to disrupt circulation patterns in the local atmosphere.Thermal emissions can be estimated fairly easily for most types of power plants, but at present there are noemission factors in this category in EDB.

3.3 Water Effluents

Emissions of pollutants to bodies of water -- from ponds and streams to lakes, rivers, and oceans --are covered by a number of emission categories in EDB, though at present there are relatively few emissionfactors for these “effects”. Those factors that are presently available are principally derived from U.S.Department of Energy and World Health Organization documents. In general, emissions to water are mostlikely to originate in energy transforming installations such as oil refineries, petroleum wells, coal mines, orethanol production facilities. Water effluents can also be created by aqueous emissions from the cleaning oflarge fuel combustion facilities such as boilers75. Water effluents are typically measured in mass units,with the exception of radioactive emissions, which are measured in units of radiation loadings. Briefdescriptions of the categories of water emissions covered in EDB, and their environmental impacts, areprovided below.

The emissions of Solids to bodies of water are described in two EDB categories. Suspendedsolids are materials that mixed into water but not dissolved, such as slurries of mud, sand, ash, or otherparticles, while Dissolved solids include salts and other materials in solution in effluents and in bodies ofwater receiving the pollutants. Suspended solids reduce the visibility and the penetration of sunlight intowater, potentially affecting the behavior of fish and other species, and reducing the productivity of marineand aquatic plants. Depending on the nature of the suspended material, suspended solids can also affectwater chemistry, as can dissolved solids. Both types of water emissions can affect humans through theirimpact on drinking water quality, and on the quality of water used for recreation and industrial purposes.

Oxygen Demand is a measure of the amount of oxygen would be required by aquatic microbes todegrade the organic material present in a water sample. Two measures of oxygen demand are Biochemicaloxygen demand (BOD) and Chemical oxygen demand (COD), which vary primarily by the laboratorymethods used to measure them76. Energy-sector sources of oxygen-demanding effluents includepetroleum refineries and fuel-alcohol production facilities. The effect of effluents which raise BOD andCOD is (depending on the types of organic matter present) to decrease the amount of oxygen available foraquatic animals by increasing the demand for oxygen by microorganisms in the water that degrade theorganic matter. In extreme circumstances, as in rivers and lakes heavily polluted with sewage and/orindustrial effluents, the amount of oxygen in the water can fall to zero (anoxic conditions) resulting in the

75"Boiler blowdown" solutions, which contain minerals cleaned from boiler tubes, are an example here.76Biochemical oxygen demand is measured by placing a sample in an incubation bottle with a "seed" culture of bacteria, andmeasuring the dissolved oxygen content of the water before and after an incubation period, often five days (BOD5). Chemicaloxygen demand is measured by subjecting a water sample to strong chemical oxidants (potassium dichromate and sulfuricacid); the COD of the sample is proportional to the amount of potassium dichromate used to reach a point at which an indicatorreagent changes color. BOD and COD values of the same sample can differ depending on the constitution of the sample,including the types of organic and inorganic matter present. See Standard Methods for the Examination of Water andWastewater (American Public Health Association, Washington D.C., USA; reissued periodically) for a description of thesetests.


death of most larger aquatic flora and fauna. Oxygen demanding effluents can also adversely affect waterused for drinking, irrigation, industrial processes, fishing and recreation.

A category for Organic Carbon effluents to water is provided in EDB. This is another way(along with BOD and COD) of measuring the input of organic matter to aquatic ecosystems. With theexception of toxic hydrocarbon species that may be included in emissions in this class, the effects oforganic carbon emissions will be similar to those described for the oxygen demand categories, above.

Oil and Grease emissions to water can come from petroleum extraction and transport activities(such as oil tankers) or from the operation of energy-using devices such as automobiles. Oil and greasecan foul the surface of the water, injuring or killing aquatic and marine birds and mammals, as well as fishand other organisms. Heavier oils can sink to the bottom and pollute sediments, harming shellfish andother bottom-dwelling plants and animals. Some components of oil and grease emissions are toxichydrocarbons that become dissolved in the water and are taken up by aquatic and marine organisms,causing a variety of impacts. Oil and oil products can also contain heavy metals, which have their owntoxic effects (as noted above; Freedman, 1989)77.

Sulfates are produced by a number of processes, including the "wet" scrubbing of boiler stackgases to remove sulfur oxides, and the cleaning of boilers to remove sulfate-containing "scale". Additionof sulfates change water chemistry, sometimes resulting in changes in species compositions. Water high insulfates must often be treated before use as drinking water or in industrial processes.

EDB includes effects categories for several different types of emissions of Metals to water. Thespecies covered are Cadmium, Chromium, Copper, Iron, Mercury, and Zinc. Energy sector activitiesthat can produce these emissions include oil refining, oil and coal extraction, and coal processing, thoughother industrial activities (metals refining, tanning of animal skins) probably release larger quantities ofthese effluents to water bodies than the energy-related sources. The health and environmental effects ofmany of these metals were covered under Air Emissions, above, though water-borne metals pose slightlydifferent hazards, in some cases, than emissions to the air. The potential environmental impacts of themetals not covered earlier (copper and iron) are described below.

Copper (Cu) is familiar as the principal metal used in electrical conductors (wires), and in manyother uses. In high enough concentrations, copper in aqueous environments can kill algae (insome cases it is used for this purpose in water purification), thus affecting the basis of the aquaticfood chain. Though copper is an essential nutrient for some organisms, such as shellfish, fish aresensitive to copper, as are animals such as sheep and cattle, in which copper can cause blood andliver disorders. In humans high doses of copper can cause acute poisoning, the symptoms ofwhich include vomiting, jaundice, low blood pressure, and coma (Doull et al, 1980)78.

Iron (Fe) is an essential nutrient for humans and many other animals, being a key element in theblood-cell protein hemoglobin, among its other physiological functions. The symptoms of acuteiron poisoning in humans include digestive system abnormalities, neurological problems includingcoma, and possible jaundice. A few diseases are attributed to excess iron in the diet (chronic ironpoisoning), including "hemochromatosis" which results in abnormal skin pigmentation and liver,spleen, and bone marrow abnormalities (Doull et al, 1980)79.

77 Chapter 6.78 Pages 443-444.79 Pages 445-447.


Salts is a general EDB category that can encompass a number of chemicals, including sulfates,chlorides, nitrates, and others, that are soluble in water, that is, they dissolve to yield anions (negatively-charged ions) and cations (positively-charged ions) in solution. Sodium chloride (NaCl), commonly usedas table salt, is an example, being formed of a sodium ion Na+) and a chloride ion (Cl-). The amount ofsalt present in solution is a general indicator of water quality in fresh waters. Salts affect aquaticecosystems in different ways, depending on the species present and the concentrations. Some species haverather narrow ranges of salt tolerance, and are adversely affected when average concentrations rise above(or below) a certain level. As salt concentrations increase, water may have to be treated or may be unfitfor human uses such as irrigation or drinking water.

EDB provides separate categories for Nitrates and Phosphates, which are classes of salts thathave the nitrate (NO3

2-) and phosphate (PO43-) ions as their respective anions. As salts, excessive levels of

nitrates in aquatic environments can affect water chemistry and the ability of different organisms tosurvive, but it is nitrate’s activity as a fertilizer that is probably most of concern to the environment.Nitrates and phosphates are used widely as nutrient amendments for terrestrial agriculture, so it is notsurprising that they promote the growth of algae and other aquatic plants. This increased productivity inlakes and other bodies of water is called eutrophication. In the short run, increased algal growth helpsprovide more oxygen and food for other aquatic species, but can also change the structure of aquatichabitats, which can change species compositions. Potential adverse effects of eutrophication also includeunwanted "blooms" of algae that are unpalatable to fish and other herbivores, produce toxic substances, orimpart an unpleasant taste or odor to water. In extreme cases, massive blooms of algae can die off, andthe resulting oxygen demand (from the bacteria that degrade the dead algae) can result in periods of oxygendepletion, which can result in fish kills and/or the evolution of noxious gasses such as hydrogen sulfide(Freedman, 1989)80.

Chlorides are also a class of salts, and include sodium chloride, the most abundant salt inseawater. The general effects of chlorides on the environment are as described above for salts.

Ammonia is readily dissolved in water. In sufficient concentrations, it can change waterchemistry by modifying (increasing) the pH. In addition, ammonia, when converted to ammonium ion, canact as a nitrogen fertilizer to stimulate the growth of algae and aquatic plants, and can thus contribute toeutrophication. Process wastewaters from petroleum refineries contain ammonia.

Cyanide (CN-) is a notorious poison toxic to humans and other organisms. Cyanide interfereswith the body's ability to utilize oxygen resulting, in extreme cases, in respiratory and circulatory failure.

Radioactive emissions to water have the same types of effects on aquatic and marine ecosystemsas they have on terrestrial ecosystems (see text above on radioactive air emissions), though someradioactive particles will not travel as far in water as they do in air. EDB provides categories foremissions of Tritium and of Activation and Fission Products, which are released in small quantities byoperating nuclear reactors, and have been released in larger quantities during accidents.

Thermal (heat) emissions to water, expressed in terms of energy, are produced by power plantsthat discharge waste heat into rivers, lakes, or oceans. If the heat is released in such a way as tosignificantly raise the temperature of the receiving body of water (and a rise of only a degree or so can besignificant, it can alter the composition of aquatic and marine ecosystems in favor of those that thrive in 80 Chapter 7.


warmer waters. These warmer-water species are often less commercially desirable. In addition, thermalemissions to water can lower levels of dissolved oxygen81, which can have a negative impact on fish andother organisms (Ehrlich et al, 1977)82.

3.4 Solid Wastes

Several different categories for solid waste emissions are provided in EDB, but, as with wateremission, there are at present relatively few emission coefficients for these categories. Most of theexisting emission factors are derived from U.S. Department of Energy documents. EDB provides acategory for Total solid wastes of all types, plus several specific categories, as described below.

Mining Wastes, as the name implies, are solid wastes from mining operations, including suchenergy-sector activities as the mining and processing of coal and of oil shale. EDB contains an emissioncategory for Inert mining wastes, that is, those materials that are not likely to react with air or precipitationor to be mobile in the environment. Though their toxicity may be low, piles of inert mining wastes by theirphysical nature change landscapes and thus the environment, potentially resulting in the displacement ofanimal species, changes in vegetation (mining wastes are not usually particularly fertile substrates for plantgrowth) and/or aesthetic impacts.

An environmental effluent of considerable importance, particularly for large boilers and other typesof facilities fueled with solid fuels (especially coal) and heavy oils83, is Ash84. There are two importanttypes of ash emissions from fuel combustion. Bottom ash remains in the boiler, oven, furnace, or stoveafter fuel combustion is complete. Fly ash is particulate matter that is captured by pollution-controlequipment such as cyclone collectors and fabric filters (see footnote reference for sources describingpollution control options). These two effluent categories are combined, at present, in a single Total ashcategory. Beyond the physical effects of piles of ash on landscapes and on ecosystems, ash from coal andoil combustion contains heavy metals, toxic organic compounds, and other potentially damaging substancesthat can leach (that is, be dissolved in rainwater and flow out of the pile) out of ash disposal sites andpotentially affect ecosystems. If piles of ash are left uncovered, wind can blow smaller ash particles intothe air, where their potential effects are those noted for air emissions of particulates. Disposal of ash isalso an economic problem, particularly in countries where landfill space is scarce, where ash is defined as ahazardous waste, or where ash must be transported a long distance for disposal.

Scrubber Sludge is an effluent of some concern for coal-fired industrial and electricity-generationequipment. A scrubber is a device in which exhaust gasses pass through (typically) a solution of achemical such as calcium carbonate (limestone) in water. This process "scrubs" sulfur oxides and othercomponents from the exhaust gas stream, and produces a sludge containing calcium sulfate, ash particles,and other chemicals. Some of these compounds can leach from storage areas into the environment,potentially contaminating surface and ground waters.

81 This is both a physical phenomenon, as oxygen is less soluble in warmer waters, and a biological one, as higher temperaturepromotes the growth of microorganisms, which then take up oxygen faster.82 Page 670.83The combustion of wood and other biomass fuels also yield varying amounts of ash, but their volume per unit energy isgenerally lower than for coal combustion, and the concentration of potentially toxic substances in the ash is also lower.84Coal ash may also pose an environmental hazard in countries where coal is widely used as a domestic cooking and heatingfuel.


Radioactive solid wastes are of a number of types. Most radioactive wastes are created during theoperation or decommissioning of nuclear plants, or during the mining, refining, and fabrication of nuclearmaterials used for reactor fuels or weapons. A small amount of low-level waste is also generate by uses ofradioactive compounds for medical, industrial, and research purposes. EDB currently includes two effectscategories for low-level radioactive wastes, one expressed in terms of radiation loadings (Curies) and theother in terms of waste Volume. The former category provides a measure of the radiological hazard of thewaste, while the latter gives an idea of the storage/disposal volume that would be required per unit energyprovided. Low-level wastes contain relatively small amounts of radioactivity, and the risk of human healtheffects or environmental damage from these wastes are low if the wastes are properly disposed of. Low-level waste disposal facilities are, however, expensive to build and difficult to procure locations for, thusthey are of significant concern from a social and economic point of view. High-level radioactive wastes,with large amounts of radioactivity per unit volume, are even more difficult to dispose of in a safe manner.Storage facilities for these wastes must be designed to last up to tens of thousands of years, withstandseismic activity, and keep wastes completely contained far into an uncertain future. The siting of high-levelnuclear waste sites has proven extremely difficult in the United States due to concerns over groundwatercontamination and other environmental issues, as well as social concerns. The latter include concerns as tothe fairness of siting waste facilities in areas, generally with very low population densities, that have hadfew of the benefits of the electricity generated using the nuclear fuels, and issues of intergenerationalequity.

3.5 Occupational Health and Safety Effects

EDB includes several categories for direct occupational health and safety impacts. These areDeaths, Injuries, and Work Days Lost. In each case, the unit of measure for the impact coefficient inEDB is in numbers, so, for example, the deaths coefficient for coal mining would be expressed in numberof deaths per tonne coal mined, and so on for injuries and work-days lost. The energy-sector activities thatare of the most concern from an occupational health and safety standpoint are typically fossil-fuelextraction and processing technologies such as oil and gas production and refining, coal mining. Themining and processing of nuclear fuels, generation of nuclear power, and harvesting of biomass fuels canalso be of concern from an occupational health and safety standpoint. EDB includes a limited number ofcoefficients for these effects, taken from a combination of U.S. Department of Energy, World HealthOrganization, and other documents from the international literature. Occupational deaths, injuries and lostwork-days from energy sector activities can have social and economic impacts beyond those on theindividuals affected through their effect on families, on work force productivity, and on the perception ofthe social costs of certain energy resources.

3.6 Other Effects

As noted in the introduction to this chapter, there are a number of important emissions and impactsof energy use and energy conversion systems that have not yet been included in EDB. In some cases,generic factors (or ranges of factors) for these emissions and impacts are scheduled for inclusion in laterversions of EDB. In other cases, it will continue to be up to you, the planner, to include these impacts inyour analyses as appropriate. Some of the emissions and impacts not now covered in EDB include:

• The amount of land used by energy facilities. This would include the sites occupied by fossil-fueled power plants, the reservoir areas of hydroelectric facilities, the area occupied by solar


photovoltaic panels, and the area used for nuclear and other waste facilities. Note that there aresignificant differences between some of these types of land use: land used for photovoltaic panels,for example, can often be fairly easily reclaimed for other uses, while land used for nuclear wastefacilities may be restricted to that use indefinitely.

• The use of water in energy facilities. Water use includes water consumed, that is, rendered

unavailable for other uses, and water that is merely used temporarily, then returned to the watersupply in a form suitable for re-use.

• The use of materials, such as cement, steel and other metals, plastics, and wood, in the

construction of energy facilities and products. The use of these materials may have direct orindirect impacts of their own, and should be considered in a true full-fuel-cycle analysis.

• Noise emissions by fuel-producing and -using devices. Noise emissions must be defined at a

specified distance from the source. • The frequency and results (deaths, injuries, illnesses) of major catastrophic accidents, such as dam

failures or nuclear mishaps, as well as more minor (but possibly more frequent) incidents. • Aesthetic considerations. • Impacts on biodiversity.

This chapter has described the environmental loadings that are currently included in EDB, andbriefly discussed some of those that are not. In conjunction with the information provided in Chapter 2,which covered the general relationships between energy technologies and environmental impacts, thematerial presented here provides essential background for the task of estimating the potential range ofenvironmental impacts associated with alternative energy development options. In the next chapter wepresent an overview of how the loadings included in the EDB have been estimated. It is important foranalysts to clearly understand the genesis of these loading figures so that they may be used appropriately.

Environmental Loading Data: Sources, Estimation, and Uncertainty 67

4. Environmental Loading Data: Sources, Estimation, and Uncertainty

4.1 Introduction

The preceding sections of this manual introduced some of the broader issues in energy-environmentanalysis (Section 2), and provided a guide the environmental loading categories found in the EDB (Section3). In this section, we focus on the methods and data used to estimate loadings for various energyactivities. These data are the heart of EDB itself, namely the factors for air, water, and solid wasteemissions, for on-site health and safety impacts, and for resource use or degradation. The bulk of thissection will focus on the first of these three categories: the emission factors that constitute the majority of"generalizable" data and of EDB entries. Methods used to estimate on-site health and safety impacts arealso mentioned. We discuss how to determine the appropriate form of emission factors for a given type ofanalysis, how emission factors are measured, and what to do in instances where emission factors are notavailable (in EDB or elsewhere) for a particular technology. We also discuss the many uncertainties,errors, and limits to applicability of emission factors, some of the categories of emission factors that aremost sensitive to local conditions, and some of the major sources of emission factors used to create the coredatabase of EDB.85

4.2 Emission Factors: What they are and where they come from

Emission factors or coefficients (we use the terms interchangeably) describe the quantity of apollutant that is released per unit of fuel consumed, produced, or lost. In EDB terminology, emissionfactors describe the relationship between an energy activity or Source category (e.g a type of automobileor electricity generating plant) and an Effect category (a specific pollutant). A few sample emissionfactors, together with units and descriptions of what they mean, are given in table 4.1, below.

85 A full listing can be found in “Environmental Data Base (EDB): A Listing of Core Database Coefficients”, SEI-B, May1995.


Table 4.1: Sample Coefficients From EDB

Emission

Factor Units

Effect

Category

Source

Category Description

2550 kg/tonne Air/Carbon

Dioxide

Coal-fired

Stove

There are 2550 kg of carbon dioxide released to the

atmosphere per tonne of coal burned in a household stove.

1.24 gm/GJ Air/Hydrogen

Sulfide

Geothermal

Power Plant

There are 1.24 grams of hydrogen sulfide released to the air

per GJ of geothermal energy used by a power plant.

38.1 gm/liter Solid

Waste/Total

Ethanol

Production--

Corn Based

There are 38.1 grams of solid wastes produced for each liter of

ethanol produced using corn as the biomass feedstock.

On-Site Impact

Factor Units

Effect

Category

Source

Category Description

1.16E-8 deaths/bbl Occupational

H&S/Deaths

Oil Production-

-US Onshore

There are 1.16 x 10-8 accidental worker deaths per barrel of

crude oil output from an oil production facility, or 116 deaths

for every billion barrels of oil produced.

NOTE: In EDB and associated documents, the exponent or power of ten follows the letter "E". "E-9" isshorthand for "10-9". Thus, 1.16E-8 = 1.16 x 10-8 = 1.16 x .00000001 = .0000000116.


Box 4.1 Fuel Chain Analysis

Related to the determination of cause and effect in the relationship between energy activities and emissions factors isthe consideration of full fuel chain analysis. When people use energy--for example when we turn on a light bulb, drive to workin a car, or cook our dinner--we are finishing a chain of related activities that makes energy use possible. This chain ofactivities, sometimes called a fuel chain or cycle, may be short as burning fuelwood just collected nearby, or as long as:

Locating oil deposit ---> Drilling oil well ---> Extracting crude oil ---> Transporting crude to refinery ---> Refining oil intogasoline --->Transporting to filling station ---> Filling cars with fuel ---> Driving

At each point along these chains of activities, the various energy technologies used can have impacts on theenvironment. These impacts can be in the form of pollutant emissions to the air, water, or soil, can affect--either directly orindirectly--human or animal health and safety, can be physical or chemical changes that alter the way that the environmentfunctions, or can be a combination of many different individual effects.

When comparing energy options, it is important to consider environmental impacts beyond those of fuel productionand use, to the "upstream" and "downstream" effects. For instance, an analysis of the environmental costs and benefits ofsubstituting electricity for, say biomass use in household stoves would be incomplete if it did not consider, in addition to theimpacts of fuel consumption at the point of end use, the impacts of burning fuel (if applicable) to generate electricity, theimpacts of the electricity transmission and distribution system, and the host of resource production impacts: oil production, oilspills, coal/peat mining, etc. A different list of potential impacts will be applicable to the biomass alternative, in this example.The point here is that unless the environmental impacts of the full fuel chain are considered--qualitatively and/or quantitatively--there is a grave risk of overlooking a set of significant impacts by considering only a subset of the system that makes energyuse possible.

Leaving aside consideration of economic impacts, let us assume that we are comparing the use of electric householdstove with biomass-fired stoves, and, further, that the electricity will come from coal-burning power plants and the biomass islocally produced in a sustainable fashion. If the borders of our comparison between these alternatives are drawn tightly,encompassing only the fuel end use, then the electric stove looks like a good bet: it is efficient, requires no fuel harvesting ortransport on the part of the household, and produces no emissions. The biomass stove, in contrast, requires the household tofind, harvest, and carry the biomass back to the house, and as it burns producing, in varying amounts depending on the type offuel, stove and firing conditions used (see section 4.5), produces a host of potentially hazardous atmospheric emissions.When we expand our window of analysis to encompass more of the fuel cycle, the comparison doesn't look quite so one-sided.Building a coal-fired power plant requires land to be committed for use as the power plant site for the life of the installation andperhaps longer, while land used to grow biomass may be used for other purposes, such as farming and pasture. The powerplant itself is a source of atmospheric emissions, including direct and indirect greenhouse gasses, solid wastes, and sometimesliquid wastes as well, while sustainable production of biomass fuels will typically produce fewer emissions. Coal plants requirefuel, which must be mined. Both coal production and coal transport have attendant impacts on the environment and on humanhealth and safety. Electricity transmission and distribution lines are associated with yet another set of environmental concerns.Thus drawing the lines of analysis to encompass more of the fuel cycle yields a radically different picture than an initial look atjust the end-use impacts of fuel use.

LEAP and EDB are set up to allow the evaluation of fuel cycle impacts. Furthermore, as part of a recent UNEP/SEIcollaboration, a new LEAP Fuel Chain program was developed and is available as part of LEAP 95 and subsequent versions. Areport describing fuel chain analyses in two case study countries, Venezuela and Sri Lanka, is available from SEI-B.86

86 SEI/UNEP Fuel Chain Project: Final Report, SEI-B, May 1995.


Emission factors are measured and/or estimated numbers that relate effects to sources. Emissionfactors are thus numbers that allow the energy/environment planner to estimate quantities of emissions andother environmental effects or impacts associated with activities such as the tonnes of fuel burned usingcoal stoves, or the barrels of oil passing through a refinery.

4.2.1 Who Collects Emission Factors, and Why?Emission factors are determined by empirical measurement or by various estimation techniques.

Some of the methods used are discussed later in this section. Emission factors are typically measured orestimated by researchers working for governmental or international agencies, industrial firms, universities,or research institutes. The motivations for collecting emission factor data are as diverse as the people whocollect them.

1. Government agencies, such as the Environmental Protection Agency in the United States, collectemission factors (or contract with private firms or academic researchers to do the collection) for severalreasons. First, many governmental agencies wish to establish inventories of pollutant emissions orother environmental effects. These inventories are lists of the quantities of pollutants emitted,sometimes broken down by source location and/or by the economic sector and sub-sector. Theinventories are calculated by multiplying emission coefficients by the level of corresponding activity(coal combustion, for example) in the location or sector under study. This is essentially the sameapproach applied when LEAP and EDB are used together to estimate emissions. Emission factors,and the inventories produced using emission factors, are used to establish baselines for monitoring ofenvironmental conditions, for the design of pollution reduction programs, as tools to identify areas orsectors with specific environmental needs or opportunities, and as inputs to environmental impactmodels. Impact models use emission factors and emission inventories to estimate the impacts ofemissions on, for example, air or water quality. Periodic inventories show the trends of environmentalemissions over time, which is useful for the planning of future government regulations or investments.Emission factors are also used for standard setting and for checking compliance with performancestandards of energy technologies, such as power plants and automobiles. In many countries,automobiles must meet certain standards of emissions per mile traveled, and emission factors for thevarious types of automobiles are periodically measured and checked to assure that manufacturers arecomplying with regulations.

2. Some industrial firms also measure and estimate pollutant emissions to monitor their facilities’

compliance with governmental regulations. They may also collect such data in order to studyproduction process efficiencies and/or to investigate opportunities to make production processescleaner. Manufacturers of emission reduction equipment or low-emission technologies seeking topromote their wares may also collect and disseminate data on emission factors.

3. University-based researchers are another source of information on emission factors. Most academic

work is done in the engineering and environmental science disciplines. It includes activities such asmeasuring the emissions from prototype engines or boilers, testing equipment for emissions usingdifferent fuels, firing rates (the rates at which fuels are burned), and combustion conditions, and testingnew pollution-reduction technologies. University-based researchers are also responsible for many ofthe emission factor estimates for household stoves used in the developing world.

4. International and intergovernmental organizations, such as the United Nations Environment

Program (UNEP) and the World Health Organization, measure and collect emission factors to assessthe extent and severity of global and regional environmental problems. (GEMS, Environmental Data


Report) These organizations also provide databases, reports, and guides as a service to planners anddecision makers in their member countries. EDB itself is the product of a collaborative project betweenSEI and UNEP; the WHO's Management and Control of the Environment report provides anotheruseful compendium of emission factors and modeling techniques. The Intergovernmental Panel onClimate Change (IPCC) collects and disseminates information on emission factors for greenhousegases, including greenhouse gas emissions from the energy sector. Some of these emission factors--often based on factors from one of the sources above--are presented in the Greenhouse Gas InventoryWorkbook: IPCC Guidelines for National Greenhouse Gas Inventories, published jointly by the IPCCand the Organisation for Economic Cooperation and Development (OECD).

4.3 The Cause-and-Effect Relationship in Emission Factors

An emission factor links the amount of a quantity you know, e.g. the liters of diesel fuel used by amotorcycle, to a quantity you would like to know, e.g. the emissions of particulate matter by that vehicle.This presupposes a direct linear relationship between the two quantities, and that the former causes thelatter. Often there are also indirect links between emissions and the energy activity, which can be ofrelatively major or minor importance. Therefore, before proceeding to use or enter emission factor data, itis important to examine the nature of the relationship between the source and the emissions of concern anddetermine how the emissions are a direct and/or indirect result of the energy activity. In the case ofmotorcycle emissions for example, the relationship between the liters of fuel consumed and the emissions ofpollutants is both direct and indirect. While some hydrocarbons are emitted from the tailpipe, and are thusa fairly predictable direct function of the amount of fuel consumed, other hydrocarbons are emitted as oil inthe crankcase evaporates or is broken down by the high temperatures of engine operation. These emissions(known as "crankcase emissions") are a function of how the vehicle is used, but not necessarily how muchfuel is consumed. Another class of hydrocarbon emissions ("evaporative emissions") result as fuel in thegas tank evaporates to the atmosphere. Evaporative emissions may be a function mostly of the temperatureat which the motorcycle is stored. These distinct types of hydrocarbon releases can all be included in acoefficient describing overall hydrocarbon emissions from motorcycles, but to do so a number ofassumptions must be made, including the average duty cycle (the number of miles per trip, how fast themotorcycle travels, and how often it is used) and the average temperature at which the vehicle is stored andoperated. When this level of detail is considered appropriate all necessary assumptions should be clearlydocumented.

A second example is a coal fired smelting process, which refines raw materials such as copper oreinto primary metals such as copper. While some of the emissions from this process are a direct function ofthe amount of coal consumed, others, such as emissions of particular trace metals (say, vanadium), aremore strongly a function of the quantity of copper ore processed and the composition of the ore itself. Asa consequence, it would be erroneous to estimate a smelting process emission factor for vanadium that issolely dependent upon the tonnes of coal consumed. Similarly, the total emissions of carbon dioxide fromthe manufacturing of cement is not a straightforward function of the fuel consumed in the manufacturingprocess. The processing of limestone, typically a crucial raw material, produces a great quantity of CO2

independent of fuel consumption. As a final example the emissions from a petroleum refinery depend notonly on the fuel consumed by the various boilers and burners used, but on the types and relative amounts ofthe different petroleum products the refinery produces as well as on the types of crude oil and othersubstances used as raw materials in the refining process. Generic emission factors for such installationsshould therefore be used with caution.


4.4 Determining the Appropriate Units for Emission Factors

Even when emissions follow directly from the energy use of a specific activity for which data isavailable, emission factors are often not available in exactly the form needed for analysis. Before applyingemission factors in a planning context, entering emission factors into EDB, or developing emission factorsfrom test data, it is important to check the form of an emission factor, so that the units unambiguouslymatch those of the energy activity whose emissions or impacts are being estimated.

When specifying emission factors in EDB, it is necessary to distinguish between the actual unitsused, and the type of units used. For example, there are many different ways to express units of the masstype; milligrams, grams, kilograms or tonnes are examples of international units, while pounds and "shorttons" (2000 pounds) are English units. Conversion between these units is a relatively simple matter, and isaccomplished automatically in EDB, as long as the units are contained in EDB's list of common units. Thetype of unit is a more important choice, as noted below.

In most instances, selecting the type of numerator unit for an emission factor will be fairlystraightforward. Emissions to air and water, are typically measured (with the exception of radioactiveemissions) in mass units (e.g. grams, kilograms, or pounds), likewise solid wastes. The numerator unit foroccupational health and safety is dictated by the type of impact measured (injuries, deaths, lost work days).In other cases emissions or effects are measured in clear but (from the standpoint of estimating emissionfactors) incomplete units as when pollutant concentrations are measured instead of masses. If, forexample, methane emissions from combustion of biomass in a wood stove are reported as 3.2 ppm (parts-per-million), then you know the amount of methane relative to the amount of exhaust gas leaving the stove,but you do not know, without additional information (namely the amount of exhaust gas released per unitfuel, the temperature of the gas, and/or the amount of oxygen present in the gas), the amount of methaneemitted per unit fuel burned. Other difficulties in handling numerator units for emission factors arise forradioactive emissions. The most basic unit of radioactivity is the "Curie"" (Ci), which is equal to a certainnumber of radioactive disintegrations per second. Other units commonly used, including the "rad" and the"rem"87, depend on assumptions such as the distance an exposed person or animal is from the source ofradioactivity and the time of exposure, and thus must be evaluated carefully before being interpreted asemission factor estimates for general use.

It is often also necessary to determine if the factor should be specified based on the energy or fuelinput or whether on the process or energy output. In general, emission factors based on energy input aremore widely applicable, since output-based factors depend critically on process efficiencies, which can varysignificantly.

The emissions of carbon monoxide from a wood cookstove, for example, could be measured asgrams of CO per kg of wood consumed in the stove, or in grams of CO per kilocalorie of heat energysupplied to the cooking pot. Both forms are correct, but the emission factor based on input fuel is morebroadly applicable since, within limits, it can be applied to stoves that have different efficiencies from thestove for which emissions were originally measured. In contrast, emission factors based on energy output

87The "rad" and "rem" are measures of the dose of radiation that a radioactive source delivers to an absorbing material (e.g.human tissues). A rad is a measure of the amount of energy deposited per unit mass of the absorbing material, and is equal to10-5 Joules deposited per gram of absorber. A "rem", or "Roentgen Equivalent Man" (after German scientist W.K. Roentgen,the discoverer of x-rays) is equal to a rad times a factor called the relative biological equivalent, or RBE, which is a measure ofhow much damage the form of radiation is likely to do to the biological tissue that absorbs it.


would have to be accompanied by the efficiency of the stove in order to be properly interpreted and appliedto stoves of different efficiencies, since the amount of fuel used to produce a unit of output would differ.Similarly, data on emissions from vehicles are often specified in unit weight of pollutant per unit distancetraveled: grams per kilometer or grams per mile. In order to estimate emissions based on fuel inputs,assumptions on vehicle efficiency are needed (for example, liters of fuel used per kilometer traveled, orgallons of fuel per mile). Assumptions on vehicle efficiencies and the calculation of emissions per unit offuel input are included for many of the transportation-sector emission factors in EDB.

For other types of energy-transforming devices, it may be more convenient to describe an emissionfactor in terms of the energy or product output from the process. The production of crude oil is anexample. In general, the output of an oil well will be relatively easy to determine, thus it is natural tospecify emissions or impacts in terms of the barrels or tonnes of crude oil produced. Output-basedemission factors are also suited to processes such as coal mining, gas production, fuelwood collection, andwood milling.

When reviewing documents containing emission factors, it is important to check whether thefactors are measured on the basis of energy input or output. This will, in part, determine whether they canbe used directly with energy data, or whether they will need to be modified. Quite often, emission factorsfor power plants that use burnable fuels (such as biomass, oil, or coal) will be specified per GWhe, that is,per Gigawatt-hour of electricity. If one were to specify emission factors for power plants per unit fuelinput, say, in EDB, it would be necessary to find or estimate the efficiency of the power plant. For it ispossible to convert an output-based emission factor of 1000 te CO2/ GWhe by applying an electricitygeneration efficiency:

1000 te CO2/ GWhe * 0.34 GWhe/GWhfuel input = 340 te CO2/GWhfuel input,

or in Gigajoules (GJ):

340 te CO2/GWhfuel input / (3600 GJfuel input /GWhfuel input) = 0.094 te CO2/GJfuel input

In turn, this emission factor may need to be converted to indicate emissions per unit of physical input, suchas tonnes of coal or liters of diesel, as discussed below.

4.4.1 Physical vs. Energy Units

Choices also exist for the type of emission factor denominator unit. In EDB, users are encouragedto enter emissions or impacts in physical, units, that is, emissions per unit mass or volume of fuelconsumed. Alternatively, factors may be entered with denominators of energy units, for example, kg ofnitrogen oxides emitted per GJ (gigajoule) of natural gas consumed. When making the choice betweenphysical and energy units the following questions should be considered:

1. Is the emission or impact likely to scale (grow or shrink) with the energy input to the process, or withthe physical input of fuels? This is an especially important distinction in instances where the energycontent of a particular fuel type can vary substantially per unit mass or volume. An example is sulfuroxide (SOx) emissions per unit of coal consumed. Since SOx emissions typically depend on thequantity of sulfur per unit mass in the fuel, expressing a coefficient for this pollutant in, for example,kg of sulfur oxides per GJ of coal burned, could lead to errors if the energy or sulfur contents of thecoal being burned when the emission factor was measured are very different from the energy or sulfurcontents of the coal being considered. For example, say a coefficient indicates that 1.3 kg of SOx are


emitted per GJ of coal consumed, and this coefficient was measured in an industrial boiler using coalwith an energy content of 30 GJ/tonne and containing 1% sulfur. If the coal in your area also contains1% sulfur by weight, but its energy content is 15 GJ per tonne, then using the emission factor based onenergy units will understate the emissions of sulfur from combusting a tonne of coal by a factor of two.

Calculation Using Emission Factor in Energy Units:1.3 kg/GJ * (1 tonne * 15 GJ/tonne) = 19.5 kg SOx

Calculation Using Emission Factor Converted to Physical Units:(1.3 kg/GJ *30 GJ/tonne) * 1 tonne = 39 kg SOx

2. Is it possible to describe the source of the emission or impact unambiguously, that is, in such a wayas it can be understood with no additional information, using physical units? For example, considera power station fueled with low-quality lignite coal. The emissions of nitrogen oxides to the air canbe measured per unit mass of lignite burned, but to do so would not allow you--unless otherinformation was supplied--to apply this emission factor to other coal-fired plants. This is because theenergy content of low-quality coal can vary considerably from country to country and even mine tomine. This would be an instance where the denominator for your emission factors should be specifiedin energy units.

In EDB, emission factors for all "Demand" categories (stoves, industrial boilers, automobiles,furnaces, etc.) are specified per unit fuel input. There are general conventions as to which of the"Transformation" (electricity generation facilities, coal mines, petroleum refineries, biomass harvesting,etc.) categories have emission factors based on fuel input, and which are based on fuel output. Whencreating a new category you have the option of which specification to use88. Table 4.2 shows theinput/output conventions used in entering the EDB core data

88In addition to input and output, you can, when setting up EDB Transformation categories, specify that emissions from aTransformation process be proportional to losses of a fuel from that process. This option is typically used for technologiessuch as natural gas pipelines, where emissions of substances such as methane are more accurately specified relative to theamount of fuel lost during gas transportation, rather than the amount of gas entering or leaving the pipeline.


Table 4.2:Use of Physical or Energy Units for Emission Factors

LEAP

Program Device

Appropriate

Unit Type

Emission factor

specified per unit:

Sample Units

Demand End-use fuel-combustion equipment: coal,

oil, natural gas

Physical Fuel input kg CO/cubic meter gas

Demand Solar Space/Water Heaters or Cookers Energy Solar input or heat

output

GJ thermal energy

emitted/GJ solar energy input

Trans. Power plants burning coal, oil, natural gas Physical Fuel input kg fly ash/tonne coal

Trans. Geothermal, Hydroelectric, Nuclear, Solar

Photovoltaic Power Plants

Energy Fuel Input Curies of radiation/GJ

nuclear heat input

Trans. Distribution Losses Physical Fuel Losses kg VOC/liter of gasoline lost

during transport

Trans. Ethanol, Biogas Production, Charcoal

Production

Physical Fuel Output kg suspended solids (liquid

waste)/liter ethanol produced

Trans. Coal, Oil, Natural Gas Production Energy Fuel Output kg hydrocarbons/bbl oil

output

4.5 Measurement and Estimation of Emission and Impact Factors

All of the emission and impact factors in EDB and in other references are derived from measuredquantities such as emissions for test devices, estimated based on fuel composition or other parameters,calculated from available statistics, based on the judgment of researchers, or derived using a combinationof these techniques. An overview of some of the different approaches used to estimate emission factors isgiven below.

4.5.1 Measurement techniques

Many of the pollutant emission factors found in the literature are derived from samplemeasurements of emissions taken during tests of equipment. The types of equipment tested span the rangefrom wood stoves to nuclear power plants, and include technologies ranging from the experimental (such asprototype automobiles or fuel-cell electricity generators) to the well-established. A variety of differentkinds of tests and monitoring systems are used, depending on the type of emissions being investigated andthe media--air, water, or solid wastes--to which pollutants are emitted.

Emissions of pollutants to the air and water are measured or monitored using two basic techniques.The first is referred to as grab sampling in which, as the name implies, a sample of the gas leaving thecombustion chamber, smokestack, or exhaust pipe of the device being tested is "grabbed", or removed, intoa bottle, flask, or other gas-tight container. These samples may be evaluated within a few hours, or maybe reserved for later analysis. It should be noted, however, that different techniques for grab samples canyield different results, even if you are starting with exactly the same sample. Pollutants and other gas


constituents can be adsorbed to the walls of the sample container, or can react to yield a sample that, whenanalyzed, is different from the sample actually taken. An extreme case of a pervasive sampling anomaly,in this case one that caused a large number of emission factors to be called into question, was the error innitrous oxide sampling procedures described in Box 4.2 below. The second general method of empiricallymeasuring air pollutant emissions on-line monitoring. A sensor is placed in the stream of exhaust gasses (ora part of the gas stream is routed through a sensing apparatus) and the sensor and an associated datalogging device take and record continuous measurements during the testing period.

Box 4.2: Problems in Sampling Techniques: The Case of N2O Grab Sampling

Until about 1988, measurements of nitrous oxide, or N2O --an important greenhouse gas (seesection 2)--were made by taking grab samples from the exhaust stacks of equipment such as boilers, andevaluating them sometime later in the laboratory. This practice, however, was found to cause asampling error or "artifact". It turned out that in many samples, the (non- N2O) nitrogen oxides, sulfurdioxide, and water vapor contained in the sample, were reacting in a complex manner to form far moreN2O than was originally present in the sample, sometimes 50 to 100-fold more. This caused estimatesof global emissions of nitrous oxide from the energy sector to be much higher, for a time, than isprobably the case. Global estimates of the emission of nitrous oxide from fossil fuel combustion haverecently been revised downward by a factor of between 10 and 30 (Levine, 1992).

Both types of sampling have advantages and disadvantages. Grab samples allow a centrally-located laboratory to process a number of samples from different energy installations, devices, or areas,assuring consistency in sample evaluation and cost savings relative to the installation and maintenance ofexpensive and sophisticated monitors at many individual sites. Grab sampling can also be used in caseswhere it would be technically infeasible to install an on-line monitoring device. Care must be taken,however, that accepted sampling and storage methods are used, since, as noted above, changes in thetechniques used can drastically affect results. Also, samples taken must be representative of the air orwater effluent flows during normal operation.

On-line monitors are useful, particularly for large energy installations such as industrial boilers,power plants, and refineries, but their use also requires care. The exhaust stack of a power plant, forexample, is an unforgiving environment where high temperatures, abrasive soot particles, and corrosivegasses may rapidly degrade monitoring sensors or sampling equipment. If these devices are not checkedand calibrated (or replaced and calibrated) frequently, erroneous measurements can result. Note thataccurately calibrated equipment is also necessary for the measurement grab samples, but laboratoryenvironments (where the analytical devices used to process grab samples are typically found) are usuallyless stressful to machinery than individual installations at boilers, power plants and similar facilities.

Identification and quantification of air pollutants monitored by both grab-sample and on-linemeasurements rely on a set of analytical technologies. Some of these are described in Table 4.3.Whatever method of measuring air emissions is used, additional data such as the rate at which fuel is beingused by the device (the firing rate), the volume of gas passing through the stack, the amount of oxygen inthe gas stream, and the temperature of the gas stream at the sampling point are required in order to relatethe measurement, which yields the concentration of pollutant constituents in the gas, to the mass ofpollutant released per unit fuel burned. Similarly, for aqueous e missions, the flow rate of liquid effluentsfrom a process, the relationship of the effluent flow rate to the rate of fuel combustion and theconcentration of the pollutants in the effluent, must be known, before an emission factor based on the unitinputs or outputs can be estimated.Table 4.3:


Methods For Measuring Air And Water Emissions

Method Used for

Grab Sampling Wide variety of air emissions, both air and water

Gas Chromatography Wide variety of air emissions, both air and water

Mass Spectroscopy Wide variety of air emissions, both air and water

Infra-red Absorption Spectroscopy Wide variety of air emissions, both air and water

Ion-specific electrodes and meters Pollutants in liquids, salts, acids, and bases

Liquid Chromatography Pollutants in liquids, particularly organic emissions

Analytical Kits and Reagents Various applications

Traditional "Wet Chemistry" Water-borne pollutants, especially inorganic constituents

Solid waste emissions are typically measured using grab samples, which are subjected to one ormore of the analytical methods listed above. Radioactivity is often measured (on-line or in samples) with"Geiger Counters" or similar devices that "count"--in the simplest monitors by giving off a sound--whenever a radioactive particle of a certain type hits the monitor's detector. The rate at which "counts"occur indicates the extent to which the sample or area monitored is radioactive.

4.5.2 Emission Factors and Fuel Composition

A number of emission factors are estimated based primarily on fuel composition or on the way thatthe fuel is burned, rather than on the strength of empirical measurements like those described above. Thisis often true for emissions of carbon dioxide, sulfur oxides, and trace metals such as lead. EDB provides amechanism whereby an emission factor can be directly related to the carbon, sulfur, (as is applicable forCO2 and SOx) nitrogen or moisture content of a fuel, allowing for the entry of the actual percentage (byweight) of these elements in the fuel for which the emission factor was measured or estimated. Foremissions such as trace metals, this fuel composition option is unavailable, but it is important to enter thefraction of the trace constituent (if known) as part of the documentation notes in order to inform others whomight use your data as to the basis of the estimated emission factor.

Good examples of estimates based upon fuel composition are estimated emissions to the air ofcarbon dioxide (CO2) and sulfur oxides (SOx). When the sulfur and carbon in a fuel (coal, for example)are burned, that is, react with oxygen in the air, these two oxidized (in this case, oxygen-containing)compounds are produced. When combustion is reasonably complete virtually all of the carbon in the fuelwill be converted to carbon dioxide (usually about 98 to 99 percent for fossil fuels89). Likewise virtuallyall of the sulfur in a fuel will typically be oxidized to SOx though some may remain as elemental sulfur (S)in ash or in fly ash (the ash that leaves the combustion area in the exhaust gasses as tiny particles of soot).Actual sulfur oxide emissions to the atmosphere may be modified by pollution control equipment. Forinstance, a scrubber may capture 90 percent of the SOx leaving the combustion chamber of a boiler. In this

89One notable exception here are emissions from internal combustion engines, most frequently older cars and trucks. In somecases emissions of the partially-oxidized product carbon monoxide (CO) can account for a substantial--though still not major--fraction of the total carbon in the fuel. It should be noted that Although CO is an important pollutant from the standpoint oflocal air quality, the distinction between CO and CO2 emissions is of limited importance if you are estimating the emissions ofgreenhouse gases, as CO is oxidized to CO2 in the atmosphere relatively quickly. The IPCC Greenhouse Gas InventoryWorkbook lists default factors for the incomplete oxidation of carbon in fossil fuels ranging from 1 percent for oil and oilproducts to 2 percent (and higher) for coal (IPCC/OECD, 1993).


case net emissions to the atmosphere would be 10 percent of the total SOx leaving the boiler. Examples ofhow emission factors for carbon dioxide and sulfur oxides can be calculated, based on a knowledge of thecomposition of the fuel, are given in Boxes 4.3 and 4.4 below, and Box 4.5 gives additional detail on howthe CO2 emission factors in EDB were calculated.

Box 4.3: Sample Calculation of CO2 Emission Coefficient: Kerosene Stove

Initial Data and Assumptions:• Kerosene assumed to be 85% carbon by weight.• Estimated fraction of carbon oxidized: 99%• Ratio of weight of CO2 to C: 44/12 (molecular weight of CO2)/(molecular weight of C)

Calculation:0.85 kg C/kg fuel x.99 kg C emitted/kg C fuel x 44/12 kg CO2/kg C = 3.09 kg CO2/kg fuel, or3.09 kg CO2/kg fuel x 0.81 kg/liter (density of fuel) = 2.5 kg CO2/liter kerosene.

Box 4.4: Sample Calculation of SOx Emission Coefficient: Industrial Boiler

Initial Data and Assumptions:• Sulfur content of coal assumed to be 3% (by weight).• Estimated fraction of sulfur emitted as SOx: 95%• Ratio of weight of SOx to S: 64/32 (molecular weight of SO2)/(molecular weight of S)• Efficiency of SOx scrubbing system: 90%

Calculation:0.03 kg S/kg fuel x .95 kg S emitted/kg S in fuel x 64/32 kg SOx/kg Sx (1 - .9) SOx not scrubbed/total SOx = 0.00285 kg (2.85 gm) SOx/kg coal.

Calculations of emission coefficients based on fuel composition are useful when you lack anemission coefficient corresponding to a specific end-use device, but want to include at least approximateemissions from that device in emissions accounts. For example, few measured emission factors forkerosene lamps are available, but emissions of CO2 from these devices--which are important householdappliances in many parts of the world--can be estimated fairly readily. The same approach is sometimesuseful for other types of emissions, including emissions of ash from boilers fired with solid fuels (coal,wood, municipal solid wastes) or heavy oils, and the emissions of trace metals such as mercury, cadmium,or lead (found in coal). Like CO2 and SOx, these emissions of these substances are often a fairlystraightforward function of fuel composition.


Box 4.5: Preparation of CO2 Coefficients for EDB

The following procedure was used to establish a consistent set of coefficients for carbon dioxideemissions in EDB. First, a set of carbon contents by fuel was compiled from the literature90 and, insome cases, by calculations based on fuel molecular weights. Next, these carbon fractions weremultiplied by the ratio of CO2 to carbon molecular weights (44/12) and by an assumed average fractionof fuel that goes through burners unoxidized. The “unburned” fraction of fuel carbon (assumed to beprimarily emitted as soot and ash) was estimated to be 1.0 percent for each type of fuel (that is, 99percent of the carbon was assumed to be combusted). While this assumption is consistent with literatureestimates (e.g. Grubb, ibid.; OECD, 1991, Background Document for the February, 1991 Workshop onEmissions Methodology, Chapter 2: "Emissions from Energy Production and Consumption"), very littlerecent empirical work appears to have been done to quantify the fraction of carbon left unoxidized in sootand ash after fuel combustion. For types of fuel use (e.g. automobiles, wood stoves) where COemissions represent a significant (c. 0.5 percent or greater) fraction of total carbon emissions, thefraction of carbon emitted as carbon monoxide was subtracted from the CO2 emission coefficient. Thisavoids the problem of double-counting carbon emitted as CO. The table below shows the fuel carbonand energy content assumptions used in EDB, as well as the carbon dioxide emissions (assumingcomplete combustion) per unit fuel energy.

CARBON AND ENERGY CONTENT ASSUMPTIONS, AND CO2 EMISSIONS PER UNIT ENERGY91.

FUEL CARBON CONTENT ENERGY CONTENT kg CO2/GJ

NATURAL GAS 0.51 kg/m3 0.03545 GJ/m3 52.8GASOLINE 84.6 % by wt 43.96 GJ/tonne 70.6KEROSENE/JETFUEL 85 % by wt 43.2 GJ/tonne 72.1DIESEL/GAS OIL 86.5 % by wt 42.5 GJ/tonne 74.6RESIDUAL/FUELOIL 84.4 % by wt 41.5 GJ/tonne 74.6LPG/BOTTLED GAS 82 % by wt 45.54 GJ/tonne 66.0CRUDE OIL 83.5 % by wt 41.87 GJ/tonne 73.1COAL BITUMINOUS 74.6 % by wt 29.31 GJ/tonne 93.3COAL LIGNITE 31 % by wt 11.3 GJ/tonne 100.6FIREWOOD 43.8 % by wt 16 GJ/tonne 100.4ETHANOLa 52.2 % by wt 0.0219 GJ/l 110.8

a Ethanol and Methanol carbon contents converted to CO2/GJ using densities of 0.789 and 0.796 kg/l, respectivelyb This table shows only gross CO2 emissions from fuel consumption, and does not include CO2 impacts from fuelproduction (for example, CO2 produced when hydrogen is made from coal)c Based on “net” or “lower” heating values.

Emission factors for devices that use fuels whose compositions vary widely must be interpreted andused with care. Solid fuels--especially coals and biomass fuels--have the most variable composition; themoisture content, ash content, and heating value (the energy released when the fuel is combusted) can varywidely from place to place and sample to sample. These differences often effect how relatively "clean" or"dirty" a particular fuel is. A familiar example is the smoky fire (implying high emissions of particulatematter) that results when wet wood is burned, while drier wood burns more cleanly. Wood that is high in

90 Major sources for carbon contents included Grubb, M., 1989; "On Coefficients for Determining Greenhouse Gas Emissionsfrom Fossil Fuel Production and Consumption", P. 537 in Energy Technologies for Reducing Emissions of Greenhouse Gases.Proceedings of an Experts' Seminar, Volume 1, OECD, Paris, 1989, and ORNL, 1989; Estimates of CO2 Emissions from FossilFuel Burning and Cement Manufacture..., G. Marland et al of Oak Ridge National Laboratory, May 1989, ORNL/CDIAC-25.91 This is possible because petroleum is 80-85 percent carbon and most (32/44) of the mass of CO2 comes from oxygen, whichis principally derived from the air in which the fuel is combusted, and not from the fuel itself. Note that the CO2 coefficientsas derived here are slightly different (usually no more than a percent) than the factors presented in the IPCC Greenhouse GasInventory Workbook (IPCC/OECD 1993). This variation is well within the variation of fuel carbon contents.


pitch (a softwood such as pine, for example) may burn hotter, increasing emissions of NOx. Emissionfactors in the literature (or in EDB) may need to be modified if practices for drying or otherwise treatingwood or other fuels differ substantially from those used when the emission factor was measured. It isnecessary, therefore, to consider whether the fuels under consideration are in important respects "cleaner"or "dirtier than the fuels for which emission factors are described in the general literature (including EDB).Some characteristics that cause fuels to be described as "clean" or "dirty" are presented in Box 4.6.


Box 4.6: "Dirty" vs. "Clean" Fuels

Natural gas is often touted as a clean fuel because very little or no smoke (particulate matter) isproduced when it burns. It also produces less carbon dioxide per unit fuel energy. Even within types offossil fuels there are differences. The petroleum product residual oil, for example, is much higher insulfur and ash--yielding higher emissions of particulates and sulfur oxides when it burns--than the morerefined products diesel fuel, kerosene, and gasoline (or petrol). Even among gasolines, which arecomplex blends of many different hydrocarbon species, there are cleaner and dirtier grades. It is fairlywell known how the composition of gasoline can affect performance of an engine (and thus itsemissions), witness the availability of "super" or "premium" grades. In the United States and othercountries, there are also gasolines that are made cleaner by limiting or prohibiting the use of lead as anadditive. In addition, special gasoline formulations have been developed that reduce the evaporation offuel from the fuel system of automobiles, and thus reduce some of the urban air pollution problemsassociated with evaporative hydrocarbon emissions.

From a greenhouse gas standpoint, biomass-derived fuels, as a class, are often considered"clean" because their combustion--when they are produced sustainably --is not accompanied by a netrelease of carbon dioxide. When other emissions are considered, however, biomass fuels do notalways fare well in comparison with other alternatives. For indoor air quality fossil fuels are generallypreferred over biomass fuels (for example, use of electric or kerosene cook stoves instead of biomass-fueled units). Among the biomass fuels, charcoal typically burns much more cleanly--with less productionof particulate matter and carbon monoxide--than do wood, crop residues, or animal dung. Theproduction of charcoal, however, has associated environmental impacts at the kiln site, and also requiresmore wood input per unit fuel output, thus affecting more land, than other fuels92. The figure below(after Smith, 1987) shows schematically the relationships between fuel use by type of emission, comfort,and household income.

Time, Income, Cost

Non-Commercial Fuels Commercial Fuels

Wood

Crop Residues

Dung

Kerosene

Gas

Electricity

MinimumBasic Need

Comfort

Emissions

92The emissions and other impacts of charcoal production, for example, are concentrated at the site of charcoal production, andthus have little impact on the indoor and local air quality in the places where cooking fuels are used. From a national orregional point of view, however, these impacts can be quite important.


Box 4.6: "Dirty" vs. "Clean" Fuels (cont.)

Biomass-based fuels, particularly methanol (CH3OH) and ethanol (C2H5OH), have generatedconsiderable interest and substantial activity over the last two decades as motor-fuel substitutes forgasoline. Methanol and ethanol generally burn more cleanly--produce generally lower emissions perunit energy--than gasoline, but most existing internal combustion engines must be modified in some wayin order to accept these fuels if they are used alone. Another approach has been to blend alcohol fuels,usually ethanol, with gasoline to create "Gasohol" a fuel that can be consumed in most existing engines.Some gasohol blends, however, can promote the evaporation of hydrocarbons from the fuel tank, so it isnot possible to state that use of these fuels will lead to lower emissions in all cases.

The composition of coals vary widely depending on their rank (which describes their fuel valueand geological origin), where they are found and how they are treated prior to combustion (if at all).Different coals have a wide range of sulfur, ash, moisture, and energy contents. Anthracite coals, forexample, though relatively rare, typically are low in sulfur and burn hot and clean. Bituminous coals, themost common type used in industrial boilers, for electricity generation, and in household applications (insome countries) vary across a wide range of compositions. Lignite, or "brown" coal, as is found in, forexample the region formerly known as East Germany and in Poland, is typically high in ash andmoisture, and has a relatively low energy content. Brown coal often burns inefficiently and withrelatively high particulate emissions. In many countries, coals are "cleaned"--often by pulverizing themto a powdered form and washing to remove ash and sulfur--before they are burned. This processpromotes better combustion, but the reduction in air emissions that may result is likely to becounterbalanced by an increase in solid wastes, such as sulfur-containing sludge, that must be disposedof. This type of trade-off points up the need to examine the entire fuel cycle, to the extent possible,when evaluating the environmental impacts of energy alternatives.

Hydrogen is often touted as the ultimate "clean fuel", because its sole direct combustion productis water vapor, which is rarely considered a pollutant. However, hydrogen combustion in air can emitnitrogen oxides as molecular nitrogen (N2) from the air combines with oxygen in the flame. Apart fromthe difficulties in handling and storing hydrogen gas, many of which are being overcome as technologiesimprove, it is important to consider the "upstream" impacts of hydrogen use. Hydrogen can be producedby a variety of different methods and from a variety of different feedstocks. If hydrogen is producedfrom coal, the impacts from the production phase of the fuel cycle may counterbalance the benefits ofhaving a clean-burning end-use fuel. If, on the other hand, hydrogen is made by electrolysis93 usingelectricity from (for example) photovoltaic panels, then the sum of impacts over the entire fuel cycle maybe minimal.

4.5.3 Emission Factors and Fuel Combustion Conditions

Emissions of some types of compounds (typically atmospheric emissions) are particularly sensitiveto the conditions under which fuel combustion takes place. Examples include the relationships betweenNOx emissions and combustion temperature, and between CO and hydrocarbon emissions and the ratio ofoxygen to fuel that is present. For certain classes of devices, emissions are modeled as functions of, forexample, the ratio of air entering the combustion area to fuel input, the temperature of combustion, and theamount of moisture in the fuel. These types of calculations can estimate emissions where monitoring is notpossible or is too expensive, or to estimate the emissions from new conceptual or prototype devices (suchas new car engines) before the devices have been built. These techniques are typically used by mechanicaland chemical engineers, and are also used in more sophisticated emissions modeling frameworks such as

93The electrochemical process of splitting water (H2O) into molecular hydrogen and oxygen by applying an electric currentacross two electrodes that are immersed in a container of water.


the European CORINAIR project to track acid gases and other air pollutants (Corinair, 1992), and the“MOBILE” series of motor vehicle emission models used in the United States.

The fact that emission factors can vary with fuel combustion conditions means that when you useemission factors you must be aware of and note the conditions under which they were measured and areapplicable, and make sure that your use of them is consistent with the way in which they should be applied.You may, in some circumstances, need to use more sophisticated modeling approaches to estimate emissionfactors that correspond more directly with the technologies in your country than the generic factors that areavailable in EDB.

4.5.4 On-Site Impact Coefficients Based on Statistical Analyses

Some of the types of on-site impacts of energy technologies are not measured per se, but areestimated based on available statistics. In EDB, and in compendia such as the World Health Organizationguide (WHO, 1989), factors that relate quantities such as injuries, deaths, worker-days lost, and accidentsto the amount of energy or fuel produced or consumed by an energy technology are available. Examples ofthese factors are deaths from underground coal mining per tonne of coal, injuries per barrel of oil recoveredduring oil drilling, or accidents resulting from felling trees for firewood. Since these quantities typicallyoccur at too low a rate to be measured by an on-site observer, they are estimated based on aggregateindustry statistics. An estimate of coal mining deaths per unit coal mined, for example, might becalculated by summing all of the reported deaths from the types of coal mines being considered (theimpacts of surface and underground mining would be treated separately) that occur in a country or regionover a period of time--often many years--then dividing by the amount of coal produced by those mines overthat time span. Similarly, to estimate the probability of a sea-going tanker accident resulting (directly orindirectly) from oil use, you would sum the reported tanker accidents over the last decade, and divide themby the tonnes of oil transported by sea over the same time period. The accident statistics needed for thistype of analysis are often available from international sources such as the United Nations or the WorldHealth Organization, from national departments or ministries of labor or commerce94, from labor unions,or directly from firms in the specific industries. These statistics should be used carefully, as they typicallyonly represent reported accidents and events. If under-reporting is significant, the impact factors derivedwill underestimate the ultimate impacts of the energy technology.4.5.5

4.6 Determining the appropriate emission factors to use

The major challenge for the energy analyst is to pick the appropriate emission factors from themany (or few) available options for a given energy technology. Quite often, as in EDB, the variety ofdifferent "sources", or types of equipment, for which emission factors are listed may seem daunting; how doyou, if you are not very familiar with the field, choose the most appropriate option? At the other extremespecific data may unavailable, with references listing only very aggregate figures. How do you judge ifthese are appropriate for your application? In the following subsection we address these questions.

94In the United States, the Occupational Health and Safety Administration (OSHA) is responsible for keeping many of thesestatistics.


4.6.1 Choosing an Appropriate Set of Emission Factors from the Options Available

Emission factors in the literature--and, as a result, in EDB--are of several types. Some describeemissions from a general sources, such as "Industrial Sector Coal Combustion", others describe sectoralemissions from a general source but for a specific area, such as "Industrial Sector Coal Combustion,Germany". Alternatively, they may describe emissions from a specific device, like "Spreader-Stoker-typeIndustrial Boiler, Bituminous Coal-Fired, Wet Limestone Slurry Scrubber Used for Emissions Control".You will find all three types of emission factors in EDB, and sometimes there will be many more than onechoice for a sector, subsector, end-use, or device that you wish to model.

If you are looking to model a general source of emissions, such as all oil combustion in thecommercial sector, and lack the data necessary to break oil use in the sector down to the subsectoral or enduse level, you may wish to choose a “generic” emission factor. Generic emission factors are designed to bebroadly, if roughly, applicable to a variety of situations, or to act as first-cut estimates until more specificemission factor estimates can be found. If the factors that you are considering are for a genericinternational sector, you need to consider what assumptions underlie the factors. Are the estimates basedon international statistics, and if so, from what countries were data included? Alternatively, were theestimates chosen as subjectively-representative by those compiling the emission factor database orcompendium? The answers to these questions may affect your decision to use a set of generic internationalfactors.

Emissions coefficients defined for a single country or region are also available. Before using thistype of estimate, one should consider if the energy device/process in the area under study is similar to thoseused in the area for which the estimate is available. If detailed information on energy use is available, andeven at times when it is not, the best approach is often to choose from among emission factors specific toparticular devices. For example, if coal-fired boilers in your country are typically of the spreader-stokertype, an emissions "source" using that technology would be appropriate for coal combustion in industrialboilers. Even if you are unfamiliar with a particular technology, you can ask a colleague, or call engineersat industrial plants to ask what their experience has been.

The goals of a study partially determine the level of effort devoted to the selection of emissionfactors. If, for example, the primary goal is to estimate carbon dioxide emissions from coal use, andinvestigation of EDB and other databases shows that there is relatively little difference between theemission factor sets for other emissions, such as ash, associated with the technologies in question, then thechoice of one particular ash emission estimate over another is not critical and the choice can be madequickly. For a pollutant central to the objectives of a study, or for one whose emissions per unit fuel inputvary substantially from estimate to estimate it may be necessary to spend more effort on determining therange of values and picking the source that seems most appropriate.

4.6.2 Using Available Sets of Emission Factors to Provide a "First-Cut" Estimate

Sometimes available data on emission factors is inadequate. In such cases, one option is todetermine the most closely-related emissions estimate from the available databases and either to use thisunmodified, or modify it to better suit your application, noting your assumptions under either circumstance.The basic approach is to use common sense, augmented with a knowledge of the relevant energy-usetechnologies. If, for example, you need an estimate for the emissions of a commercial furnace that burnscoconut shells and no coconut shell fueled devices are listed in the available references, you might useestimates for a similar furnace burning a different type of biomass fuel, say field crop residue or wood, as a


proxy until more specific information becomes available. Similarly, a set of emission factors for akerosene stove might be a good stand-in to apply to kerosene heaters. What you are looking for first aresimilar fuel types: gas, solid, or liquid, biomass or non-biomass. Then try to select the best option fromamong the devices available.

A different type of problem arises when equipment burns the same fuels as equipment described inEDB or elsewhere, but is substantially different, due to age, maintenance (or lack of same) or design.Automobiles are a good example. In many countries in Latin America, as around the world, vehicles areequipped with fewer emission controls, and generally are not as well maintained, as in Europe or the UnitedStates. Assuming that (as in EDB) much of the emission factor information in this sector is based onvehicle stocks in industrialized countries, it might be appropriate, for the purposes of estimating emissions,to model the average 10-year-old vehicle as being equivalent to an average 20-year-old car, truck or bus inthe U.S.

Finally, there may be cases where emission factors for an energy technology simply do not exist inEDB or elsewhere. In some cases, however, the technology--perhaps a technology that is relatively new oruntried--is similar enough to an existing technology to allow one to reasonably assume that theenvironmental emissions or impacts of the two technologies should be similar. Examples are facilities forproduction of fuel ethanol or methanol. Since there have been centuries of experience with fermenting anddistilling ethanol products from biomass feedstocks (e.g. the liquor industry) and with making methanol foruse as a solvent and chemical feedstock, it would not be unreasonable to assume that many of the sametechnologies, with their associated emissions and impacts, would be used in making fuel alcohols. Thisassumption provides a starting point for estimating the emission/impact factors associated with the newindustries. In these types of comparisons it is important to make sure that you are (when possible)comparing technologies of similar scales, and that you are comparing effects on a per unit basis. A 10thousand tonne per year ethanol distillery, for example, may not have the same emissions or impacts pertonne of product as a one million tonne per year fuel ethanol plant, and it would be inappropriate to directlycompare a reactor used in a methanol plant to a petrochemical plant three times as large.

4.6.3 Combining Emission Factors from Different Sources, and Modifying Existing Emission Factors

Sometimes emission factor estimates from more than one source differ from each other, and yetappear equally valid for the situation being studied. After examining the derivation of each estimatecarefully and reviewing, to the extent possible, the reasons they differ, it may be reasonable to take anaverage over the data sets. Alternatively, you may need data on several types of emissions from a singlesource but find that only a few emission factors are available. In this case one approach is to use theemission factors from several different source categories, perhaps averaging where more than one factorexists for an emission, in order to develop a composite source. A composite factor set will, of course, beonly approximate, and should be replaced by more source-specific measurements whenever possible.

Combining sets of emission factors into a composite value may also be appropriate when severaldifferent types of processes occur within a single subsector, but sufficiently detailed energy data todisaggregate the activities is not available. If, for example, you estimate that 20 percent of the autos in acountry correspond to one emission factor and 80 percent correspond to another, but you only have totalgasoline consumption figures and don't wish to, or can't, separate consumption by auto type, then a singleestimated emission factor set can be created by calculating a weighted average. In instances whereemission factors for the same pollutant exist in both sets of factors, multiply the first set by 0.2, and thesecond set by 0.8.


You may also encounter cases where the equipment is slightly different than that for which youhave emission factors, but where simple adjustments can be made to reflect those differences. Accountingfor the efficiencies of different types of emission control systems is one example. Many of the coefficientsin EDB describe pollutant emissions for equipment without emission controls. If, for example, industrialcoal-fired boilers in your country are required to use electrostatic precipitators or similar technologies toremove particulate matter from the exhaust gas stream, then an emission factor for the boiler can beestimated by taking the base (uncontrolled) emission factor for particulate matter and multiplying it by 0.01(assuming that the electrostatic precipitator collects 99 percent of the particulates). In some cases emissioncontrol equipment affects emissions of more than one pollutant, though often not in the same proportions.Typically, not all pollutants will be reduced by a single control technology, and some emissions may evenincrease slightly as others decline.

4.6.4 Limits and Pitfalls of these Approaches to Emission Factor Estimation

The above methods are designed only to provide approximate values that serve until moreinformation is available. You can reduce possible errors in assignment or modification of emission factorsby learning as much as possible about the energy system for which you wish to estimate emissions and thederivation of the available emission estimates. While an obvious possible error associated with theapproaches listed above is to assign emission factors that are much too high or low, a less obvious butpotentially more serious problem is that by creating placeholder values and inserting them into thecalculations you may be institutionalizing them. That is, the next analyst who uses your numbers mayassume that they are based on better data than is actually the case, and will use them without properlyreviewing new information or data sources. It is therefore critical to clearly document all of theassumptions that you make in assigning, modifying, and using emission factors, carefully noting whereguesses or approximations have been made and where more research is necessary. Even if you have tomake many assumptions to derive an initial emission factor data set, however, the effort is worthwhile,because you are 1) providing a starting point that future energy/environment analysts can build on, and 2)you are contributing to the process of developing well informed energy and environmental policies.


4.7 Uncertainty, Errors and Limits of Applicability

The uncertainties associated with the emission factors listed in EDB and elsewhere vary greatlyamong pollutants. Estimates of fossil fuel CO2 emission factors are primarily dependent on fuel carboncontent, and thus usually have relatively little variability, particularly for petroleum products and naturalgas. Carbon dioxide emission factors can probably be considered accurate to within approximately 5 to 10percent, as the carbon contents of fuels, particularly fossil fuels, do not vary widely. Other emissionfactors are often based on the results of a relatively small number of tests of fuel use in particular types ofequipment. In order to ascribe emission factors to specific sectors or subsectors of the energy economy it isnecessary, as noted above, to make a number of judicious assumptions. As a result, it is difficult to assignan uncertainty to all estimates of emission factors, as the accuracy of the factor will vary with how and forwhat the emission factors, which are estimates themselves, are applied. Increased emissions testing in boththe developing and industrialized world, with centralized international reporting of results, could helpgreatly in reducing these uncertainties and in expanding the range of emission factors available as well astheir accuracy, as discussed below.

Until a large range of accurate emission factors is available, one measure that you, the analyst, cantake to evaluate the effects of uncertainty in emission factors on your emission estimates is to use the rangeof available emission factors--for example, high and low values for a particular pollutant and energytechnology--to calculate high- and low-case pollutant loadings. The way that you would carry out this sortof sensitivity analysis using LEAP and EDB is to “link” different EDB sources, with high and low-caseemission factors, to your LEAP Demand devices and Transformation processes.

4.7.1 Validity of Emission Factors based on Empirical Tests

The validity of the emission factors you find in the literature, and of those you measure yourself, isa function of the way in which the empirical data used to estimate the factors were collected. Some of theagencies that estimate emission factors, including the U.S. Environmental Protection Agency (USEPA), usea system to rate the "reliability" of emission factor estimates. The USEPA's rating system uses the lettersA through E; factors rated "A" are considered the most reliable, while factors rated "E" are probably at bestindicative, and are not to be used for rigorous work. The sampling procedures used, the number of testsdone, and the range of equipment sampled all contribute to the reliability of an emission factor. Table 4.4provides a sampling of sources of emissions and the emission factor ratings that the USEPA has assignedto pollutant emissions from these sources. Note that these vary widely across pollutants and sources.

Applying an emission factor based on a limited number of tests or a limited range of samples is theonly course available under some circumstances, but it should be recognized that the emissions estimatesproduced with such a factor will be uncertain. You may often find that an emission factor in the literatureis based on tests of only one or a few models of a certain type of device, recognizing this you should use theestimate with caution, as you probably don't know for sure how well the characteristics of the test devicesmatch the category of devices for which you are trying to model emissions.


Table 4.4:Sampling of USEPA Emission Factor Ratings for Various Energy Technologies

USEPA Emission Factor Ratings By Type Of EmissionSource Description SOx NOx N2O CO2 CO Partic. CH4 TOC*Pulverized Bituminous CoalBoiler, Dry Bottom

A A D A A B B

Overfeed Stoker BituminousCoal Boiler

B A E B C B B

Hand-fed Bituminous Coal Boiler D E E E E E EFluidized Bed Bituminous CoalBoiler (Bubbling Bed)

E D E D E E E

Utility Boilers--Residual Oil A A A A A AResidential/CommercialFurnaces/Boiler, Distillate Oil

A A A A A A

Industrial Boilers--Natural Gas B A D A B C CLPG Combustion (All) E E E E E EBagasse-fired Boilers C A CResidential Fireplaces A C C B B DResidential Wood Stoves B C C B B E ENatural Gas-Fired Turbines B C B D E D DLarge Diesel/Gasoline Engines D D B D D D* Total Organic Compounds. For some sources, ratings in this column refer to volatile organic

compounds.Source: USEPA document Compilation of Air Pollutant Emission Factors, Volumes I and II (plussupplements). USEPA, Washington, D.C., USA. This document is commonly referred to by its reportnumber: AP-42. Information in the table above is derived from a 1995 updated to AP-42.

4.8 Categories of emission factors particularly sensitive to local conditions

4.8.1 Household stoves

Demand for biomass fuels, typically used in household stoves, can be a significant contributor toproblems of land degradation, soil erosion, and ecosystem damage. In addition the extensive use oftraditional cooking fuels and equipment, may pose considerable health risks, particularly to women. Forexample, very high concentrations of carbon monoxide (940 ppm) have been reported for households inLagos, Nigeria. (Smith et al, 1983, as reported in Adegbulugbe, 1992). Emission factors for biomassstoves are especially sensitive to local conditions for several reasons. First, biomass fuel characteristicsvary from country to country, region to region, house to house, as well as temporally from season to seasonand even day to day. What is burned may depend on what is foraged--wet wood one day, dry wood thenext, bark, crop wastes, or manures at other times, and possibly even charcoal or coal. Each fuel has itsown specific characteristics (density, levels of ash and moisture, size) and composition, leading to differentcombustion characteristics and different levels of emissions of specific pollutants. Second, there are awide variety of wood stove designs, from the simple three-rock stoves to the newer fuel-efficient models.Stoves are typically built with local materials, which further increases the variability of their performance.People in different countries operate stoves in different ways, depending on cooking customs, local cuisine(some foods must be heated rapidly, while other foods demand a steady but low source of heat over anumber of hours) and on secondary uses of the stove, such as space heating and insect control (by smoke)in the thatched roofs of cottages. Even differences in fire and stove management from household to


household, or within the same household over time can be significant. Each source of variabilitycontributes to make "standard" emission factors difficult to determine. Given the importance of emissionsfrom household stoves in contributing to both indoor and local air pollution, this sector is a good candidatefor an active international research and an emissions testing program.

Table 4.5:SAMPLING OF EMISSION FACTORS FOR HOUSEHOLD STOVES

Type Region Source Unit CO2 CO CH4 HC NOx SOx(a) TSP N20WOOD

Default Senegal Best guess g/kg 1420 100.0 9.0 7.5 0.8 0.5 10.00 0.06Manila Phil. Smith 1992 g/kg 1620 100.0 9.0 13.0 0.06Manila (5% C in ash/TSP) Phil. Smith 1992 g/kg 1560 99.0 8.0 12.0 0.06Generic wood stove ------- Ellegard 1989 g/kg 1400 121.0 3.9 0.8 0.4 11.40Generic tropical wood stove ------- Smith 1987 g/kg 1460 80.0 7.5 0.7 0.6 9.00Chula 1 India Smith 1987 g/kg 1460 72-92 4.2-9.9Chula 2 India Smith 1987 g/kg 1480 66-76 8.7-9.13 stone fire Smith 1987 g/kg 1460 39-106 2.9-15Metallic stove Smith 1987 g/kg 1560 13-22 1.3-2.6Tara ("improved stove") Smith 1987 g/kg 1540 23-37 1.1-2.5CPS ("improved stove") Smith 1987 g/kg 1490 48-67 1.8-3.8CPRI ("improved stove") Smith 1987 g/kg 1420 86-113 0.3-8.3

CHARCOALDefault Senegal Best guess g/kg 2760 247.0 8.0 4.0 0.7 2.40 0.06"Haiti" Haiti Ellegard 1989 g/kg 2780 264.0 0.7 2.40Manila Phil. Smith 1992 g/kg 2740 230.0 8.0 4.0 0.06

LPGDefault Senegal Best guess g/kg 2950 24.0 0.0 3.0 2.0 0.0 0.06 0.03Manila Phil. Smith 1992 g/kg 3110 24.0 0.0 3.0 0.03All-purpose, generic, uncontrolled ------- USEPA 1985 g/kg 2980 0.4 0.1 0.2 2.0 0.0 0.06

KEROSENEDefault Senegal Best guess g/kg 3010 50.0 1.0 11.0 0.6 17.0 4.00 0.05Manila Phil. Smith 1987 g/kg 3030 38.0 1.0 11.0 0.05Kerosette-type stove Smith 1987 g/kg 2980 67.0 5.00Nutan Smith 1987 g/kg 3030 41.0 2.80Generic furnace WHO 1982 g/kg 3090 0.3 0.4 2.3 17.0 3.00Radiant stove Smith 1987 g/kg 3090 4.5 0.6 0.02Convective stove Smith 1987 g/kg 3090 0.0 0.1 0.02Multistage stove Smith 1987 g/kg 3090 0.1 0.1

OTHER BIOMASSCoconut husk stove Smith 1987 g/kg 1220 110.0 35.00Dung

COALGeneric DC coal stoves USEPA 1989 g/kg 2550 1050.0 0.0 5.2Handfired bituminous Ellegard 1989 g/kg 2630 48.5 4.0 15.8 2.9 14.6 10.80Handfired anthracite Ellegard 1989 g/kg 2830 138.0 5.8 0.9 13.3 0.70Mafalfa Ellegard 1989 g/kg 2580 80.0 5.9 6.0 12.2 2.00Maxaquene Ellegard 1989 g/kg 2530 112.0 1.1 3.4 7.2 6.30Indian stove Smith 1987 g/kg 2520 120.0 10.0 2.0 10.0 1.20

NATURAL GASGeneric cooking g/cubic meter1850 9.8 0.2 0.4 0.02

Blank entries indicate no data are reported for that pollutant. (a) SOx emissions will depend on S content of local fuel used.

A sampling of a number of emission measurements for household biomass and fossil-fueled stovesare given in Table 4.5. These measurements have primarily been made for small Asian stoves, but includethe results of recent tests of small household stoves that indicate emissions of previously unmeasuredgreenhouse gases (CH4, N20, etc.) could be very high (Smith et al., 1992) have also been incorporated.Combining these estimates with other emission estimates for "generic stoves", we have forwarded ourcurrent "best guess" or “default” estimates for these devices, which are also shown in the table below.


4.8.2 Vehicles

Transport sector emissions are a major source of urban air pollution. In Asian, Latin American,and OECD cities, motor vehicles generally account for about 90% of CO emissions, and often a largemajority of HC and NOx emissions. (Faiz, 1991) While not yet approaching the problems found in majorcities in Asia and Latin America, urban air quality problems related to transport emissions (vs.household/industrial emissions) are also of increasing concern in many African cities. For example, highlevels of CO and SO2 have been measured in Ibadan City, Nigeria, and typical haze and eye irritation areindicative of high levels of photochemical smog on major transportation routes in Lagos (Adegbulugbe,1992). In addition, leaded gasolines pose health risks, particularly to small children who breathe the airwith higher lead concentrations found at or near tailpipe heights. These health concerns are shared in mosturban areas of the world, with Manila, Bangkok, and Mexico City being notable examples.

Transport sector emissions depend on a variety of factors: vehicle type and emission controls, fuelcharacteristics, maintenance level, fleet age, and driving conditions. It is thus very important to take thesefactors into account in deriving and applying emission coefficients. Many published transport sectoremission coefficients implicitly assume vehicle stock and characteristics similar to those found inindustrialized regions. While these conditions are obviously not found in most developing countries, localdata are generally unavailable. Furthermore, the data are often U.S.-based, reflecting substantiallydifferent vehicle stock and emission control regulations than found in many other regions.

Some of the available data on vehicle emissions are shown in Table 4.6, below. These dataillustrate the wide range of emission factors pertaining to different models and vintages of vehicles. Thetable illustrates the dramatic reductions in emissions of several pollutants (CO, HC, and TSP) achieved innewer U.S. vehicles, due to emission reduction technologies (e.g. catalytic converters) resulting from U.S.regulations.

4.8.3 Fuel extraction activities

Another area where emission and impact factors may be extremely site specific is in energyextraction, specifically mining of coal, oil shales, and uranium ore, and drilling for petroleum products andnatural gas. In coal mining, the principal emission to the atmosphere is methane. The amount of methanereleased per tonne of coal mined varies widely from coal seam to coal seam, depending on geology andwhether the coal is surface-mined95 or underground mined. Within the latter category, methane emissionsvary according to mining procedures (USEPA, 1990a) such as how much coal is left in place and what typeof ventilation is used. Other emissions from coal mines, such as acid mine drainage, also depend largelyon mining practices and site-specific geology, topography and hydrology. For oil and gas drilling largevariations in emissions are likely to arise due to differences in the state and maintenance of equipment , thedegree to which natural gas is captured and routed to pipelines instead of being vented or flared, and thegeneral care and vigilance with which the operation is run.

95Surface-mined coal is removed by first scraping off the rock and soil (called the "overburden) that lies above the geologicalstrata where the coal occurs (called the "coal seam"). Once the overburden, typically several to tens of meters thick, isremoved, the coal itself is scraped away, usually with the aid of very large heavy equipment. Underground mining, while alsousually machine aided, involves digging a shaft into the earth to the coal seam removing the coal, and bringing the mined coalback up to the surface through the shaft.


Table 4.6:SAMPLING OF EMISSION FACTORS FOR MOTOR VEHICLES

Type Source Unit CO2 CO HC CH4 NOx SOx TSP Pb N20AUTOMOBILES Gasoline

Senegal - Mix of India and Netherlands, IPPC/uncontrolled g/kg 2660 263 38.5 1.38 32.4 0.39 0.50 0.243 0.04Car-India Bose et al. 1992 g/kg (a) 354 53 23.1 0.78 0.243Jeep-India Bose et al. 1992 g/kg (a) 367 54 24.0 0.78 0.243Car - U.S. - uncontrolled IPCC 1991 g/kg 323 50.3 1.38 17.0 0.04Car - U.S. - 3 way watalyst IPCC 1991 g/kg 50 10.5 0.32 7.9 0.30Car-Netherlands: 1985 fleet, 1.4-2 l engine EEC 1988 g/kg (b) 171 24 41.7 1.01U.S. midsize, 27 mpg, uncontrolled OECD 1986 g/kg 2470 380 30 48.5 1.24 0.321965 U.S. em. std., emissions in 90, leaded USEPA 1985 g/kg 2160 582 75 169.0 0.96 0.0271975 U.S. em. std., emissions in 90, unleaded USEPA 1985 g/kg 2680 251 33 13.5 0.16 0.0041985 U.S. em. std., emissions in 90, unleaded USEPA 1985 g/kg 2920 97 12 8.3 0.27 0.0041990 U.S. em. std., emissions in 90, unleaded USEPA 1985 g/kg 3050 13 7 4.6 0.30 0.004

DieselSenegal - Mix of India and Netherlands, IPPC/uncontrolled g/kg 3140 12 8 0.06 11 7.13 4.98 0.08Jeep - diesel Bose et al. 1992 g/kg (a) 3 1 5.1 7.13 0.17Car - U.S. - advanced control IPCC 1991 g/kg 3188 11 3.6 0.12 8.0 0.08Car - U.S. - uncontrolled IPCC 1991 g/kg 3188 6 3.1 0.06 6.1 0.08Car-Netherlands: 1985 fleet, 1.4-2 l engine EEC 1988 g/kg (b) 22 15 15.9 9.78

MOTORCYCLE/OTHER Gasoline

2 wheeler - India Bose et al. 1992 g/kg (a) 519 324 n/a 0.82 0.254Motorcycle - U.S. - uncontrolled IPCC 1991 g/kg 3172 405 111.0 5.60 3.2 0.04

BUSES Diesel

India Bose et al. 1992 g/kg (a) 22 8 40.9 7.13 0.17LIGHT DUTY VEHICLES (LDV) Gasoline

LDV - U.S. - uncontrolled IPCC 1991 g/kg 3172 303 58.1 1.18 17.9 0.04LDV - U.S. - advanced 3 way catalyst IPCC 1991 g/kg 3172 58 9.4 0.50 8.4 0.30

TRUCKS/HEAVY DUTY VEHICLES (HDV) Diesel

HDV - U.S. - uncontrolled IPCC 1991 g/kg 3188 22 7.6 0.26 42.9 0.08HDV - U.S. - advanced control IPCC 1991 g/kg 3188 22 4.1 0.19 16.3 0.08

BOATS Gasoline

Outboard engine USEPA 1985 g/kg 2240 534 178 1.1 1.04 Diesel

Best guess 3120 11 2.7 0.23 35 7.82 2.07 0.08Boats IPCC, 1991 g/kg 3188 21 4.9 0.23 67.5 0.08Commercial Steamships EPA, 1985 g/kg 3140 1 0.4 3.3 7.82 2.07

Blank entries indicate no data are reported for that pollutant. (a) Converted from g/l using a density of .74 kg/l for gasoline and .87kg/l for diesel.(b) Converted from g/km, assuming 25 mpg or 9.4l/100 km.

The health and safety impacts of both mining and petroleum/natural gas extraction also varywidely with the particular operation. Underground coal mines tend to have more accidents and injuries pertonne of coal extracted than do surface mines, but among underground mines, the number and severity ofincidents varies according to the types and quality of equipment used, safety regulations and protocols, theparticular mining methods employed, and the geological nature of the coal and surrounding bedrock.Injuries and accidents in oil and gas fields are also, primarily, a function of equipment maintenance and thedegree to which good safety practices are followed.


4.9 Major sources and types of emission factors data

EDB includes emission factors from more than 50 different documents and databases. Fullcitations for these sources are given in the References section of EDB (an annotated version of thisreference list is provided as Annex 2 to this document), and many of them have been used in preparing thismanual. There are several major, general sources of emission factors. These are the emission factorscollected by the U.S. Environmental Protection Agency (USEPA), the Intergovernmental Panel on ClimateChange (IPCC), the CORINAIR database assembled by researchers in Europe, and the World HealthOrganization’s Rapid Assessment of Sources of Air, Water, and Land Pollution (WHO, 1982).

4.9.1 The USEPA's Emission Factor Databases

The USEPA maintains a database of emission factors, as well as active research programs in (toname a few) measuring emissions from different types of devices, estimating emissions of differentcompounds from different sources, and refining methods for testing emissions.

The best-known set of documents on emission factors published by the USEPA are referred to asthe "AP-42" series, titled Compilation of Air Pollutant Emission Factors. Volume I of this series covers"stationary" sources of air pollution--from utility boilers to home wood stoves. Volume II covers mobilesources--from motorcycles to ships to heavy equipment. AP-42 covers what are known as the "criteria"air pollutants, principally CO, NOx,, SOx, hydrocarbons, and particulates. Emissions of lead areoccasionally included as well, as are emissions of methane, nitrous oxide, and carbon dioxide. AP-42 wasoriginally published in the early 1970's, and different parts of it have been updated many times, includingan update to some sections in early 1995. Many of the stationary-source emission factors in AP-42 arealso contained in a database called EFACTOR which is referenced by process type (e.g. "industrial coalboilers") and by Source Classification Code. In addition to emissions from fuel consumption, both AP-42and EFACTOR contain factors describing emissions from other processes, including those in the industrialand agricultural sectors.

Other tools available from the USEPA include a databases of VOC (volatile organic carbon)profiles, which give the estimated breakdown of total VOC emissions among specific species of organicmolecules (e.g. methane, ethane, benzene, etc.) for emissions from many sources, and a database of PM(particulate matter) profiles, breaking down emissions of particulate matter into several size ranges96. Allof these databases are available from the EPA on a CD-ROM disk (a format similar to the "compact disks"used for sound recording, but containing data instead of music) called "AIR CHIEF" (USEPA, 1992).These databases and other materials are also available through the USEPA's "CHIEF" electronic bulletinboard system. Researchers whose computers are equipped with modems can call up this bulletin boardand obtain a wide variety of information on environmental topics, as well as the most recent updates ofemission-related EPA documents, computer models, and databases.

The EPA also is very active in the field of global warming, and has published a compendium offactors to be used in the estimation of greenhouse gas emissions (USEPA 1990b). This compendiumdraws heavily on emission factors from AP-42.

96Particulate matter emissions of different sizes cause different human health impacts. For instance, while particulates oflarger than a certain size are filtered out in our noses and throats, smaller particles can make their way to our lungs, where theycan cause or exacerbate respiratory problems.


4.9.2 Emission factors for Greenhouse Gasses from the IPCC

In February of 1991, the OECD (Organization for Economic Co-operation and Development,based in Paris) organized an "Experts Meeting" for the IPCC in order to reach consensus on emissionfactors and other procedures for data collection and the estimation of greenhouse gas emissions fromanthropogenic (human) activities. As a part of this effort, which is documented in the report Estimation ofGreenhouse Gas Emissions and Sinks, (OECD 1991), a compilation of emission factors for energy-usingequipment was produced, covering the residential, commercial, industrial, and utility sectors, and providingfactors for emissions of CO2, CO, NOx, CH4, N2O, and non-methane VOCs. Emission factors foragricultural activities and land-use changes are also provided in this report. Much of the information inthis report has been updated and re-formatted in the IPCC/OECD compendium Greenhouse Gas InventoryWorkbook: IPCC Draft Guidelines for National Greenhouse Gas Inventories (IPCC/OECD 1993). Forthe energy sector, this set of emission factors draws heavily on the USEPA documents referenced above.

4.9.3 CORINAIR

CORINAIR is a subset of a program called CORINE, which is designed to spur and coordinate thecollection of environmental information among the countries of Europe. The program is under theauspices of the Commission of European Community (CEC). CORINE stands loosely for "Coordination -- Information -- Environment". CORINAIR is the portion of the program dealing with atmosphericemissions. Part of the CORINAIR project has involved the compilation of an emission factors handbookcovering a range of economic activities, including stationary sources, agricultural sources, roadtransportation, and "nature" (biogenic emissions). The emissions included in the emission factor databaseare SOx, NOx, and VOCs, although the database may be extended to cover other pollutants (Fontelle et al,1990). The database is called EEC - DG XI - CORINAIR Emission Factors, and is available from theCEC (Veldt and Bakkum, 1988). The emission factors in this compendium are drawn from collaboratingresearchers and institutions throughout Western Europe, and may include some data from other sources(such as the USEPA) as well.

4.9.4 The World Health Organization

Another source of information used frequently in compiling EDB has been the World HealthOrganization’s Rapid Assessment of Sources of Air, Water, and Land Pollution (WHO, 1982).This compendium includes some factors for emissions of pollutants to air and water for various energysector technologies, but was also used as a source for information on direct health and safety impacts ofenergy technologies.

Summary: potential uses and misuses of emission factors

Emission and impact factors are essential when you are preparing an emissions inventory orprojecting energy-related emissions or impacts. Databases such as EDB make it possible to come up withnumerical estimates without an extensive, difficult, and often expensive effort to collect environmental data.Emissions estimates are produced by applying emission factors to economic or energy data that are usuallymore easily obtained than basic environmental data. Emissions estimates can be used as inputs to models


that simulate the effects of emissions on parameters such as human health, local air quality, acidprecipitation, or climate change.

Some of the different methods used to sample emissions were discussed earlier in this Section;some are better than others for particular applications, and some, with the passage of time, may come to beseen as error-prone. In general, the higher the number of tests performed, or samples taken, to estimate anemission factor, the higher will be the confidence in the final figure established. Samples should ideally betaken over a range of operating conditions, and emissions data for a range of different individualinstallations or devices should be collected. As an example, if you wanted to derive a set of emissionfactors for the fleet of "tricycles" (a small motorcycle equipped with a sidecar for passengers and/or goods--they are in wide use in the Philippines, Thailand, and other Asian nations) in your country, you wouldwant to take several readings of the emissions for each test vehicle, but also to be sure to test vehicles ofdifferent ages, from different manufacturers, and in different locales, trying to get a mix of vehiclesrepresentative of the country-wide fleet. A similar procedure would be optimal if you were trying toestimate emissions from wood stoves, which vary greatly in their design and operating characteristics fromplace to place and even, sometimes, household to household.

As in all types of numerical estimates, however, it is important to bear in mind the limitations thatexist to using published estimates of emission or impact factors. In particular, it may be useful to askyourself the following questions:

• Does this particular emission (or impact) factor (or set of factors) correspond well to the particulardevice, technology, or situation under consideration?

• What is the underlying uncertainty in the emission factor, and how does it correspond to the uncertaintyin the data (such as energy use data) to which I want to apply it?

• Do I know enough about the source of emissions I wish to model (such as the types of wood stovesused, and how they are operated) to make reasonable assignments of emission factors from theliterature? If not, how can I find out more?

• Did I adequately document my assumptions and sources so that future research can build upon mywork?

• Are my efforts in finding just the right emission factor for a particular device or set of devices worththe effort, that is, will the use of factor A versus factor B make a big difference in my final result?(This helps determine how much work to devote to particular aspects of your study, keeping in mindthe overall goal).

It is important, and perhaps reassuring, to think of your efforts at using emission and impactfactors in energy/environment analysis as steps in an ongoing process that will involve future updates andimprovements. As such it is important to do the best job you can and to realize that part of the job will beto identify gaps in the data and areas in need of further research. Your efforts and future research will helpto reduce the uncertainties surrounding the relationships between energy choices and the environment, andultimately lead to better-informed decisions on energy policy.

5. Developing Loadings Inventories and Projections for the EnergySector

Developing Loadings Inventories and Projections for the Energy Sector 95

5.1 Introduction

In previous sections of this manual we have tried to give an overview of the basic approaches inenergy/environment planning, review the major environmental issues that are of concern to planners andconvey a sense of what emission factors are and where they come from. In this section our focus is morespecific. The goal here is to provide a general step-by-step guide to preparing pollutant and impactloadings inventories and projections. After a brief description of LEAP and EDB, we present the overallsteps that are involved in such an analysis, followed by a concrete example--for a hypothetical “CountryX”--showing how these steps can be implemented. This section ends with a description of a LEAP andEDB application in Costa Rica.

5.1.1 Why Prepare Pollutant Loadings Inventories?

Inventories of pollutant loadings--and of estimated direct impacts--from energy sector activitieshave a number of uses in the fields of planning, policy evaluation, and environmental regulation. Aninventory of pollutants is an estimate of current pollutant loadings and other impacts, presented by type ofpollutant or impact and often by location of emissions and/or by economic sector. Pollutant “loadings” arereleases of gaseous, liquid, or solid wastes to the environment. Some of the specific uses of inventories orloading are as follows:

• Estimation of future loadings: Planners use “base year” estimates of pollutant loadings as an input toprojections of future pollutant loadings. These estimates, in turn, serve as indicators of futureenvironmental quality, or inputs to other models.

• Estimation of the ambient local concentrations of key air pollutants: Inventories of key air pollutants

(such as NOx, SOx, CO, particulate matter, hydrocarbons) in, for example, an urban airshed are usedto estimate the concentrations of these pollutants--and the chemical species that are formed byatmospheric processes--in the local air. These concentration estimates, in turn, are used to determinehealth risks. Box 5.1 describes an example of such an application in Mexico City. Similar estimatesof the ambient concentrations of toxic air pollutants also start from emissions inventories, as doestimates of the concentrations of water pollutants in receiving rivers, lakes, and other bodies of water.

• Estimation of the transport of air and water pollutants: Inventories of pollutants, including toxic and

other air and water pollutants, can be used as inputs to models that estimate the patterns with whichthese pollutants are dispersed in the local environment.

• Input to transport models of regional pollutants: Precursors to acid precipitation, for example (see

Section 2) are emitted locally but may have their major environmental impacts hundreds or thousandsof kilometers away. Estimates of local loadings of these pollutants are used as inputs to the modelsthat track acid precipitation.

• Input to global greenhouse gas models and national greenhouse gas abatement studies: Inventories

of greenhouse gas (GHG) emissions can be used as inputs to estimates of emissions of these gases on aglobal level. These in turn provide inputs to predictions of future concentrations of GHGs, which areused to evaluate the environmental consequences of GHG concentrations. Preparation of a GHGinventory is required of all nations that have signed the Framework convention on Climate Change. It


is also the necessary first step in preparing national plans to abate future emissions of greenhousegases.

A number of different analysis tools can--and should--be used to perform the types of studies listedabove. LEAP is just one of these tools, but its characteristics--including its ability to link to theEnvironmental Database and the way that it can be used to easily model future scenarios--make itparticularly useful in many energy planning activities. LEAP and EDB were used for the “Country X” andCosta Rica studies described below.

Box 5.1: Using an Emissions Inventory for Mexico City

The capital city of Mexico, Mexico City, is home to over 19 million people. Mexico city lies in ahigh-altitude valley surrounded by mountains, two of which are over 5000 meters tall. This topography,coupled with the light winds in the area, means that air pollutants tend to remain in the area onceemitted. The many and varied activities of the population, including petroleum refining, electricitygeneration, numerous industries and service establishments, and a vast fleet of transport vehicles--allcontribute emissions to the airshed, resulting in frequent episodes of poor air quality.

To help understand and alleviate this problem, Mexican authorities have, with assistance fromUNEP and others, established a system of pollution monitoring stations, and have also established aninventory of air pollutant emissions, as shown in Table 5.1, below. This inventory has helped to indicatewhat sectors and processes are major sources of emissions, and has helped local authorities to designand implement contingency programs to respond to severe pollution episodes, as well as medium-rangeplans for halting the growth of pollution. Contingency programs in Mexico City include reducing theactivity of highly polluting industries, restricting vehicle traffic. More permanent changes include closingthe local PEMEX refinery, converting power plants to run on natural gas, lowering the sulfur content offuel oil burned locally, retrofitting vehicles to burn natural gas, limiting automobile CO emissions, andrestricting commuter traffic. A longer-term initiative is to replace old, high-emissions industries with non-polluting activities.

Source: World Health Organization and United Nations Environment Programme (1994), “Air Pollution inthe World’s Megacities”. Environment, Volume 36, #2, pages 25 to 27.


Table 5.1:Emissions Inventory for the Metropolitan Area of Mexico City

SulfurDioxide

Partic.Matter

CarbonMonoxide

Oxides ofNitrogen

Non-MethaneHydrocarbons

Sector (Units: Thousand tonnes per year)Energy PEMEX* 14.7 1.1 52.6 3.2 31.7 Power Plants** 58.2 3.5 0.5 6.6 0.1Industry Industry 65.7 10.2 15.8 15.8 39.9 Services 22.0 2.4 0.4 0.4 0.1Transport Private Cars 3.5 4.4 1,328.1 41.9 141.0 Taxis 0.8 1.0 301.1 9.5 31.9 Combis and minibuses 0.8 1.0 404.4 10.0 42.7 Urban buses 5.2 0.2 6.2 8.0 2.4 Suburban buses 13.0 0.6 12.6 18.2 5.3 Gasoline trucks 0.9 1.1 779.5 16.9 67.8 Diesel trucks 20.0 0.9 16.5 26.1 7.2 Other 0.2 0.1 5.0 2.7 1.6Environmental Degradation Erosion 0.0 419.4 0.0 0.0 0.0 Forest fires, etc. 0.1 4.2 27.3 0.9 199.7TOTAL*** 205.7 450.6 2950.6 177.3 572.1

*Closed in 1991**Switched to natural gas in 1991***Sums of columns may not add to total, due to rounding.Source: WHO and UNEP, 1994.

5.2 LEAP and EDB

Together, LEAP and the Environmental Database (EDB) comprise a computerized modelingsystem designed to explore alternative energy futures, along with their principal environmental impacts,using the analytical steps outlined below. As a flexible, model-building tool, model relationships and detailcan be tailored to the dynamics of particular energy situations and to the data constraints of individualapplications. A brief description of LEAP is included in Box 5.2, below.


5.3 Step-by-Step Guide to Performing Energy and Environmental Analysis

Box 5.2: The Structure Of LEAP

LEAP is structured as a family of easy-to-use microcomputer programs, the LEAP energy planning systemis suitable for performing energy assessments in developing or industrialized countries, for multi-country regions, orfor local planning exercises. It consists of three groups of main programs: Energy Scenario, Aggregation, and theEnvironment (and an optional add-on group for making macroeconomic projections). The Energy Scenarioprograms address the main components of an integrated energy analysis: demand analysis, energy conversion,and resource assessment. This group consists of three programs for building scenarios (Demand,Transformation, Biomass/Land Use), a program for reporting environmental emissions and one for comparingand evaluating scenario costs and impacts. The planner uses the scenario building programs to develop currentenergy balances, projections of supply and demand trends, and scenarios representing the effects of energypolicies, plans and actions. The Environmental and Evaluation programs compute the physical impacts of movingfrom one scenario to another, the economic costs and benefits, and the environmental emissions. TheAggregation program assemble area level (district, nation, region) energy accounts and projections into multi-arearesults. The Environmental Data Base, EDB, provides a comprehensive summary of the information linking energyproduction, conversion and consumption activities to air and water emissions, and other environmental and healthconsequences, that can be linked to energy scenarios to provide measures of the environmental consequences ofalternative futures. Note that the diagram below does not include the newest LEAP program element, namely thefuel chain program, which allows the side-by-side evaluation of the resource, cost, and environmental impacts ofdifferent ways of providing the same energy services.

E n e r g yS c e n a r i o s A g g r e g a t i o n E n v i r o n m e n ta l

D a t a b a s e

B i o m a s s

E v a l u a t i o n

E n v i r o n m e n t

T r a n s f o r m at io n

D e m a n d

The Demand program provides a framework for disaggregated, end-use analysis of final energyrequirements. Data are assembled in a hierarchical format, based on four levels: Sectors, Subsectors, End-uses,and Devices. Depending on data availability and analytical choices, the user can define an appropriate structureand select from among several options for making future projections (such as growth rates, fixed targets, elasticityrelationships, etc.). The Transformation program simulates the energy sector conversion processes that turnprimary resources, such as hydropower and crude oil, into final fuels, such as electricity and kerosene. Theprogram compares the primary resources and fuel imports and exports required to provide the final fuelconsumption calculated by the Demand program. Major transformation processes are handled by specializedmodules — e.g., electricity production, ethanol plant, oil refining, oil and gas production, coal mining, charcoalkilns, biogas production, etc. — while others may be user defined. The Biomass Resource/Land Use programexamines the impact of biomass requirements and land-use changes on the biomass resource base. Biomassprojections are based on the inventory of wood stocks and yields, crop yields, crop residue availability, and dungproduction, at various levels of spatial detail. The Environment program links the physical processes created inthe scenario programs to EDB, to track the emissions loadings and impacts of alternative scenarios. TheEvaluation analysis includes the impacts of technology and project costs, inflation, discount rates, and foreignexchange components of each option, and can account for either market or shadow prices, as well asenvironmental externality costs, if included.


Figure 5.1 below, and the text that follows, present the general steps in perform energy andenvironment planning studies (as summarized in Box 1.1), and indicates where LEAP and EDB can beused to assist the planning process. Once again though the steps below specifically

Figure 5.1: FLOW DIAGRAM FOR PREPARING ENVIRONMENTAL LOADINGS PROJECTIONS

IN ENERGY-ENVIRONMENT ANALYSIS

POSSIBLE TOOLS: STEP 1:Determine Planning Goals

STEP 2:Investigate Energy Use Patterns,Assemble Available Energy Data

STEP 3:Prepare Baseline Scenarios

STEP 4:Prepare Alternative Scenarios

STEP 5:Collect Environmental Data and

Estimate Loadings

STEP 6:Analyze Policy Options and Implications

LEAP :Demand,

Transformation,and

BiomassPrograms

Cost CurvesSurveys

Interviews

LEAP EvaluationProgram,

MacroeconomicAnalysis,

Financial Analysis

EDB, LEAPEnvironment

Program


5.3.1 Determine Planning Goals

The first step in assembling a LEAP/EDB energy/environment planning analysis, or similaranalyses using tool or framework, for that matter, is to determine what information you, as a planner, wishto obtain from the planning exercise. While this may seem obvious, a clear statement of planning goalscan help shape your study, including the form of the model you will create and what type of data you willcollect, and as such, allow you to spend your time on activities that are directly oriented toward providingthe information you need most. For example, if what is needed is an all-sector overview of differentenergy futures for the country, the best approach might be to develop a model structure that allows thetesting of broad policy instruments, and to gather energy and environmental data that spans all of thesectors of the economy, but does not go into great detail in any one sector. Conversely, if what is needed isvery specific information on the potential outcome of applying policies to a particular sector, such as thetransport sector, you will want to create an energy database that allows you to test very specific policies(such as taxes on particular fuels, subsidies to electric or alcohol-fueled vehicles, or import policiesdesigned to increase the fuel efficiency of the vehicle fleet), for which you would seek detailed datadescribing the sector you wish to concentrate on, and less-detailed data for other sectors.

On the environmental side, your consideration of planning goals should include, for example a listof the pollutants (and environmental impacts resulting from pollutants) that you want to learn about.Urban air pollutants, acid gases, or greenhouse gases, for example--each with impacts as described inSection 2 of this study--might be a focus of your study. You may be looking to create an inventory ofemissions in order to apply techniques, like those described in Section 6, that are used to estimate theultimate environmental impacts of the emissions in the inventory.

For “Country X”, the assumed planning goals are to prepare a model structure that will serve asthe basis for an inventory of present and future emissions of air pollutants, particularly greenhouse gases,and can also be used to explore different options to reduce the country’s emissions of GHGs and otherpollutants.

5.3.2 Investigate Energy Use Patterns and Assemble Available Energy and Environmental Data

One way to begin this task is to draw a crude diagram or table showing what energy end-uses areimportant in your country or region (or those which end-uses you wish to include in your modeling effort),which energy resources are being used or are available to supply those end-uses, and what categories ofenvironmental loadings or impacts result from the operation of the energy system you are looking at. Thischart or table will then provide a guide to gathering the data that you will need to inform your study.Information on the patterns of energy flows may be available from existing national or state energybalances, from earlier narrative descriptions of the energy system you are modeling, from existing energysurveys, and from your fellow planners and engineers who are familiar with the way that the energy systemworks.

The types of energy and environmental data that you will be trying to locate may include (with thelevel of detail depending on the focus of your study):

• Energy End-Uses, including data that conveniently describe how much of a given fuel is used to meetan end use, and the distribution of different energy-using devices in your energy system (for example,what fraction of rural household stoves use wood, and what fraction kerosene?).


• “Activities”, or quantities such as population, the number of households, income, changingtechnologies, and other parameters that are likely to affect the demand for energy in the future.

• Energy Supplies--including primary resources such as coal in the ground, fuel imports, exports, andlosses, and important fuel production and conversion processes such as coal mining, oil and gasextraction, and petroleum refining, and charcoal manufacture.

• Land use and biomass stocks and yields

• Costs of energy technologies, fuels, energy resources, and environmental resources (e.g. emissionsvalues). Technology costs will include both the non-fuel costs of operating a given type ofequipment, and the capital costs of that equipment.. Resource costs can include costs of importedand domestic fuels, as well as the export prices for fuels sold abroad.

• Qualitative, and especially quantitative data on the environmental impacts of energy production anduse.

• Existing forecasts of key parameters that will affect future energy use in your country, state, orregion. These forecasts could include estimates of future economic and industrial activity, futuretrends in transport, expansion plans for electric and petroleum utilities, and forecasts of populationand household size

Sources for the types of data listed above include National or State data compendia and otherpublications; international (for example, United Nations, World Bank, or IEA/OECD) statistics; articles,reports, and books from the academic sector; and, in some cases, statistics from the commercial andindustrial sector. Where data are sparse, interviews with people familiar with activities in particularsectors can help to provide at least approximate information to fill in the gaps.

Some of the key characteristics of the demography, economy and energy system in Country X arepresented in Box 5.3, below.


5.3.3 Prepare Reference Case Projections

The preparation of reference case projections, using the data you collected in step B, above as a"base year" starting point, involves several intermediate tasks. The first of these is to design a structurefor the model of your energy system. Here, you will want to bear in mind the modeling objectives you aretrying to achieve (as defined in step A), as these objectives will help you decide, for example, what level ofdetail to use in your LEAP Demand data set for each sector, or which are the important energy supplytechnologies that could change in the future, and thus should be included in your Transformation data set97.

Once your LEAP data structures are mapped out, the next task is to load the data you collectedduring step B into LEAP, and assess the need for additional information. Quite often you may find, whileentering data into LEAP, that the data you have collected lack sufficient detail for some sectors or end-uses, or for certain energy supply technologies or resources. In addition, you may find that some of thedata you have collected are inconsistent. In either case, you may need to return to step B to seek additionaldata or to clarify existing information.

Having loaded the information you have available into LEAP, the next task is to run the Demandand Transformation modules of LEAP, review the results, and go back and "de-bug" your data structuresas required. Here it is very important to look carefully at your results. Is the total energy consumptionfor the base year about what you expected? Are there unexpected increases or decreases in the use ofcertain fuels or in energy use in certain sectors? Are the energy unit what you expect? If you noteproblems, you will need to return to your LEAP Demand and Transformation models and correct them.Happily, as LEAP results often take only seconds to produce, it is relatively easy and quick to check theresults of your data corrections. Here it should be emphasized that the estimates of environmental loadingsare based on the LEAP estimates of fuel use and production, so it is important to make sure that your

97Again, the reader is urged to consult the LEAP User Guide for more detail on how data are entered into LEAP and howLEAP models are built.

Box 5.3: Key Characteristics of Hypothetical Country “X” • A middle-income developing economy of 40 million people. (~$600 GDP per capita);• GDP is expected to grow at 3.5% per year through, while population is expected to grow at 2.5% per

year;• As of 1990, 30% of the country’s 8 million households reside in urban areas, a fraction which is

expected to rise to 45% by 2030. Due to decline numbers of persons per household from 5 toaround 4, the number of households increases at 3.0% per year, faster than population;

• Low but growing per-capita energy use (7.5 GJ total end-use energy per capita in 1990);• A relatively diversified economy, with significant commercial and manufacturing activity, and energy-

intensive, basic materials industries (iron and steel, cement, chemicals, and paper and pulp);• A mostly oil-based energy system, with considerable use of traditional fuels, particularly in rural

areas;• A current stock of electricity generation facilities that includes hydroelectric (25% of 1990

generation), oil-fired (25%), and coal-fired (50%) plants;• Expected increasing reliance on indigenous coal to fuel a growing electricity demand;• Access to imported gas and some indigenous renewable resources;• Irrigated agriculture, which accounts for about 10% of base year electricity demand;• Currently modest but rapidly growing demand for personal transportation services; and,• An ongoing program of rural electrification, with 95 percent of the households in the country

expected to have electricity service by 2030, compared with 65 percent in 1990.


energy results look reasonable before continuing on to calculation of pollutant loadings and other directenvironmental impacts.

For Country X, the set of reference or “base case” scenario assumptions used is described in Box5.4.

Box 5.4: Reference Case Scenario Assumptions for Country X

• Population grows at 2.5 %/year through 2030. Due to an ongoing reduction in the size of households, thenumber of households grows at 3.0%/year. The share of households in urban areas increases from 30% in1990 to 45% in 2030;

• National GDP grows at 3.5%/yr. through 2030, with faster growth in the commercial or services sectorcompared to the industrial sector;

• Rural electrification increases the number of electrified rural households from 65% to 95% from 1990 to 2030;• Rising standards of living increase the saturation of electric end-uses (refrigeration, air conditioning,

television, etc.), the level of lighting usage (up at 1.0% per year), and the rate of switching from traditional tomodern cooking fuels. With the exception of slower improvements in traditional cook stove efficiency(0.3%/year), the energy efficiency of household devices improves at about 0.5% per year, reflecting the naturalreplacement of older with newer more efficient appliances;

• Energy demand in the commercial, agricultural, and most industrial sectors grows with sectoral value added(GDP). The baseline energy intensity (energy use per unit value added) decreases by 0.5%/year;

• Personal transport services, indicated by passenger-kilometers traveled per capita, increases at 2.5%/yr. until2010 and 2.0%/yr. beyond that. There is a gradual shift from public transportation to private vehicles. Privatepassenger vehicles are assumed to have an average natural increase in energy efficiency of 0.75%/year, whilethe natural increase in efficiency of buses, trains, and planes is 0.5%/year;

• Freight transport (tonne-km per capita) grows at 2.0%/year. Freight transport undergoes a slow shift fromsmaller trucks to larger trucks and from road and water-borne freight to air and rail freight. Road freight stillmaintains a dominant 78.5% share of freight transport by 2030, only a modest reduction from its 1990 level of83%;

• About two-thirds of new electric capacity is coal-fired, the remaining one-third is oil-fired. Existing facilitiesare retired at the end of their planned lifetimes, with the exception of hydroelectric facilities which aremaintained;

• Domestic coal production capacity is expected to increase almost four-fold over 1990 levels by 2030;• No new oil refining capacity is added;• The real price of crude oil and refined petroleum products increase modestly, averaging 0.8%/year (real)

through 2030. (Based on UNEP, 1994b); and,• Indigenous renewable resources (wind, solar, and biomass) remain untapped, except for continued use of

traditional woodfuels and existing hydroelectric capacity.

5.3.4 Prepare and Run Alternative Scenarios

At this point you have mapped out and run your "base case" LEAP projection. The next step is todefine and run some energy scenarios that address some of the planning goals that you defined in step A.LEAP scenarios are defined by changing one or more of the values in your base case data set that affectfuture energy demand and/or fuel supply. You might wish to explore, for example, what will happen if thepopulation of your country or region grows more slowly than anticipated, or more quickly. You would dothis by changing the population or household growth rates built into your base-case data set. You mightalso ask what the implications would be of increased electricity use in the residential sector. This could bemodeled by increasing the fraction of households using electricity for certain end-uses, and decreasing thefraction of homes using other fuels. In any event, the goal in this step is to estimate the effects on energy


demand and supply of different "futures" that your country or region might face, or of policies that mightbe undertaken to shape a different energy future.

For Country X, a GHG mitigation scenario was fashioned incorporating the following GHG-reduction measures:

• Residential lighting efficiency improvements. A program would encourage the replacement ofincandescent with much more efficient compact fluorescent light bulbs in both urban and ruralhouseholds.

• Residential refrigerator efficiency improvement. A standards or import tariff program wouldimprove the efficiency of new refrigerators on the market.

• Improved industrial and commercial lighting and motor drive efficiency. This could beachieved through standards, incentive programs, tariff and import policies, or other policyinstruments.

• Switching from coal and oil to natural gas for industrial sector process heat applications.Natural gas furnaces and boilers produce less CO2 per fuel consumed, and are often moreefficient as well, requiring less fuel consumption.

• Improving vehicle efficiency for automobiles, light and heavy trucks, and buses. This could beachieved through standards, incentive programs, tariff and import policies, or other policyinstruments.

• Replacement of new coal-fired electric plants with more efficient natural gas combined-cyclefacilities that have lower CO2 emissions per unit electricity output. Natural gas would beimported via pipeline from a neighboring country.

• Windfarms for electric generation. Most added capacity will occur between 2010 and 2030, bywhich time the technologies for power generation from wind are expected to be mature andcost-competitive in most applications.

• New nuclear power stations. These would be the first nuclear units in the country.• Solar photovoltaic electric generation.

Note that these measures also help meet many other planning goals, including reduction of fuelimports, more intensive utilization of local renewable resources, reducing local pollutant emissions bymoving to “cleaner” and renewable fuels, and generating local expertise in the installation and use ofrenewable energy systems. Each measure has its associated costs, characteristic energy resource needs perunit of energy services provided, and environmental impacts.

For Country X, these measures were assumed to be “penetrate” the energy system, that is, beimplemented, at different rates, beginning in 1994 or thereafter. For instance, for agricultural pumpsets, itwas assumed that approximately one-quarter of all units would be replaced in 20 years, or an overallpenetration rate of 1.25% per year. Since improved pumpsets could reduce electricity consumption by40%, the overall energy intensity for agricultural pumpsets declines at 0.5% per year. As the result ofsimilar sets of assumptions for efficiency improvement, energy intensities for other targeted end-usesdecline at rates of 0.25% per year (commercial/industrial motors) to almost over 2% per year (residentiallighting, first 20 years) relative to baseline scenario levels. For industrial fuel switching, it was assumedthat about 1% per year of coal and oil use applications could be switched to natural gas, up to 20% by2010 and 40% by 2030. For the power sector, it was assumed that combined cycle gas facilities couldreplace about 40% of planned coal additions, leading to 1000 MW of gas-fired capacity by 2010 and 3600MW by 2030. The wind power potential was limited to 200 MW by 2010 and 1500 MW, orapproximately 9% of total installed capacity, in 2030.


5.3.5 Collect environmental data and estimate loadings

Estimates of environmental loadings calculated with LEAP and EDB are only as good as theenergy and environmental data on which they are based. In an ideal world, you would be able to use yourenergy data, as entered in LEAP, with emissions factors calculated based on the measured performance ofequipment, appliances and vehicles in your own area. While this is, in practice, not possible--fewcountries at present have undertaken extensive measurements of emission factors--you should make aneffort to collect what local emission factors and direct impact data are available for your area. This mayinvolve contacting local researchers in the environmental field and asking for their test results, or locatingstudies that have investigated the environmental characteristics of energy technologies similar to those usedin your country. When these types of data have been assembled, they can be entered into EDB. It is agood idea to check existing EDB emissions coefficients for similar devices (if available) as you enter yourlocal data, as such cross-checking may turn up anomalies or errors in the emission factor data that couldprove troublesome later on.

Once you have entered any available local emission factor data into EDB, you are ready to "link"EDB to your LEAP data set. This is done from within the Demand and Transformation modules of LEAPby indicating, for each appropriate device in the Demand program, and for each different type of process inthe Transformation program (for example, for each different type of electricity generation facility), fromwhich EDB "source" category LEAP should take emissions coefficients. Here some words of warning arein order. First, your emissions/impacts inventory will be only be as complete as the EDB categories towhich you have linked your LEAP data set. It is perhaps obvious that if you link only a small fraction ofthe Demand devices in your data set with EDB sources, your reports in the Environmental Evaluationmodule will only reflect a fraction of the true emissions or impacts in your country. Note here that someLEAP devices may not need to be linked. End-use consumption of electricity, for example, generally hasfew directly associated emissions or impacts (the impacts of producing electricity are, of course, notnegligible, and are typically captured by EDB links through the LEAP Transformation module), and thuselectricity-using devices are usually not linked to EDB source categories. Section 4 of this documentprovides additional guidance and background on the choice of emission factors.

Less obvious, but equally important, if the EDB source category to which a particular LEAPdevice or process is linked does not provide complete coverage of the emissions or impacts you areinterested in, your inventory will be incomplete. For example, you may, in the process of making links,discover an EDB category that appears to be a good match to a LEAP Demand device, but when you checkthe emission factors available for that category (as you browse through EDB) you may find that theparticular EDB source category you have linked to provides only one or two emission factors, and does notcover one or more key pollutants that you wish to include in your inventory. It is necessary to bothperform links to all of the LEAP devices and processes that are likely to produce emissions or impacts, andto make sure that your links are to EDB source categories that provide appropriate coverage.

For Country X, we created links to EDB using a selection of mostly generic EDB sourcecategories, but we were careful to select source categories that provided good coverage of the greenhousegases, that is, source categories with emission factors for most or all of the important greenhouse gases thatwe wanted to study.

Once links between EDB and your LEAP Demand and Transformation data sets have beenprepared, the final step is to run the Environmental Evaluation module to calculate the loadings and directhealth and safety impacts that are projected to result from your base case and alternative LEAP scenarios.


As with the LEAP energy results, you should review the output of the Environmental module to make surethat there have been no major errors in data entry or in linking. Use the reporting features of the programto focus on results by sector, subsector, end-use, fuel, and transformation process. Are there areas inwhich you expect emissions or impacts of certain types, but none are reported? If so, you may havemissed making some links, or some key EDB coefficients may be missing. On the other hand, if certainresults look too high, and you have satisfied yourself that the energy data in LEAP are not in error, it maybe that one of the user entered or Core EDB coefficients are wrong98.

Key results of our Country X analysis, for both the “Baseline” and “Mitigation” scenarios, areshown in Table 5.2, below.

Table 5.2:Selected Physical Indicators for Country X Scenarios

Baseline Scenario Mitigation Scenario1990 2010 2030 2010 2030

Final Consumption (Million GJ) 296.9 548.5 1064.8 505.5 898.7 Petroleum Products 151.7 318.4 667.1 279.7 524.6 Electricity 65.2 137.4 281.7 125.7 235.5

Primary Energy (Million GJ) 469.5 926.2 1851.0 810.9 1429.5 Coal 168.5 430.4 936.7 284.4 429.3 Natural Gas 0.0 0.0 0.0 64.7 223.8 Petroleum Products 216.8 410.9 810.3 366.7 663.0

CO2 Emissions (Million Tonnes) 26.8 57.7 124.1 47.9 86.5CO Emissions (Thousand Tonnes) 477.2 819.6 1,623.0 740.2 1,305.2CH4 Emissions (Thousand Tonnes) 84.1 214.5 419.8 143.5 219.2NOx Emissions (Thousand Tonnes) 95.9 180.6 371.3 159.7 287.9

The steps above provide a general guide to energy and environmental analysis using LEAP andEDB. One thing to keep in mind in all applications of LEAP and EDB is that LEAP is designed so that itis easy to update data sets, recalculate results, check the new results, and update the data again. Thismeans that you can easily start out using what data you have available, and build on it later, and alsoemphasizes that importance of thinking critically about the data you gather and the results you produce tomake sure that they are both as accurate as you can make them, given information and other resourceconstraints, and also that they meet your policy evaluation requirements. In sub-section 5.3, below, wepresent a concrete example of how the steps listed above have been implemented in producing a specificenergy/environment study of reference and alternative scenarios of energy production and use in CostaRica. For your reference, Box 5.5 provides a summary of the way that calculations are carried out inLEAP and EDB for an analysis like the Country X and Costa Rica examples presented here.

98Another possibility is that there is an error in the fuel composition data entered in LEAP. For some types of emissionfactors, emissions depend in part on the fraction of a particular element or substance present in the fuel. Sulfur oxideemissions, for example, will often depend on the fraction of sulfur in the fuel. If this fraction has been entered incorrectly, alllinks to EDB coefficients that reference this fraction will be in error.


Box 5.5: The Flow of Calculations in the LEAP/EDB System

In the LEAP/EDB system, the flow of calculations in proceeding from initial assumptions (enteredor selected by the user) to final estimates of pollutant loadings and other direct environmental impactscan be summarized as follows:

Basic Equations:

Energy Consuming Activity x Device Share x Energy Intensity = Energy Use by Device

Energy Use (device) x Loading Factor (effect, device) = Loadings

Where:

Energy Consuming Activity = An activity or energy service for which fuel is consumed, for example, avehicle-kilometer traveled

Device = Any process or technology that produces, consumes, or loses energy (such as electrictransmission and distribution).

Device Share = The fraction of an activity served by a particular device, such as the fraction of vehiclekilometers traveled by diesel buses

Energy Intensity = The amount of fuel used to provide a unit of the desired activity or energy service--liters of diesel per kilometer traveled, for example.

Energy Use = Measured in tonnes (or other physical units) of fuel produced, consumed, or lost by adevice.


Box 5.5 (continued):

In the above, the model of energy production and use (including energy consuming activities,device shares, and energy intensities) is constructed in LEAP, and "links" are made from within LEAP tomatch devices to sets of loading factors (for each "source") in EDB. Once these links are complete,loadings are calculated from within the Environment Program of LEAP (see Box 5.2, above).

At this point, several key features of the LEAP/EDB of approach should be understood in orderto appreciate both the limitations and the capabilities of the software:

1. The calculation structure of LEAP/EDB assumes a linear relationship holds between energy use(consumption, production, or losses) and environmental loadings.

2. The mitigation measures that can change loading factors can be grouped into two categories:changing technologies and operating practices (includes adding pollution control technologies toexisting equipment, or changing the composition of the fuel consumed). These can be handled inLEAP by changing, over time, to greater use of devices with different sets of loading factors (e.g. byshifting the composition of your future vehicle fleet to include a higher proportion of cars equippedwith NOx-reducing catalytic converters) or by changing fuels, say, to lower sulfur coals, to reduce SOx

emissions.

3. LEAP and EDB do not, at present, provide any modeling of environmental impacts beyond directloadings of pollutants and selected direct health and safety impacts. Loadings reports from theEnvironmental Evaluation Program of LEAP can, however, be used as input files for softwareprograms outside of the LEAP system that are designed to estimate impacts.

4. EDB does not, at present, provide information on non-quantifiable impacts of energy production anduse (such as the aesthetic impacts of a power plant on local vistas).

5. Through the Cost-Benefit Evaluation Program of LEAP, it is possible to attach monetizedenvironmental costs to pollution loadings estimates, and thus bring environmental costs directly into

the overall cost-benefit analysis of energy scenarios99

6. As LEAP and EDB do not provide coverage of most non-energy activities, you should keep in mindthat an evaluation of the energy sector provides only part of the picture, and the most importantenvironmental problems may lie elsewhere. LEAP does, however (through the Biomass program),provide the capability to study the impacts of land use changes--whether energy or non-energy-related, on the biomass resource base.

5.4 A Case-Study Application of LEAP and EDB: Costa Rica

Using much the same approach as outlined above, LEAP and EDB was used as a software tools ina forward-looking energy/environment planning study focusing on Costa Rica. Key modeling choices,input data assumptions, and results are described in the summary below. For another example of theapplication of LEAP and EDB, please see the study of the United States contained in America's EnergyChoices Investing in a Strong Economy and a Clean Environment (Union of Concerned Scientists et al,1991). In the summary of the Costa Rica study that follows we have indicated how the study techniquesused correspond to the suggested Steps in Preparing Environmental Loadings Projections In Energy-Environment Analysis as listed in Figure 5.1. 99Note that while this procedure for incorporating environmental costs into a cost-benefit analysis, while seeminglystraightforward, requires a good deal of thought in the choice of the monetary values to be attached to loadings of differenttypes. While attempts have been made to make the choice of these values as objective as possible, this choice remainsprimarily a subjective one.


5.4.1 Costa Rica100

In 1991 and 1992, SEI-B and the Latin American Energy Organization (OLADE) collaborated ona preliminary application of LEAP/EDB in Costa Rica. Some of these data used for this analysis wereavailable at OLADE, as part of the Sistema de Informacion Economica Energetica (SIEE), and additionaldocuments were collected by SEI-B and OLADE personnel during visits with the Costa Rican host agencyfor the project, the Dirección Sectorial de Energía (DSE) in San Jose. In the remainder of this section, webriefly introduce the context for energy and environment planning in Costa Rica, outline the differentenergy scenarios tested, and report on key results -- future energy use, emissions of pollutants to theenvironment, and estimated costs -- of these scenarios using the methodology outlined above. For fulldetails of this study, the reader is urged to see the complete report on the Application, available both inEnglish and Spanish. (Von Hippel and Granda, 1992)

The Energy and Resource Situation in Costa Rica (Step 2 in Figure 5.1)

Costa Rica covers 51,000 square kilometers (LANL, 1987). Half of the population of 2.72million lives in urban areas (SIEE; OLADE, 1991). The overall population density is 53 people per km2,one of the lowest in Central America. The rate of population growth is just over two percent per year(World Bank, 1990), also one of the lowest in the Central America region. The population in urban areasis increasing somewhat faster than the population as a whole.

Table 5.3 shows the breakdown of 1988 energy use in Costa Rica by sector and by fuel. Biomassfuels ("Firewood" and "Other") provide 42 percent of the final energy consumed in Costa Rica, withpetroleum fuels providing 41 percent and electricity 15 percent. All crude oil and refined petroleum fuelsare currently imported. Electricity production and capacity is mostly hydroelectric. The residential sectoris the largest consumer of energy (44 percent), of which nearly three-quarters is firewood. The transportsector contributes 32 percent of total fuel demand, and consumes nearly 80 percent of all of the refinedpetroleum products used in the country. The industrial sector accounts for 23 percent of consumption.

Overall, per capita energy consumption has remained relatively stable between 1984 and 1989, at4.2 to 4.4 bpe101/person, down from its highest level of 4.6 bpe/person in the late 1970's. The energy-economic energy intensity, in bpe/$1000 US (1980) has decreased slightly from 3.2 in 1985 to 3.0 in 1987to 1989. Since 1982, transport fuel consumption has risen steadily at an average of 8.0 percent per year(SIEE; OLADE, 1991).

100 Portions of the following text were excerpted from Von Hippel and Granda, 1992.101 Barrels of petroleum equivalent (BEP in Spanish).


Table 5.3:Energy Consumption in Costa Rica (1988)in Barrels of Oil Equivalent (BOE or BEP)

SectorPetroleumProducts

Electricity Firewood Other Total Percentof Total

Transportation 3940 4 0 0 3944 32%Industrial 946 525 223 1067 2775 23%Residential 134 1291 3907 0 5393 44%Commercial/Public

0 57 0 0 57 0.5%

TOTAL 5020 1877 4130 1067 12169

Percent of Total 41% 15% 34% 9% 100%

Since the 1960s, there has been no fossil fuel production in Costa Rica. Costa Rica has extensivehydropower resources that are as yet unexploited, and geothermal development is underway in the westernpart of the country at Miravalles. The supply of biomass fuels for residential needs in Costa Rica iscurrently adequate, though future firewood supplies could be limited somewhat by ongoing deforestation,which is driven by expansion of agriculture, and by changes in the way coffee plantations are cropped.Solar energy is an attractive option for Costa Rica, but frequent cloud cover limits the applicability oftechnologies requiring direct solar radiation. Wind energy resources in Costa Rica, surveyed in the early1980's, could contribute a small portion of Costa Rica's electricity needs, particularly in isolated areas.

The primary challenge for the Costa Rican energy and resource sectors in the coming years will beto provide the fuels and energy services required for economic development given 1) limited availability offunds for capital investment 2) potential environmental and resource constraints on expansion of energysupply such as changing land-use patterns, continued deforestation, limits on hydropower development,and, conceivably, climate change agreements102, and 3) problems obtaining the necessary foreign exchangefunds to pay for imported fuels. The preliminary application of LEAP/EDB was designed to test some ofthe options available for meeting Costa Rica's energy needs (Steps 1, 3, and 4 in Figure 5.1).

Five exploratory scenarios included:

• A Base Case scenario that assumes future energy consumption is determined primarily by thelevel of economic development of the country and by the growth rate of the population. The dependencyof energy demand on economic development was modeled, quite simply, as a direct relationship betweendemand and GDP or population, and in some cases (such as transportation), both. Growth in this caseis based on the supposition that the economic trends of the 1980s will continue.

• A Continuidad scenario that departs modestly from the Base Case scenario by assuming astronger economic growth rate, increasing in the intensity of useful energy consumption (heat energydelivered in the form of steam, for instance) in the industrial sector, and maintaining constant energyintensities in other sectors.

102 Of course, depending on its final form, Costa Rica could conceivably benefit from an international climate changeagreement.


• A Transformación scenario that reflects support for development from outside Latin Americaand allows Costa Rica to invest in continued social and technological development that, in turn, reducesthe energy intensity of many energy activities, especially in the industrial and transport sectors.

• A MIPE/MEDIO scenario that closely matches the results of a mid-range scenario fromDSE's own MIPE planning model (DSE, 1990). Major modifications of the Base Case values toachieve this match included higher projections of GDP growth, higher electricity use in the servicessector, higher population/household growth, higher electricity use for cooking in residences, an increasein the demand for transport services, and a shift toward more use of diesel fuel.

• A MIPE/MEDIO + Efficiency improvements scenario that is based on the MIPE/MEDIOscenario described above, but includes the improvements in energy efficiency in each of the majorsectors. These improvements are based on readily available technologies.

Future capital investments in energy supply facilities -- electricity generation plants, for example --were assumed in the Base Case to follow the National Generation Expansion Plan (ICE, 1991), and similarplans for the petroleum refining sector. A large (3-fold) increase in electric generation capacity is foreseenunder this Plan, with about 75 percent of the added capacity to be in the form of hydroelectric andgeothermal plants, and the remainder fossil-fueled.

In the Base Case scenario, wood consumption remains relatively steady, while demand for mostfossil fuels and electricity increase. Figure 5.2 shows the overall fuel demand for each of the five casesover time. Demand in the MIPE/MEDIO case is far higher than the other cases, with the largest percentagedifferences by sector appearing in the services, residential, and industrial cases. It is interesting to notethat just by adding a few simple efficiency measures, overall year-2010 fuel demand in the MIPE/MEDIO+ Efficiency case is reduced almost 20 percent relative to the MIPE/MEDIO case.

Figure 5.2:Total End-Use Costa Rica Energy Consumption, Five Scenarios

Using methods described in Section 4 of this document, "devices" or sources of environmentalemissions, for which emissions data are available in the Environmental Data Base, were matched with fuel-using devices (and energy transformation equipment such as power plants) called for in the scenarios

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described above (part of Step 5 in Figure 5.1). Using these data, estimates of current and future emissionsof several common air pollutants were obtained. Results for four of these pollutants -- carbon dioxide(CO2), carbon monoxide (CO), hydrocarbons, and nitrogen oxides (NOx), are presented in Figure 5.3. TheMIPE/MEDIO scenario produces the highest level of emissions of each of these pollutants by the year2000, while the "Transformación" and MIPE/MEDIO + Efficiency Scenarios are the most effective,overall, in reducing emissions, principally because both involve increases in energy efficiency and,typically, newer, less polluting equipment.

Figure 5.3:Selected Air Emissions Results for Five Scenario Tested

NET CO2 EMISSIONS: FIVESCENARIOS

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In addition to the energy demand, energy supply, and environmental emissions elements describedabove, the Costa Rica study also examined, using the methodology contained in the LEAP BiomassModule, two different scenarios of changing land uses. These scenarios integrated the effects of demandfor biomass fuels, pressures on land due to increasing urban and rural populations (and the need for foodby those populations) and other ongoing shifts in land use. The Base Case scenario assumed that theaverage deforestation rates encountered over the last 20 years would continue, while a second Biomassmodule scenario assumed that trends in (reduced) deforestation noted over the last few years would holdinstead. In the Base Case, forest stocks in Costa Rica were estimated to be substantially depleted by 2010,while land use changes when the more recent trends in deforestation were assumed were much moremodest, with small increases in the land devoted to annual crops, pastures, and settlements being offset byan approximately 10 percent decline in forest area.

Differences in costs and benefits between two scenarios, the MIPE/MEDIO case and theMIPE/MEDIO + Efficiency Case, were examined (part of Step 6 in Figure 5.1). The categories of costsand benefits considered for each case were the costs of energy end-use equipment (stoves, automobiles,


etc.), the costs of energy transforming equipment and facilities (such as power plants), the costs ofdomestic, imported and exported fuels and resources (especially oil products), and the costs ofenvironmental externalities. These cost categories correspond to, respectively, the "Demand","Transformation", "Resource" and Environment" elements in Figure 5.4 below.

Figure 5.4:Cumulative Costs (Positive Values) and Benefits (Negative Values) of Shifting

from the Reference Scenario to the Alternative Scenario(MIPE/MEDIO + Efficiency)

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TRANSFORMATION

DEMAND

When efficiency measures were added to the MIPE/MEDIO Case, electricity demand was reducedsufficiently that several of the planned generating plants could be avoided. The combination of theMIPE/MEDIO case with the Base Case generation expansion plan form the "Reference" case shown inFigure 5.4 below, and the combination of the MIPE/MEDIO + Efficiency Case with reduced constructionof power plants form the "Alternative" case. As Figure 5.4 shows, the benefits of increasing energyefficiency far outweigh the costs, particularly when environmental costs are factored in (using monetaryexternality values described later in this paper). The total net cumulative discounted value (using a realdiscount rate of approximately 4 percent), in 2010, of the transformation, resource, and environmentalbenefits of shifting to the higher-efficiency scenario are estimated as $640 million, $415 million, and $950million, respectively ($1990). These benefits are "purchased" at a cost of $334 million, which is the extracost for improved-efficiency demand devices. Summing over the four types of costs yields a net benefit ofabout $1.67 billion. If environmental costs are left out of the analysis, there is still a net cumulativebenefit of about $720 million in moving to the Alternative scenario. Significantly, there are alsoconsiderable foreign exchange benefits to Costa Rica in adopting energy efficiency measures, principallybecause the costs of oil imports are avoided. It should be noted that this type of analysis, where both costsand benefits are ignored after a specific cut-off date (here 2010), tends to reduce the net benefits accruingbecause of investments in efficient demand devices, as it ignores those benefits of demand-side investmentsthat occur after the end of the analysis period. For example, an efficient industrial boiler purchased in2008 will still be saving fuel resources in the year 2111, but these resource savings are not counted in thetotal benefits calculation.

The excellent availability of data in Costa Rica, coupled with the existence of an able and veryhelpful in-country collaborating agency (DSE), made the Case Study described above a very fruitful one.The case study demonstrated the usefulness of the LEAP/EDB methodology for integrated


energy/environment planning, and, in a preliminary way, pointed up policy opportunities that Costa Ricamight pursue to meld the goals of development, cost containment, and increasing energy efficiency.

While Costa Rica faces many of the same problems as other countries in the region, includingexcessive debt, reliance on imported petroleum and petroleum products, and deforestation, the country isblessed with a low population density, fairly abundant resources, and a sophisticated planning bureaucracywell-versed in appropriate planning techniques.

Scenario analysis shows that relatively robust growth in energy demand in Costa Rica can beaccomplished without exceeding available resources (as in the MIPE/MEDIO scenario), although paymentsfor major new energy facilities may be problematic. While the scenarios explored in this report do not, ofcourse, begin to explore the various options open to Costa Rica, they suggest that the country has thepossibility to provide a very positive development model for the countries of the region. To some extent,however, Costa Rica, due to its small internal demand for major consumer goods, must remain a prisonerof international technology choices. The prime example of this is in the transport sector, where use ofautomobiles designed and produced in larger nations generates much of the pollution and foreign exchangeproblems in the country.

As part of the project, a Working Group was formed, drawing its members from six differentCosta Rican government organization involved in energy planning. The task of this working group was tohelp evaluate the usefulness of the LEAP/EDB methodology in a Costa Rican context while they gainedfamiliarity with the approach. One quite rewarding aspect of the Working Group, was that it provided anapparently unique opportunity for mid-level planners in the ministries represented to sit down to 1) evaluatea single tool together, and 2) discuss the status and approach of planning in their organizations. Theinteresting general discussion about planning that arose pointed up one of the strengths of LEAP; since it isa tool that crosses the traditional boundaries of planning ministries, it can serve as a catalyst for greatercoordination and cooperation between the different organizations that have the responsibility for guidingenergy/environment policy in a country.

5.4.2 Environmental Analysis and Valuation in the Costa Rica Study

The environmental analysis and valuation methods employed in both studies were rather similar.First, emission factors were developed using Environmental Data Base. For the United States study theCore data of EDB were augmented with available emissions data that represent both existing and emerginglocal technologies and operational practices.

The two greatest difficulties in a quantitative environmental approach are the integration of factorsthat are impossible or difficult to measure or generalize (such as ecological damage, soil degradation, andaesthetic impacts), and the comparison across seemingly incommensurate impacts (such as balancinghuman health, ecological, and economic costs and benefits). In addition, there can be considerableuncertainties in identifying and generalizing relationships between emission and other environmental insults(e.g. the amount of land flooded by construction and operation of a hydroelectric station) and the actualdamages that result. In particular, for energy sources whose use can have extensive land use impacts --resources such as woodfuel, hydroelectric power, and geothermal energy -- the overwhelming influence ofsite-specific factors (the local climate and ecology, land use patterns) render the use of generalized modelsnearly impossible, if not downright misleading. The danger of biasing energy choices towards thoseoptions whose environmental impacts are most difficult to assess or quantify -- “confusing the countablewith the things that count” -- must be avoided.


At the same time, increasing quantification, even monetization, of environmental externalities isproceeding at a rapid pace. In the U.S., 29 states have acted to incorporate environmental externality costsin electric sector planning.103 Internalizing environmental costs has been termed "the wave of the future"internationally as well, with 85 pollution taxes already in place by 1989 in OECD countries (Ottinger,1991, p. 190). So-called market-based initiatives, are rapidly spreading worldwide. Other options forincorporating environmental externalities -- including solely qualitative assessment,ranking/weighting/matrix schemes, and strict emission target approaches -- are also possible.

The Costa Rica study used the set of values for air pollutants emissions adopted by in states ofMassachusetts and Nevada, and shown in Table 5.4 below. This valuation was based on previous work byTellus Institute, using a "regulators revealed preferences" approach that is gaining increasing use in theU.S.104 This approach uses the costs of existing and proposed environmental regulations as a proxy for thevalue society implicitly or explicitly places on environmental impacts, and assumes that regulators havemade a reasonable assessment of the regulation's costs and benefits to society. For example, the SO2 costrepresents scrubbing technology required by regulation; the TSP cost represents baghouse technology; andthe CO costs represent the use of oxygenated fuels.

Table 5.4:Air Pollutant Externality Values

Pollutant SO2 NOx CO TSP VOC CO2 (asC)

CH4 N2O

Value(1990$/tonne)

$1700 $7500 $1000 $4600 $6100 $90 $250 $4600

In computing the air pollutant emissions from energy sector activities, the Costa Rica study useddifferent emission factors for its correspondingly different (relative to the US) mix of energy-using and -transforming technologies, but the air pollutant externality values used were the same as noted above.These values were not, however, used for resource selection, but only to produce indicative comparisonswith the direct market costs of the scenarios considered. While, ideally, the values (and methods used toderive them) would be reassessed given the Costa Rican environmental situation, legislation, and priorities,the application of the U.S.-based values does give an idea of what some of the environmental costs mightbe, if emission regulations and control cost options were similar to those currently prevailing in the UnitedStates.

103 Of these, 19 states have issued orders or passed legislation requiring utilities to include these costs in planning or newcapacity bidding processes.104 For a review of this and other approaches see UCS et al., 1992, pp.37-39; Bernow, Biewald, and Marron, 1991; Chernickand Caverhill, 1991; Pearce and Markandya, 1989; and, R. Ottinger, et al., 1990.

Extending the Analysis from Emissions to Damage 117

6. Extending the Analysis from Emissions to Damage

6.1 Introduction

Once an LEAP/EDB analysis is complete, the typical result is a listing of pollutant emissionsand/or specific direct impacts per year. This type of information is often referred to as a loadings oremission inventory, which can be a desirable end point of an analysis. Often, however, you may wish to gobeyond such an inventory to estimate the ultimate environmental damages associated with a particularenergy activities.

Over the past two decades, environmental agencies and researchers have devoted considerableeffort to developing models that have improved our ability to predict environmental damage to humans,crops, materials, and ecosystems. Damage assessment can be either a relatively simple or exceedinglydifficult undertaking, depending on the complexity and uncertainty of the problem at hand. For example,assessing the damages from greenhouse gas emissions presents an enormous scientific challenge, involvingthe use of sophisticated computer models and innovative scientific research methods. Other impacts, suchas the impacts of air pollution on agricultural crops, are better understood and simpler to model.

Due the inherent difficulties and complexities of damage assessment, we have limited the coverageof EDB to loadings and to direct impacts on health and safety, i.e. those that occur at the site of energy useor production, rather than the indirect impacts that occur off-site and later in time, due to a variety ofpossible pathways between loadings and damages. The many possible and often uncertain linkagesbetween loadings and damages generally defy simple linear relationships. In other words, “damage factors”akin to the emission factors in EDB would not be appropriate. At the same time, more sophisticated air,water, and soil models require considerable additional expertise and judgment in their application and areoften site-specific; given that LEAP/EDB users are largely energy analysts rather than environmentalanalysts, we have not, as yet, included such models in the LEAP/EDB framework. The detailed extent ofdata requirements and many factors influencing the choice of specific impact models for any situationrenders full damage assessment a difficult, if not impossible, proposition for LEAP/EDB or any other toolof general applicability.

Some of the descriptions of pollutant impact models provided below will help to give you a feel forthe large amount of information that can be required to estimate final environmental damages of energysector activities. Air pollution impact models, for example, require data on the daily or monthlydistribution of emissions by spatial location, weather conditions at the time of the emissions, regionaltopography, the location of receptors (including people, crops, and sensitive ecosystems), and the acute andchronic response of these receptors to pollutant concentrations. These data and relationships can be highlysite-specific, and it can be difficult to attribute damages to the energy sector, which can be but one of manysources of environmental stress.

In this section, we thus go beyond the scope of the LEAP/EDB framework, and provide somebackground on available techniques and resources for estimating the eventual consequences of current andprojected environmental loadings. We begin by reviewing the steps in damage assessment, stopping shortof the ethically and methodologically challenging area of damage valuation.105 We then describe steps

105 For more discussion on methods for damage valuation, see the related SEI-B report Incorporating Environmental Concernsin Energy Decisions: A Guide for Energy Planners (Hill, Lazarus, Bernow, and Biewald, 1994).


involved in modeling emission-impact pathways for a few typical energy-related environmental concerns.We provide some examples of the types of models used for simulating the fate and transport of pollutantsand their impacts on human and natural systems. We conclude with a brief listing and description of keyresources for environmental modeling and damage assessment.

6.2 Steps of Analysis from Emission to Impacts

Figure 6.1 depicts the major steps in impact assessment for energy activities. The first two steps,characterizing energy activities and estimating loadings, can be done with LEAP/EDB or other similar toolsand techniques. The third and fourth steps, modeling the fate and transport of pollutants and establishingdose-response relationships are the key elements of damage assessment, and the focus of this chapter:

• Transport and fate of pollutants. This step is appropriate for air, water, and soil emissions whereimpacts can occur downwind or downstream from the source of pollution. The objective is to predictambient concentrations of pollutants, and the accumulation of toxic substances, as well as the exposureof populations and ecosystems to the pollutants. This step often requires the use of sophisticated anddata-intensive spatial and temporal atmospheric chemistry and dispersion models, such as, in the caseof global warming, complex global circulation models.

• Exposure-response (or “dose-response”) relationships. For example, what effect will exposures ofsay 5 µg/m3-year of sulfur dioxide have on human health, crop viability, or forest health? These typesof relationships are most commonly determined by laboratory, epidemiological, and field ecologicalresearch studies. Relatively well-defined dose-response relationships exist for some interactions (forexample, SOx concentration and respiratory illness, ozone concentration and crop damage), while manyremain poorly understood (such as climate change impacts on ecosystems and human activities). Thisstep yields actual damage estimates: deaths, health impacts, ecosystem losses, crop and materialdamages, diminished aesthetics, etc.

Additional, more direct damage pathways do not generally require modeling analyses, and areindicated by the dotted line in Figure 6.1. These impacts include population and community displacement,visual impairment, audible noise pollution, land use and degradation, loss of habitat and biodiversity.These impacts are often associated with the construction of major energy facilities such as high-voltagetransmission lines or surface coal mines, but can also be associated with their continued operation (audiblenoise from transmission lines or land degradation from surface mining, for example). They also tend to beamong the most obvious and controversy-provoking environmental concerns created by large energyfacilities. For example, many large proposed hydroelectric dams, such as the Three Gorges Dam on theYangtze River in China, the Sardar Sardovar Dam in India, and proposed dams on the Bio-Bio River inChile, have aroused local and international concern because of displaced communities, loss of wild andriparian habitat, and inundation of sites of natural beauty.


1) Characterize EnergyProject or Scenario

2) Estimate Loadings

3) Model Transport and Fateof Emissions

4) Establish Exposure-Response Relationships

PhysicalDamages

deaths, health impacts, crop losses,forest damage, etc.

pollutant exposures to populations,ecosystems, crops, etc.

technology characteristics, fuel use, losses, etc.

air, water, and soil emissionssolid and hazardous wastes

direct resource use/degradation (soilloss, habitat destruction, land use,etc.) and aesthetic losses (audiblenoise,/visual impact, etc.)

Figure 6.1:Steps in Physical Damage Assessment


These types of impacts tend to require site-specific assessments, in contrast to the types ofmodeling efforts described here. Environmental Impact Assessments (EIA), where required, are naturalsources of this type of impact information. In only a few cases, such as for noise, EMF, and land useimpacts of electric transmission as discussed in Box 6.1, can generalized relationships be applied, and eventhen local assessment would be far superior.

6.2.1 Examples Of Emission-To-Impact Pathways For Some Common Pollutants

The following examples illustrate some of the factors you will need to consider in translatingphysical emissions of pollutants from energy-sector activities to estimates of the environmental damage.The four case below are but a few of the many possible pathways between loadings and damages thatmight be relevant in your region of concern.

Box 6.1: The Environmental Impacts of High Voltage Electric Transmission Lines(Based on Knoepfel, Bernow, and Lazarus, 1994)

In many countries, siting high-voltage transmission lines is becoming increasingly difficult. Localresistance to the lines usually involves concern about the perceived impact of both the line itself and theright of way (ROW) through which it runs. Local residents worry that a power transmission line willchange the area's visual aesthetics. They also fear the impacts of the ROW, in terms of possible soilerosion and potential impacts on wetlands and wildlife. Finally, the public's perception of electric andmagnetic fields (EMF) raises further concerns that should be considered. In the U.S., environmental andland use concerns are, together with the technical and economic assessment of system need, the mostimportant criteria applied in transmission line siting and certification throughout the U.S.

The environmental impacts of electric power lines can occur in ecosystems both at the local and at theregional/global level. Typical local effects are related to the impacts on soils, local hydrology, flora andfauna caused by construction processes and management of the right-of-way (ROW)7. Impacts on theaesthetic quality of the landscape are also of a local nature. Regional/global effects arise from airpollutants emitted at the stages of construction, production of materials, additional generation tocompensate electric losses, maintenance and decommissioning.

Knoepfel (1994) has developed a framework for classifying these impacts, as illustrated in the tablebelow, with some illustrative estimates of impacts typical for 345kV lines in the U.S. Such values,however, must be used with caution, because the precise nature of the proposed right of way andsurrounding land use will have an overriding impact.

Table 6.1:Environmental and health impacts of 345 kV AC transmission lines

(per kWh and 1000 km length).

Impact Category Unit of Measurement Rural Lines Urban LinesNatural habitat impingement 0.001*m2 0.0012 0Land depreciation m2*year 0.037 0.001Audible noise impact pers*hrs 0 3.6(potential) Electric field impact pers*hrs 0 0(potential) Magnetic field impact pers*hrs 0 4.9Impact from air emissions $ 0.007 0.007Air emissions impacts assume coal generation and monetary valuation.


Pathway Between Sulfur Oxide Emissions and Lung Disease

Sulfur oxide (SOx) emissions can result from many energy-sector activities, perhaps most notablyfrom the combustion of coal in domestic, commercial, industrial, or utility stoves, furnaces, and boilers.Chronic (long-term) exposure to SOx emissions can lead to or contribute to lung diseases. Table 6.2shows one pathway between emission and impact for SOx and lung disease, and lists some of the additionaldata that you would need to gather in order to estimate impacts based on emissions.

Table 6.2:Evaluation of the Respiratory Impacts of Sulfur Oxide Emissions

Steps in Evaluation Pathway Data Needed For Estimation Of Impact1. Emissions of sulfur oxides by energysector activities

Sources of fuel combustion, fuel characteristics (e.g. sulfurcontent), combustion and emission control technologies used,emission coefficients (LEAP/EDB), and current and projectedenergy-use activities. Modeling may require emissions dataon a daily or monthly basis.

2. Dilution, transport, andtransformation of SOx in theatmosphere

Prevailing average and extreme weather conditions:temperature on the ground and in the lower atmosphere,humidity, wind, precipitation patterns, and local topography.Presence or absence of other chemical species (such as dust,salts) and rates of chemical reactions.

3. Calculation of average and extremeambient concentrations of SOx

Output of steps 1 and 2.

4. Determination of exposure of localpopulations to SOx concentrations.

Overlay of population distribution data, including identificationof sensitive groups (e.g. elderly and asthmatic) and SOx

concentration data (step 3),5. Estimate of number of additional oraggravated cases of lung disease.

Dose-response relationship between ambient exposure anddisease by class of exposed individual. There may bedifferent calculations for additional cases of lung diseasecaused by chronic vs. acute exposure.

Pathway Between Carbon Dioxide Emissions and Economic Damage Due to Sea-Level Rise

Carbon dioxide emissions from combustion of fossil fuels and from changes in land use arebelieved to be the major contributors to global warming. The resulting partial melting of the polar ice capsand glaciers and thermal expansion of the oceans would increase the average level of the oceans, withpotentially devastating effects to many coastal communities. Translating emissions of CO2 to economicimpacts requires analysis of a cause-and-effect pathway like that shown in Table 6.3.


Table 6.3:Evaluation of the Sea-Level-Rise Impacts of Carbon Dioxide Emissions

Steps in Evaluation Pathway Data Needed For Estimation Of Impact1. Emissions of CO2 by global energysector activities, land-use changes, andother anthropogenic sources

Sources of fuel combustion, fuel characteristics (includingcarbon content), combustion and emission controltechnologies used, emission coefficients (LEAP/EDB), andcurrent and projected energy-use activities.

2. Estimated range of possibletemperature rise

Estimates of the fate of CO2 (absorption by ocean water andgrowing biomass), emissions of other important greenhousegases, and various assumptions regarding the global climatesystem, including the radiative balance of the earth, weatherpatterns, cloud cover, and the modulating impact of theoceans upon climate. These data are then used in "GlobalCirculation Models".

3. Calculation of sea level rise resultingfrom a particular temperature increase

Data on the size and reflectivity of ice caps and glaciers,thermal ocean expansion, and feedbacks between risingoceans, temperatures and melting ice caps.

4. Estimate of human and naturalactivities and assets at risk from sealevel rise

Inventory of population, property, and ecosystems at risk fromsea level rise, probably response to rise.

Pathway Between Nitrogen Oxide Emissions and Impacts on Lake Ecosystems throughAcidification

Nitrogen oxide (NOx) emissions from combustion of fuels have been implicated in the formation of"Acid Rain", which can acidify lakes to the detriment of fisheries and aquatic ecosystems. The steps shownin Table 6.4, below, are one route by which the linkage between NOx emissions and lake ecosystem damagecan be traced.

Table 6.4:Evaluation of the Lake Ecosystem Impacts of Nitrogen Oxide Emissions

Steps in Evaluation Pathway Data Needed For Estimation Of Impact1. Estimate of NOx emissions byenergy sector activities

Sources of fuel combustion, fuel characteristics, combustionand emission control technologies used, emission coefficients(LEAP/EDB), and current and projected energy-use activities

2. Analysis of fate and transport ofNOx emissions in the atmosphere

Prevailing weather patterns, including wind regimes,precipitation patterns, and temperatures. Concentrations ofother constituents of the atmosphere, estimates of the ratesand parameters of chemical reactions in the atmosphere

3. Calculation of the extent and timingof acid precipitation in watershed

Size of lake's watershed, amount of precipitation falling andform of precipitation, timing of snow melt, degree to whichareas receives dry precipitation of acidic species

4. Estimate of the degree to which alake and its surrounding soil is acidified

Type of soil around the lake, chemical buffering capacity ofthe lake and watershed soils, extent of run-off, timing of snowmelt, hydraulic properties of the watershed (such as ratio oflake volume to water flow through lake)

5. Estimate of ecosystem damage dueto acidification

Types of organisms in the lake and watershed ecosystems,population sizes and relationships (e.g. food chains), degreeto which other damaging chemicals (including aluminum) aremobilized by acidification, susceptibility of different lake andwatershed organisms to acidic conditions (or mobilized toxins)

6.3 Types of Models and Approaches for Impact Assessment


Once you have completed your inventory of emissions and direct impacts from energy-sectoractivities, and have determined likely pathways leading from emissions to environmental impacts (as in theprevious section), the next task would be to obtain or derive a series of models to estimate the magnitude ofthe damage. Considerations in choosing among these models will include:

• The type of results desired (ambient concentration by location, biological uptake of toxiccontaminants, etc.);

• The availability of required model data;• The technical expertise and computing resources available to specify, calibrate, and run a

model and to interpret model results; and,• The accuracy and precision of results, which will depend on the application of the results (for

example, to inform a policy decision or to assist in regulation and monitoring).

In this section we provide thumbnail sketches of the general types of models that are available tohelp estimate environmental impacts, and present brief descriptions of some of the available models thathave been developed for particular classes of impact assessments. Ranging from simple to very complexcomputational approaches, we discuss the following five types of models below:

• Stock-flow models• Transport/plume/dispersion/deposition models• Atmospheric chemistry models• General circulation/climate models• Dose-response models

6.3.1 Stock-Flow Models

Stock-flow models can provide the simplest approach to estimating pollutant concentration andaccumulation. These models characterize specific volumes or areas -- urban airsheds, lakes, watershed,etc. -- as well-mixed “boxes”, with inflows and outflows of air, water, pollutants and/or other substances.These models are generally most applicable to estimating the concentrations of pollutants in receiving waterbodies, such as lakes and rivers, but they can be also applied to other environmental media where relativelyeven mixing of the pollutant with the “box” can be assumed.

The simplest forms of these models are called "steady-state" models, and are used to estimate theconditions of a system--for example a lake and its tributary watershed--that has reached equilibrium withrespect to the concentration of a pollutant (that is, a lake in which the concentration of a pollutant is nolonger changing). Box 6.2 below provides an simple of a simple “steady-state” stock-flow model forevaluating pollutant concentrations.


Stock-and-Flow or Box models can also be used to estimate the properties of a dynamic system,such as the modeling of changes in the concentration of a pollutant over time. Harte (1985) provides adiscussion of some of the uses of these types of models, including a variety of numerical examples.106

6.3.2 Transport/Plume/Dispersion/Deposition Models

"Transport", "Plume" or "Dispersion" models can be used to estimate the concentrations of air orwater pollutants at a distance from the points where the pollutant is emitted. The results of these modelscan be used to determine compliance with air or water quality standards or used to infer human healtheffects or other environmental impacts, through the use of exposure-response models (see below).

These models, generally, use a combination of mathematical relationships107, and require detaileddata on wind (or water flow) patterns, terrain, and precipitation, to approximate the dispersion of pollutantsover time, in a receiving airshed or body of water. These models range in complexity from those simpleenough to be calculated on a programmable hand calculator or personal computer to those requiring main-

106Harte, J. (1985). See for example Sections A and D of Chapter II.107These include "Gaussian", "Lagrangian" and "Eulerian" algorithms used to calculate, in a probabalistic manner, howconcentrations of pollutants will vary in time and space as they spread out from their sources

BOX 6.2:A Simple Stock-Flow Model for Lake Pollution

Situation: A geothermal power plant releases brine (very salty water) into a nearby mountain lake. On anaverage day, the plant releases brine containing 6000 tonnes of salt (Sin). You can assume that the lake is well-mixed, that the water coming into the lake (except for that released by the plant) is fresh water, and that waterleaves the lake via an outflow river at a rate of 10,000 m3/day (Fw). You want to calculate the averageconcentration of salt in the lake water, and to evaluate whether this salinity level will harm the lake’s plants andorganisms.

Solution: Because we have assumed that the lake is well-mixed, he concentration of salt in the water exiting thelake should be the same as the average concentration is the whole lake itself. This is the notion of “steady-state”conditions; initial conditions would be “dynamic” as the concentration in the unpolluted lake rises. Further, atsteady-state, the amount of salt entering the lake from the power plant must be the same as the amount of waterexiting the lake in the outflowing river. This means that we can determine the concentration of salt in the lake bycalculating the concentration (C) in the lake outflow: C = Sin/ Fw, or 6000 tonnes/day divided by 10,000 m3/day.The time units (days) cancel, and we are left with a resulting concentration of 0.06 tonnes per m3, or 60 grams ofsalt per liter. To put this value into perspective, the salinity of the ocean is (on average) about 35 grams per liter.The salt burden provided by the power plant would thus exceed a marine environment, with likely serious damageto the existing freshwater ecosystem.

MOUNTAIN LAKE

Salt inflowSin = 6000t/day

Water outflowFw = 10,000 m3/day


frame or supercomputers. The types of models available can be grouped into several overlappingcategories of applicability:

• Short-range models used for receptor areas within about 50 kilometers of a source of airpollution;

• Long-range or regional models designed, as their name implies, to estimate the concentrationsor deposition of pollutants over a wider area and over a longer time-frame;

• Point-source models, which estimate pollutant concentrations due to emissions from a majoremitter, such as a power plant or a large industrial facility; and,

• Area-source models, which look at emissions from a combination of point sources, often toosmall, such as automobiles or residential stoves and furnaces, to be given a specific location,and thus considered “area sources”.

Economopolous (1993)108 presents a pair models for use in rapid evaluation of the impacts of air

pollution, along with all of the equations, definitions of site-specific data requirements and non-site-specifictechnical data needed to run them. The first model is a "Short Term Critical Impact Analysis" tooldesigned to evaluate whether concentrations of a pollutant from a point source exceed critical levels forshort-term (e.g. one-hour) exposure. The second model is for "Long Term (Seasonal or Annual) ImpactAnalysis", and is used, as the name implies, to estimate the average values of pollutant concentrations, thistime from point or area sources, in a given receptor area.

Another excellent source for those seeking information on the availability and applicability of avariety of air quality models is the United States Environmental Protection Agency document Guideline onAir Quality Models109. This extensive document provides a review of the models available for specifictypes of applications, discussions of the general requirements, considerations, data needs, and uncertaintiesin air quality modeling. It also provides lists describing both a) the air quality models preferred by theEPA, and b) alternative air quality models to the preferred lists. These lists are included as Appendix C tothis manual--along with the table of contents from the EPA document--to illustrate the large number ofavailable models and the important issues to consider in their application.110

One use of long-range transport and deposition models is in the modeling of acid precipitation.The goal of these models is to estimate the location and strength of acid precipitation (acidity in rain andsnow, as well as from dry deposition) caused by air pollutant emissions. A major source of the acidpollutant emissions (for example, the United Kingdom) may be hundreds of kilometers away from theregion of deposition and ultimate impact (such as Scandinavia). Several models have been developed tohelp estimate the impacts of acid gas emissions (primarily SOx and NOx).

108Economopolus (1993).109United States Environmental Protection Agency (USEPA), Guideline on Air Quality Models. USEPA Office of Air andRadiation, Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina, USA. Report number EPA-450/2-78-027R, originally published July 1986. Portions of the report were revised with "Supplement A" (July 1987) and"Supplement B" (February, 1993). This report, and many others touching on air quality emissions inventories, emissionscontrols, and emission modelling, are also available through the USEPA computer bulletin board service, which can be reached(by those with a computer and modem) by dialing (in the United States) 919-541-5742.110As an example, H.P. Baars, K.D. van den Hout, and C. Huygen describe a tool designed for use in evaluating the extent andimpacts of local air pollution in the Netherlands in their paper "Air Pollution Information System Tool for Desk Top AirPollution Management on a Local Scale", published in Environmental Models: Emissions and Consequences, RisøInternational Conference, 22-25 May, 1989, edited by J. Fenhann, H. Larsen, and G.A. Mackenzie. Published by ElsevierScience Publishers, Amsterdam, The Netherlands, 1990.


Two models consider not only the emission, transport, and deposition of acid pollutants, but thesensitivity of local ecosystems and, using postulated dose-response relationships, the impact on affectedareas. These models, CASM111 and RAINS112 were both developed in Europe, at the StockholmEnvironment Institute and the International Institute for Applied Systems Analysis, respectively, but haverecently been extended for other regions including South Asia, where acid precipitation is a growingconcern. They also contain optimization capabilities that enable the user to evaluate a least-cost, least-damage acid rain abatement strategy.

6.3.3 Atmospheric Chemistry Models

Some air pollutants, after they are emitted, can be involved in important chemical changes in theatmosphere. These changes can render a pollutant less or more hazardous to the environment. Many ofthe models discussed above have atmospheric chemistry components, and most atmospheric chemistrymodels will have some pollutant transport elements.

Tropospheric ozone models are a prime example of atmospheric chemistry models. Ozone can be amajor urban air pollutant, associated with photochemical smog, but is not directly emitted from humansources in significant amounts. Instead, it is produced by the atmospheric reaction of nitrogen oxides andvolatile organic compounds in presence of sunlight. Several ozone models are available, but they areparticularly complex and quite consumptive of computing and data resources.113 Nonetheless, someefforts are underway to produce models that are more easily calibrated (tested with data from monitoringstations) and calculated, and thus may be more practical for use in developing-country settings.114

6.3.4 General Circulation/Climate Models

General circulation models (GCMs) are used, in part, to estimate the long-term effect on the earth'sclimate of changes in the atmosphere, including the changes in concentrations of greenhouse gases. Severalsuch models currently running on large mainframe computers at different centers around the world.115

They operate at different levels of spatial aggregation, that is, they break the surface of the earth into"cells" of different sizes -- and the atmosphere into different numbers of "layers" -- for modeling purposes.Some of the many elements of the climate system that need to be modeled include116:

111Stockholm Environment Institute, 1991. An Outline of the Stockholm Environment Insitute’s Coordinated AbatementStrategy Model (CASM). SEI, Stockholm.112See for example Alcamo et al (1987), "Acidification in Europe: A simulation model for Evaluating Control Strategies",Ambio, Vol. 16 number 5, pages 232 - 245.113 See discussion of ozone modeling in Rowe, R. Lang, C. et al. (RCG/Hagler, Bailly, Inc.1993), New York EnvironmentalExternalites Study: Task 2, Externalities Screening and Recommendations, prepared by RCG/Hagler, Bailly, Inc.for the EmpireState Electric Energy Research Corporation, New York.114See for example G.M.Johnson, S.M. Quigley, and J.G. Smith, "Management of Photochemical Smog Using the AirtrakApproach", in 10th International Conference of the Clean Air Society of Australia and New Zealand, Aukland, N.Z., March1990, pp. 209 to 214, and C.L. Blanchard, P.M. Roth, and H.E.Jeffries, "Spatial Mapping of Preferred Strategies for ReducingAmbient Ozone Concentrations Nationwide", Presented at the 86th Annual Meeting and Exhibition of the Air and WasteManagement Association, June 13-18, 1993, Denver, Colorado, USA.115Laboratories running GCMs include UKMO (United Kingdom Meteorological Office), GFDL (Geophysical Fluid DynamicsLaboratory, Princeton, USA), CCC (Canadian Climate Center), MRI (Meteorological Research Institute, Japan), NCAR(National Center for Atmospheric Research, Boulder, Colorado, USA), and GISS (Goddard Institute of Space Studies, NewYork, New York, USA).116Intergovernmental Panel on Climate Change (IPCC, 1990), Scientific Assessment of Climate Change, IPCC WorkingGroup I Report, J.T. Houghton, Chairman. Chapter 3, "Processes and Modelling" authored by U. Cubasch and R. Cess. IPCC


• The atmosphere• The oceans• The cryosphere (ice and snow cover, especially at the poles)• The biosphere (trees, and other vegetation, soil, etc.)• The geosphere (for example, how the land is involved in cycles of evaporation and

precipitation of water)• Different time scales of climate processes• Radiative feedback mechanisms

In general, global circulation models must be run on the fastest supercomputers available, and arethus not practically available for use by most energy planners. Simpler models of specific climateprocesses and elements of the climate system do exist, however. (see IPCC, 1990) For example, theAtmospheric Stabilization Framework (ASF) used by US EPA in its widely distributed report, PolicyOptions for Stabilizing Global Climate, is available in PC form.117 The STUGE (Sea level andTemperature change Under the Greenhouse Effect) model is another simplified PC-based model that can beused to estimate the climatic implications of greenhouse gas emission scenarios at a global level.118

6.3.5 Dose-Response Models

Dose-response models represent a class of tools used to estimate the “response” of an individual,group of individuals, or ecological system to a “dose” of pollution. Different dose-response relationshipsare needed for different response pathways.

In their simplest forms, these models are linear or non-linear relationships in which the impact of apollutant--such as the fraction of a population (of plants, fish, humans, or any other organism that will beaffected (killed, injured, or diseased)--is expressed as a function of the dose of the pollutant to which theorganism is, on average, exposed. The dose may be expressed in micrograms of pollutant absorbed by anorganism per unit body weight (or surface area), a length of time that an individual is exposed to aparticular concentration of a gas in the atmosphere, or (as in electro-magnetic radiation and radioactivematerials) an amount of energy absorbed by the body of an animal or human. Linear dose responserelationships imply that the impacts of a dose of pollutant will increase linearly as the dose is increased.“Threshold” dose response relationships are non-linear: no impact is felt until a pollutant dose reaches athreshold value. Such relationships are intended to represent the hypothesis that organisms can toleratesmall doses with no adverse effects, whereas above a threshold value, negative impacts begin.

More complex dose-response models may take into account the interactions of different types ofplants and animals living together in an ecological community (e.g. the concentration of a pollutant a foodchain), the conversion of a pollutant into a less (or more) dangerous substance through biological (like the

Secretariat, Geneva, Switzerland. See also Chapter 4 from the same volume: "Validation of Climate Models", authored byW.L. Gates, P.R. Rowntree, and Q.-C. Zeng. The IPCC has prepared several publications updating this Assessment (IPCC,1992; IPCC, 1994).117United States Environmental Protection Agency (USEPA, 1990c), Policy Options for Stabilizing Global Climate: Report toCongress (Main Report and Technical Appendices). USEPA Reports #s 21P-2003.1 and 21P-2003.3, USEPA Office ofPolicy, Planning, and Evaluation, Washington, D.C. USA.118Wigley, T., Holt, T., Raper, S. 1991. STUGE, an Interactive Greenhouse Model, Climate Research Unit, University of EastAnglia, Norwich, U.K.


detoxification or toxification of a compound in the body) or physical processes (for example, throughchemical reactions in the atmosphere), or the effect of a release of a point-source pollutant on a populationthat is not homogeneous with respect to exposure and/or susceptibility to the source of the pollutant. Thislast category of relationships might, for example, include evaluating the relationship between emissions of atoxic substance from a power plant, and cancers of a particular type in the population of nearby residents;this is the province of the field of epidemiology. If a pollutant persists in the environment, calculation ofits ultimate effect may require integration of its impacts over the time during which it is biologically active(that is, has an effect on the environment). In many cases using dose response models may involvecomparing known doses to existing empirical dose-response data119.

6.4 Some Simplified Indices And Selected Standards

6.4.1 Global Warming Potentials

Simpler models and relationships, however, have been used to estimate, for example, the specific"radiative forcing" (change in the global heat balance) attributable to changes in the concentrations ofgreenhouse gasses in the atmosphere120. The results of some of these models, plus some results ofatmospheric chemistry models, have contributed to sets of relationships that allow the relative climate-changing ability of emissions of different greenhouse gasses to be compared. These relationships arecalled Global Warming Potentials, or GWPs. GWPs can be (with care) applied directly to estimates ofemissions of the different species of greenhouse gasses to produce an overall estimate of warming potential,often expressed in kilograms of CO2 or kilograms of carbon, for emissions from a given country or region(for example) per unit time. Table 6.5, below, provides some of the estimates of Global WarmingPotential published by the Intergovernmental Panel on Climate Change, or IPCC.

Table 6.5Global Warming Potentials Relative to CO2 Reference

(100 year time Horizon; Selected Compounds; Source: IPCC, 1994)Species Chemical Formula Lifetime (yrs) GWPCarbon Dioxide CO2 50 - 200 1Methane CH4 12-17 (adjustment time) 24.5Nitrous Oxide N2O 120 320CFC-11 CFCl3 45 - 55 4000CFC-12 CF2Cl2 102 8500CFC-13 CClF3 640 11700CFC-113 C2F3Cl3 85 5000CFC-114 C2F4Cl2 300 9300CFC-115 C2F5Cl 1700 9300HCFC-22 CF2HCl 13.3 1700HCFC-123 C2F3HCl2 1.4 93Carbon Tetrachloride CHCl3 42 1400HFC-134a CH2F2CF3 14 1300

119These type of data are available from many sources. One compendium where one can find a variety of data on the humanhealth effects of a number of different pollutants is Doull, J.D, C.D. Klaassen, and M.O. Amdur, editors, Casarett and Doull'sToxicology, Second Edition, 1980, Macmillan Publishing Co., N.Y., N.Y., USA, pages 317 - 319.120See for example Lashof, D.A., and D.R. Ahuja, Nature, 5 April 1990, pp. 529-531.


6.4.2 Air Quality Indices

In some nations and local areas, indices of air quality are used to translate the sometimes confusingjargon of hourly and daily concentrations for specific pollutants into a general indicator of the health risksof outside air on a given day. When an index exceeds a certain value, activities such are playing orworking outside for extended periods are discouraged, and residents are urged to take special precautions.

6.4.3 WHO Environmental Standards

The World Health Organization publishes sets of guidelines for air pollutant concentrations ininhabited areas. When local conditions exceed these standards--which are specified as maximum averageconcentrations over various periods of time (including hourly, daily, and annual averages) of specificpollutants such as particulate matter, nitrogen dioxide, ozone, and others--it is an indicator of poor ordeclining air quality. A summary of these air quality guidelines (from WHO/UNEP 1994) is provided asTable 6.6121.

Table 6.6Summary of WHO Air Quality Guidelines (Source: WHO/UNEP, 1994)

Pollutant Time-weighted Average Unitsa Averaging TimeSulfur Dioxide 500 µg/m3 10 minutes

350 µg/m3 1 hour100 - 150 b µg/m3 24 hours

40 - 60 b µg/m3 1 yearCarbon Monoxide 30 mg/m3 1 hour

10 mg/m3 8 hoursNitrogen Dioxide 400 µg/m3 1 hour

150 µg/m3 24 hoursOzone 150 - 200 µg/m3 1 hour

100 - 120 µg/m3 8 hoursSuspended Particulate Matter Black Smoke 100 - 150 b µg/m3 24 hours

40 - 60 b µg/m3 1 year Total Suspended Particulates 150 - 230 b µg/m3 24 hours

60 - 90 b µg/m3 1 year Thoracic Particles (PM10) 70 b µg/m3 24 hoursLead 0.5 - 1 µg/m3 1 yearNotes:a Milligrams (mg/m3) or micrograms (µg/m3) of pollutant per cubic meter of air.b Guideline values for combined exposure to sulfur dioxide and suspended particulate matter (they may notapply to situations where only one of the components is present).

121 Note that these guidelines are contained (as referenced in WHO/UNEP, 1994) in a series of 1977 through 1979 WHO“Environmental Health Criteria” reports (numbers 3, 4, 6, 8, and 13), each of which covers particular classes of pollutants.


6.5 Suggested Resources for Environmental Modeling

• The US EPA maintains a “Clearinghouse” of tools for modeling of air quality. Information on theattributes of a number of models is available from the USEPA Office of Air Quality Planning andStandards in the Office of Air and Radiation, USEPA, Research Triangle Park, North Carolina, USA.Many computer-based air quality modeling tools are also available from this source, as well asdocumentation on how (and how not) to use them. Some of the models and information is availablethrough a computerized “bulletin board” called “SCRAM” that interested parties can reach via modem.Please see Appendix B for further USEPA information on air quality models.

• The World Health Organization’s Assessment of Sources of Air, Water, and Land Pollution: A Guide

to Rapid Source Inventory Techniques and their Use in Formulating Environmental ControlStrategies. (Economopolous, 1993). This two-volume manual provides several simple models andmethods specifically designed for planners with limited resources, and is available in several languages.

• The report Externalities Screening and Recommendations, prepared for the New York State

Environmental Externalities Cost Study by a team headed by RCG/Hagler, Bailly, Inc. (1993),includes summaries of air quality models and of the impacts of air and water pollutants, solid wastedisposal, and other environmental impacts of energy systems.

• The book, Consider a Spherical Cow: A Course in Environmental Problem Solving, by John Harte of

the University of California at Berkeley (Harte, 1985), contains a wealth of insights on the basicapproaches for modeling environmental processes.

The series of reports prepared under the USEPA’s “Atmospheric Stabilization Framework” effort (seeUSEPA, 1990c) and entitled Policy Options For Stabilizing Global Climate includes the review andapplication of a number of different models related to climate change (see the Technical Appendix to thePolicy Options.. reports). Some of these models have, in the past, been available from the USEPA oncomputer diskettes.

References 131

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139

APPENDIX A:

ANNOTATED LIST OF LITERATURE REFERENCES USED INCOMPILING THE ENVIRONMENTAL DATABASE (EDB)

Author: Air Resources Board - State of CaliforniaYear: 1982Title: Methods for Assessing Area Source Emissions in CaliforniaPublisher: Air Resources Board - State of CaliforniaOther Info: Includes all revisions through December 1984

Notes: Includes emission factors for various types of "area sources" -- sources of emissions thatindividually release small amounts of a pollutant but collectively release significant emissions --in both the energy and non-energy sectors. Sources of emissions covered range from asphaltroofing to residential fuel use to open burning of agricultural wastes. Data for many sources arederived from values obtained from the USEPA (see the EPA "AP-42" document referencedbelow), but specific values for and from California are included as well. A September 1991Update is available. [0 M]

Author: Air Resources Board - State of California (CARB)Year: 1990Title: Instructions for the Emission Data System Review and Update Report. Appendix III: Source

Classification Codes and EPA/NEDS Emissions Factors.Publisher: Air Resources Board - State of CaliforniaOther Info: Dated March 1990.

Notes: Provides two sets of emission factors: 1) emission factors used by EPA for the NationalEmission Data System (NEDS) as published in "Criteria Pollutant Emission Factors for the 1985NAPAP Emissions Inventory," and 2) emission factors based on information in the EPA AP-42document (referenced below). [0 A]

Authors: Bocola W. and Cirillo M.C.Year: 1989Title: Air pollutant emissions by combustion processes in Italy.Publisher: In Atmospheric Environment, Vol. 23, 227-245

Notes: Includes emission factors used in compiling inventory of air emissions for Italy. Most airemission values are from the CORINAIR Database. [0 A]


Author: Bose, R.K., and V. SrinivasacharyYear: 1991Title: Policies to Reduce Energy Use and Environmental Emission in the Transport Sector: A Case of

Delhi City.Publisher: Tata Energy Research Institute, New Delhi, IndiaOther Info: Unpublished manuscript

Notes: Provides emission factors used in analysis conducted with LEAP/EDB, while Dr. Bose was avisiting Scientist at the UNEP Centre, RISO National Lab, Denmark. These emission factors areapplicable to vehicles in India and perhaps other developing countries. One of the maintechnical sources used was the Indian Institute of Petroleum report, "State of Art Report onVehicle Emissions," Dehradum, 1985. [0 A]

Authors: Butcher, S., Rao, U., Smith, K.R., Osborn, J., & Azuma, P.Year: 1984Title: Emissions Factors and Efficiencies for Small-scale Open Biomass Combustion: Toward

Standard Measurement TechniquesPublisher: Annual Meeting of the American Chemical Engineering Society

Notes: Describes methods for collecting emissions data for small biomass combustion sources, includingresidential biomass stoves. Includes limited emissions data based on field measurements.

[2 M]

Author: California Air Resources BoardYear: 1986Title: [still need to enter the complete reference]Publisher:Other Info: [40 M]

Author: California Air Resources Board (CARB)Year: 1991Title Identification of Volatile Organic Compound Species Profiles: ARB Speciation Manual,

Second Edition.Publisher: CARB, Sacramento, California, USAOther Info: Volume 1 of 2

Notes: Provides data to estimate the emissions of specific species of volatile organic compounds (VOCs)assuming that an overall VOC emission factor is available. Both energy and non-energy-sectorsources are covered, with different numbers of specific organic compounds identified per source.Includes data from the USEPA as well as California-specific information. [10 M]

141

Author: California Energy Commission, Existing Power PlantsYear: 1989Title: Emission Factors for Existing California and Existing Out of State Power PlantsPublisher: California Energy Commission, Sacramento, California, USAOther Info: Final Version

Notes: Provides emission factors for current stock of power plants in California and other WesternStates. [80 M]

Author: California Energy Commission, Generic Power PlantsYear: 1989Title: Staff Recommendations for Generic Power Plant Emission FactorsPublisher: California Energy Commission, Sacramento, California, USAOther Info: Final Version

Notes: Summary information for air pollutant emission factors for generic new power plants. Coversboth conventional fossil-fueled plants and some newer technologies (e.g. combined-cycle andbiomass-fueled plants). [6 M]

Author: California Energy Commission, Characterization WorksheetYear: 1990Title: Electric Generation Characterization WorksheetPublisher: California Energy CommissionOther Info: DRAFT, not to be quoted [0 M]

Author: Centre D'Etude sur L'Evaluation de la Protection dans le Domaine Nucleaire (CEPN)Year: 1987Title: BATEX user manualPublisher: CEPN, Fontenay-aux-Roses (Near Paris), FranceOther Info: Model of accidental releases (document is in French).

Notes: User's Guide to BATEX model of dispersion of materials accidentally released to the air (e.g. viaan explosion). [0 M]

Author: Commission of European CommunitiesYear: 1988Title: Radiation Protection - The Impact of Conventional and Nuclear Industries on the

Population: A Comparative Study of the RadioactivePublisher: CEC Directorate General for Science, Research and Development, Brussels, BelgiumOther Info: Report Number EUR 10557 EN Contract BIO.F.320.81.F

Notes: Contains information on radioactive emissions from energy technologies. [0 M]

Author: Corinair Inventory -- Commission of the European Community


Year: 1992Title: Default Emission Factor Handbook.Publisher: Commission of the European Community, Brussels, BelgiumOther Info: Updated periodically

Notes: CORINAIR is an international (EC member states) effort to assemble consistent nationalinventories of air pollutant emissions, including sulfur and nitrogen oxides, and VOCs. Thisdocument presents the emission factors used in this effort, which covers stationary (e.g. powerplants, industrial facilities, household emissions), agricultural, road transportation (broken downinto hot emissions, cold starts, and evaporative emissions ), and natural sources. These sourcesinclude some non-energy sector activities. This documents is one of the primary Europe-specificsets of emission factor data. Gordon Mackenzie and Mette S. Olufsen at the UNEP CollaboratingCentre on Energy and Environment, at RISO National Laboratory in Denmark, used data in thisdocument to set up the EDB Corinair demand/transformation data. [1154 A]

Authors: DeLuchi, M.A, Johnston, R.A, Sperling, D.Year:Title: Transportation Fuels and the Greenhouse EffectPublisher: Division of Environmental Studies, University of. California, Davis, CA, USAOther Info: Transportation Research Record 1175 p33

Notes: Provides a comparison on the relative greenhouse-gas emissions from both conventional andbiomass-based transportation fuels. [0 M]

Authors: DeLuchi, M.A, Johnston, R.A, Sperling, D.Year: 1988Title: Methanol versus Natural Gas Vehicles: A Comparison of Resource Supply, Performance,

Emissions, Fuel Storage, Safety, Costs and TrPublisher: University of California, Davis, CA.Other Info: SAE Technical Paper Series 881656 - International Fuels and Lubricants Meeting and

Exposition, Portland, Oregon, Oct. 1988

Notes: Includes emission factor information on methanol and natural gas vehicles. These authors havepublished widely on the topic of alternative-fuel vehicles. [0 A]

143

Author: DeLuchi, M.A.Year: 1991Title: Emissions of Greenhouse Gases from the Use of Transportation Fuels and Electricity, Volumes 1

& 2.Publisher: Center for Transportation Research, Argonne National LaboratoryOther Info: Dated November 1991. Report number ANL/ESD/TM-22, Vol. 1 & 2. DeLuchi is

affiliated with the Institute of Transportation Studies, University of California, Davis.

Notes: Provides estimate of the full fuel-cycle emissions of greenhouse gases from transportation fuelsand electricity. Covers emissions of carbon dioxide, methane, carbon monoxide, nitrous oxide,nitrogen oxides, and non-methane organic compounds. Compares emissions from gasoline anddiesel fuels cycles with emission from: methanol from coal, natural gas, or wood; compressed orliquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefiedpetroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity fromcoal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electricvehicles; and hydrogen and methanol used in fuel-cell vehicles. [0 A]

Authors: Dohan, M.R, Philip, P.F, with Lee, J, and Smith, M. Energy Systems Analysis Group(BNL) and Urban and Policy Sciences Program (SUNY)

Year: 1974Title: The Effect of Specific Energy Uses on Air Pollutant Emissions in New York City: 1970-

1985Publisher: Brookhaven National Laboratory, BNL/ SUNY New York Regional Energy Study, New

YorkOther Info: BNL Report Number 19064

Notes: Commonly cited early source of emission factors on which data in some later compendia arebased. [0 M]

Author: Economopoulos, Alexander P.Year: 1993Title: Assessment of Sources of Air, Water, and Land Pollution: A Guide to Rapid Source Inventory

Techniques and their Use in Formulating Environmental Control Strategies.Publisher: World Health Organization, Geneva, SwitzerlandOther Info: This is a two part report. Part One: Rapid Inventory Techniques in Environmental Pollution.

Part 2: Approaches for Consideration in Formulating Environmental Control Strategies.WHO/PEP/GETNET/93.1A & B.

Notes: This document updates the 1982 WHO document listed below. It provides a comprehensiveapproach for evaluating air emission inventories and controls, liquid waste inventories andcontrols, and solid waste inventories. It presents metrologies which can be used to make aninitial appraisal of the sources and levels of emissions from an area that has little or no previouspollution load data -- i.e. particularly in developing countries. It relies on data from Corinair, theUSEPA AP-42 documents, and other sources. [0 A]

Author: Ellegard, AndersYear: 1989


Title: Air Pollution and Coal Use in Maputo: Maputo Coal Stove Project: Summary ofEnvironmental Investigations

Publisher: Beijer Institute/Stockholm Environment InstituteOther Info: Final version based on "COAL STOVE EMISSIONS: Results From Investigations at the

Swedish Testing Institute", working paper #7, 1988

Notes: Provides measured emission factors for household coal-fired stoves (data collected in Africa),with limited additional data for biomass-fired stoves. [39 A]

Author: Ellegard, Anders, and Jose LopesYear: 1990Title: Quick and Dirty: The Maputo Coal Stove Project 1985-89Publisher: Stockholm Environment InstituteOther Info: SEI Energy, Environment and Development Series Report No. 1. Published in

collaboration with the Swedish International Development Authority (SIDA).\

Notes: Provides measured emission factors for household coal-fired stoves (data collected in Africa),with limited additional data for biomass-fired stoves. [0 A]

Author: Expertengruppe Energieszenarien/ Groupe d'Experts Scenarios EnergetiqueYear: 1988Title: Energieszenarien/ Scenarios EnergetiquesPublisher: Expertengruppe Energieszenarien/ Groupe d'Experts Scenarios EnergetiqueOther Info: Mogliuchkeiten, Voraussetzungen und Konsequenzen eines Ausstiegs der Schweiz aus der

Kernenergie/ (In French and German)

Notes: Provides energy scenarios and some emission factors for Switzerland in the context of aprospective study of emissions for the country. [0 M]

Authors: Gleick P.H., Morris G.M., Norman A.N.Year: 1989Title: Greenhouse Gas Emissions from the Operation of Energy FacilitiesPublisher: Prepared for the Independent Energy Producers Association, Sacramento, CA, USA.

Notes: List emission factors for several types of greenhouse gasses for different types of EnergyFacilities, with an emphasis on electric power plants of types used in or proposed for California.

[0 M]

145

Authors: Holdren J. P., G. Morris, and I. MintzerYear: 1980Title: Environmental Aspects of Renewable Energy SourcesPublisher: In Annual Review of Energy, 1980, v.5 p. 241-291

Notes: Fairly comprehensive early work on full-fuel cycle emissions from renewable energy systems,including biomass energy and other solar energy fuel cycles. [0 A]

Author: ICF IncorporatedYear: 1989Title: ASF - The Atmospheric Stabilization Framework User's Guide and Software DescriptionPublisher: ICF Incorporated, Fairfax, Virginia, USAOther Info: 1989 Version in Draft Form - Contains data files of emission factors used in USEPA's

ASF study.

Notes: User's Guide contains a wealth of information on models of greenhouse gas emissions and effectsand on background data for ASF's global inventory of GHGs, as well as the emission factor datafiles for select greenhouse gas emissions (carbon dioxide, carbon monoxide, nitrogen oxides,nitrous oxide, methane) from a wide variety of sources of GHGs. Also contains data on theeffectiveness of technologies for reducing GHG emissions. Most of the emissions data includedhere were derived from earlier versions of Radian, 1990, and from other USEPA documents.Some of the materials in this volume were subsequently published as a "Technical Appendix"Volume to the USEPA study Policy Options for Stabilizing Global Climate, USEPA ReportNumber 21P-2003.3, December, 1990. [0 A]

Author: ICF Resources IncorporatedYear: 1990Title: Methane Emissions to the Atmosphere from Coal MiningPublisher: ICF Resources Inc., Fairfax, VAOther Info: Report to USEPA Office of Air and Radiation; released as USEPA report number

EPA/400/9-90/008, September, 1990. USEPA, Washington, D.C., USA.

Notes: Provides emission factors for surface and underground mining, plus a discussion of emissions ofmethane from coal mining in each mining state of the United States and from other major coal-producing nations. Also provides a discussion of the factors that influence methane emissionsfrom coal mining. [12 M]

Author: IEA and OECDYear: 1990Title: Climate Change: The Energy DimensionPublisher: The International Energy Agency and the Organization for Economic Co-operation and

Development (IEA and OECD), Paris, France.Other Info: Emission factor data largely based on Radian 1987.

Notes: [0 A]


Author Intergovernmental Panel on Climate Change (IPCC)Year 1990Title: International Workshop on Methane Emissions from Natural Gas Systems, Coal Mining,

and Waste Management Systems", April 9-13, 1990.Publisher: Workshop funded by the Environment Agency of Japan, USAID, and USEPA.Other Info: Document available through the USEPA Office of Policy, Planning and Evaluation--

Climate Change Division.

Notes: The papers presented provide data on methane emissions from the indicated sources. Someestimates of national and global average emission factors and leakage rates are presented. Asummary of this workshop was published as Methane Emissions and Opportunities for Control,USEPA report number EPA/400/9-90/007, September 1990. [10 M]

Author: Islam, N.Year: 1987Title: Test of Combustion Properties and Pollutant Emissions of Lignite BriquettesPublisher: Resource Systems Institute, East-West Center, Honolulu, Hawaii, USAOther Info:

Notes: Provides emissions test data for combustion of lignite (coal) briquettes of types that could be usedin household coal stoves in developing countries. [3 M]

Author: Meridian CorporationYear: 1988Title: Energy System Emissions and Material RequirementsPublisher: Prepared for US Department of Energy, Washington DC, USAOther Info: DRAFT - for the Deputy Assistant Secretary for Renewable Energy, DOE

Notes: Provides information on the relative environmental emissions and material requirements ofseveral different energy systems, including both renewable and fossil-fueled technologies.

[0 M]

Authors: Mintzer I., Hedman S., Miller A., Bowser R.Year: 1990Title: Externalities Associated with Electric Power Supply and Demand-Side TechnologiesPublisher: Center for Global Change, University of Maryland, College Park, MD, USAOther Info: Working Paper

Notes: Provides information on the relative environmental emissions and other externalities associatedwith options for both saving electricity through demand-side management technologies and forgenerating electricity using power plants. Emission factors and technological comparisons areprovided for a number of different systems. [0 M]

Author: Morris, S.C, Novak, K.M. (Regional Energy Studies Program, BNL)Year: 1977Title: Databook for the Quantitative Health Effects From Coal Energy Systems

147

Publisher: Brookhaven National Laboratory (BNL)/ US Department of Energy (USDOE)Other Info: For National Coal Utilization Assessment BNL 23606 Information Report, 1977

Notes: Early work describing health effects of coal energy systems. Part of a large energy andenvironment modeling project that took place at BNL in the 1970's and 1980's. [0 M]

Author: Moscowitz, C. M.Year: 1978Title: Source Assessment: Charcoal Manufacturing, State of the ArtPublisher: Environmental Protection AgencyOther Info:

Notes: Provides air pollutant emission factors for several types of commercial US charcoal-making kilns.[18 M]

Author: OECD, Air Policy Management GroupYear: 1988Title: The Motor Vehicles Project: Control of Emissions from In-use Vehicles: Technical

Background PaperPublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France.Other Info: Meeting Room Document. No. 1 for the 37th meeting, Paris, 25-26 Oct.

Notes: [0 M]

Author: OECD, Air Policy Management GroupYear: 1989Title: Control of Major Air Pollutants - A Study of Long Range Transport of Photochemical

Oxidants Across EuropePublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France.Other Info: ENV/AIR/88.8 (1st version) - Restricted - Also published from the 37th meeting, 25-26

Oct.

Notes: Focus is on the fate of acid rain precursors (nitrogen and sulfur oxides) emitted in Europe.Includes some limited emission factor data for NOx and SOx emissions from major sources.

[0 M]


Author: OECD, Compass ProjectYear: 1983Title: Environmental Effects of Energy SystemsPublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France. OECD, ParisOther Info:

Notes: This document is a mostly-qualitative summary of the environmental externalities associatedwith the construction and use of energy systems, with some limited quantitative data on airemissions and other environmental impacts. [0 A]

Author: OECD, Compass ProjectYear: 1985Title: Environmental Effects of Electricity GenerationPublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France. OECD, ParisOther Info:

Notes: A primarily descriptive summary of the environmental effects of electricity generation, with somelimited generic quantitative data on power plant emission factors. [0 A]

Author: OECD, Compass ProjectYear: 1986Title: Environmental Effects of Automotive Transport.Publisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France. OECD, ParisOther Info: 172 pp.; published in English

Notes: This document provides a mostly-qualitative summary of the environmental effects of automotivetransport, primarily from a developed-country point of view. Some generic emission factors areprovided for typical European motor vehicle. [7 A]

Author: OECD, Compass ProjectYear: 1988Title: Environmental Impacts of Renewable EnergyPublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France.Other Info:

Notes: Like the other volumes in the "Compass" series this document provides a qualitative summary ofthe environmental effects of renewable energy systems, with a few examples in which impacts oremissions are quantified. [0 A]

149

Author: OECD, Environment Directorate, Air Policy Management GroupYear: 1989Title: Control of Major Air Pollutants - Emissions Inventory for OECD EuropePublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France.Other Info: From the 37th meeting of the Group, 25-26 Oct.. Not a final draft. Marked

RESTRICTED

Notes: Documents the process used to produce a preliminary inventory of air pollutants for OECDEurope. Includes a listing of the emission factors used to produce the inventory. Many of thefactors used were derived from USEPA figures, although much Europe-specific information isalso included. [0 M]

Author: ÖKO InstituteYear: 1990Title: TEMIS model and miscellaneous papersPublisher: ÖKO Institute, Darmstadt, GermanyOther Info: TEMIS is the Total-Emission-Model for Integrated Systems. TEMIS has been released in

the US in cooperation with the USDOE. Most of the papers and manuals coveringTEMIS are available in both English and German.

Notes: TEMIS is a software tool designed to compare the relative fuel cycle energy use and emissionsthat occur as a consequence of using alternative methods providing an energy service. Anexample application might be the comparison of emissions per GJ of heat delivered home heatingusing fuel oil versus home heating using electric resistance heat. TEMIS includes a database ofemission factors for several key air pollutants, plus solid wastes and some other environmentalimpacts. This database includes quantitative information from many sources, including a gooddeal of emission factor information from Germany. [0 A]

Author: ORNL: Oak Ridge National Laboratory, G. Marland et al.Year: 1989Title: Estimates of CO2 Emissions from Fossil Fuel Burning and Cement Manufacture...Publisher: ORNL/CDIAC (Carbon Dioxide Information Analysis Center), Oak Ridge National

Laboratory, Oak Ridge, TN, USAOther Info: Report # ORNL/CDIAC-25

Notes: This volume presents estimates of carbon dioxide emissions from the combustion of solid, liquid,and gaseous fossil fuels, as well as from natural gas flaring from oil wells and from cementproduction, for virtually all countries of the globe. Data sets start as early as 1950, and runthrough 1987 (data for later years are available in diskette form). Estimates for energy sectorcarbon dioxide emissions are based on energy production and import/export data obtained fromthe United Nations. This volume includes general carbon dioxide emissions factors for fossilfuels and for cement manufacture that are widely used by other researchers in the climate-changefield. and also includes a thorough write-up of how the ORNL emissions inventory, and theemission factors used in it, are derived. [56 A]

Author: PASZTOR, J. and KRISTOFERSON, L. (eds)Year: 1990


Title: Bioenergy and the EnvironmentPublisher: Westview Press, Boulder CO., USAOther Info:

Notes: This book provides an overview of many of the environmental issues surrounding the productionand use of biofuels. It is divided into sections focusing on "The Fuels" (e.g. traditional fuels,modern fuels, liquid fuels, biogas) and "Effects on the Environment" (air pollution, waterpollution, socioeconomic impacts, and others). Both qualitative and quantitative information isprovided, including some emissions coefficients for biomass combustion and other biomassenergy systems. [2 A]

Author: Radian CorporationYear: 1987Title: 1987 Symposium on Stationary Combustion Nitrogen Oxide ControlPublisher: Radian Corporation, Research Triangle Park, North Carolina, USAOther Info: Volumes I and II

Notes: Includes papers that describe options for control of nitrogen oxide (NOx) emissions, withtechnology descriptions, and estimates of the percentage reduction in NOx emissions through useof the control devices, and, in some cases, estimates of the costs of pollution control equipment.

[0 M]

Author: Radian CorporationYear: 1990Title: Emissions and Cost Estimates for Globally Significant Combustion Sources of NOx,

N2O), CH4, CO, and CO2.Publisher: US EPA, Office of Policy, Planning, and Evaluation.Other Info: EPA Report # EPA-600/7-90-010, May 1990, EPA Contract No. 68-02-4288

Notes: Includes emission factors for the greenhouse gasses (GHG) listed above for combustion of fuelsby equipment in the utility, industrial, fuel production, transportation, residential, andcommercial sectors, as well as for large industrial kilns, ovens, and dryers. Also included aredata on the relative costs and efficiency of devices and technologies for controlling GHGemissions. This document is the source of much of the emission factor data used in the USEPA'sAtmospheric Stabilization Framework study, as well as other inventory efforts. Most of the(non-CO2) emission factors contained here are derived from the USEPA "AP-42" emission factorcompendium. [3 M]

151

Author: Radian Corporation (Weaver, C.S, Klausmeier, R.F, Kishan, S.)Year: 1986Title: Estimation of Energy-Specific CO and NOx Emission Factors for the World Vehicle Fleet:

1960-2025Publisher: Radian Corporation, Sacramento, CA, USAOther Info: Dated March 6, 1986. Prepared. under EPA Contract No. 68-02-3994.

Notes: Provides estimates of past, present and future emission factors for carbon monoxide and nitrogenoxides, two of the most important pollutants from automobile engines, for the world's vehiclefleet. Emissions factors are provide for 6 regions (USA; Western Europe/Canada;Japan/Australia/New Zealand; Soviet Union/Eastern Europe; China; and Rest of World).Estimates of CO and NOx emissions were developed for a number of generic automotivetechnologies using emissions and fuel-economy data from EPA's MOBILE3 model (i.e. theUSEPA "AP-42" Vol. 2 emission factor compendium). [0 A]

Author: Radian Corporation, Research Triangle Park, N.C.Year: 1987Title: Criteria Pollutant Emissions Factors for the 1985 NAPAP (National Acid Precipitation

Assessment Program) Emissions InventoryPublisher: U.S. National Technical Information Service, Springfield, VAOther Info: USEPA Report # EPA/600/7-87/015; NTIS Report # PB87-198735

Notes: This database, which is primarily derived from the USEPA AP-42" series of reports, presents inconcise form emission factors for the "criteria" air pollutant emissions (nitrogen and sulfuroxides, VOCs, carbon monoxide, particulate matter, and in some cases lead) for stationarysources of emissions. These sources of emissions include facilities and equipment in both theenergy sector as well as industrial and other non-energy processes (e.g. solvent use, sintering ofmetals, manufacture of chemicals). [0 A]

Author: Safriet D.W. - EPA project officerYear: 1989Title: Estimating Air Toxic Emissions from Coal and Oil Combustion SourcesPublisher: EPA, Research Triangle Park, NC, USAOther Info: EPA-450/2-89-001

Notes: Provides methods, emission factors and speciation fractions (i.e. what fraction of totalhydrocarbons is made up of a specific toxic hydrocarbon species) to enable the estimation ofemission factors for toxic substances derived from oil and coal combustion. [0 M]


Author: Smith, Kirk R.Year: 1987Title: Biofuels, Air Pollution, and Health: A Global ReviewPublisher: Plenum Press, New York, N.Y., USA

Notes: Excellent review of the environmental and human-health impacts of biofuels use, with aparticular emphasis on environmental and health effects in developing countries. Also containssome secondary source material that is otherwise difficult to obtain on emissions factors for coaland biofuel consumption in the types of household stoves found in developing countries. [94 M]

Author: Smith, Kirk R., et al.Year: 1992Title: Greenhouse Gases from Biomass and Fossil Fuel Stoves in Developing Countries: A Manila

Pilot Study.Publisher: Chemosphere

Notes: Discusses the results of tests on a total of 24 samples, 14 cookstoves. The cookstoves tested werefueled by LPG, kerosene, charcoal, and wood. Emissions of carbon dioxide, carbon monoxide,methane, nitrogen oxides, and total non-methane organic compounds were analyzed. The authoris currently conducting larger more detailed studies in India and China. [0 A]

Author: Smith, Kirk R., et al.Year: 1992Title: Greenhouse Gases from Small-Scale Combustion in Developing Countries: A Pilot Study in

Manila .Publisher: U.S. Environmental Protection Agency, Office of Research and DevelopmentOther Info: EPA report: EPA-600-R-92-005.

Notes: Discusses the results of tests on a total of 24 samples, 14 cookstoves. The cookstoves tested werefueled by LPG, kerosene, charcoal, and wood. Emissions of carbon dioxide, carbon monoxide,methane, nitrogen oxides, and total non-methane organic compounds were analyzed. Reportincluded detailed results from the tests. [0 A]

Authors: Sperling, D, DeLuchi, M.A.Year: 1989Title: Transportation Energy FuturesPublisher: University of California, Davis, CA, USAOther Info: Also in Annual Review of Energy, 1989.

Notes: Provides a forward-looking view of transportation systems and technologies, particularly for theUnited States and other developed countries. Provides some limited information on emissionfactors for new and upcoming vehicles, including those using fuels other than diesel oil andgasoline-fueled transportation. [0 A]

Author: Stockholm Environment Institute - Boston Center (TELLUS Institute)Year: 1990

153

Title: Calculated based on assumptions listed in note for specific entryPublisher: (None)

Notes: This note indicates that the value, rather than being derived from a specific reference document,was estimated by the Stockholm Environment Institute--Boston Center based on specificassumptions as listed in the notes for the specific entry. [357]

Author: Stockholm Environment Institute--Boston Center (Tellus Institute)Year: 1991Title: Calculations based on fuel carbon contentPublisher: (None)

Notes: This note indicates that the value, an estimate of carbon dioxide emissions per unit fuelconsumed, has been calculated at the Stockholm Environment Institute--Boston Center based onfuel carbon-content assumptions as listed in the notes for the coefficient entry, and was thus notbased directly on any one particular literature source. Most of the carbon dioxide coefficients inEDB were calculated in this manner, using default carbon content assumptions from LEAP, so ato create a consistent set of CO2 emission factors within EDB. [54]

Author: Stockholm Environment Institute--Boston Center (G2S2)Year: 1991Title: The Greenhouse Gas Scenario System (G2S2: Current Accounts Spreadsheet

ENERGY.XLS)Publisher: Stockholm Environment Institute--Boston Center (SEI-B), Boston, MA, USAOther Info: G2S2 Spreadsheet as of July, 1991.

Notes: In the process of preparing the Greenhouse Gas Scenario System, a tool for estimating national,regional. and global inventories of greenhouse gasses, estimates were made of national andregional-average emission factors for various sectors, based primarily on energy data from theOECD/IEA and on emission factors from the Atmospheric Stabilization Framework and othersources. Some of these values are available as generic estimates in EDB. [516]

Author: Tellus Institute (Vermont Report)Year: 1990Title: The Role of Hydro-Quebec Power in a Least-Cost Energy Resource Plan for VermontPublisher: Tellus Institute, Boston, MA, USAOther Info: [26]


Author: Tellus Institute - Internal E-factorsYear: 1990Title: Master Emissions List for New Generic Facilities.Publisher: Tellus Institute, Boston, MA, USAOther Info: [0]

Author: Tellus Institute - Manchester Street ReportYear: 1990Title: Evaluation of Repowering the Manchester Street StationPublisher: Tellus Institute, Boston, MA, USAOther Info: [4]

Author: U. S. Congress, CAAYear: 1990Title: Amended Clean Air ActPublisher: U. S. Government Printing Office, Washington, D.C., USAOther Info:

Notes: Describes 1990 United States regulations governing air pollutant emissions from energycombustion and from other sources. For some sectors, provides maximum emission factorspermissible in the US for new and refurbished energy-using equipment. [38]

Author: U.S Environmental Protection Agency (USEPA) (Speciate)Year: 1990Title: Volatile Organic Compound (VOC)/Particulate Matter (PM) Speciation Data System.

Version 1-32aPublisher: USEPA. Research Triangle Park, NC, USAOther Info: Prepared by Radian Corporation for USEPA. EPA Contract # 68-02-4286

Notes: Computer database allowing estimation of atmospheric emission factors for particular organicspecies and for specific size classes of particulate matter emissions (e.g. particulate emissionsunder or over ten microns in diameter). Speciation profiles (or surrogate profiles) are availablefor most of the sources of emissions described in the USEPA's "AP-42" series. In many cases,profiles that have been measured for one source are used as default or surrogate values for similartypes of equipment. This database is available as part of the "AIR CHIEF" CD-ROM (opticaldata storage) disk distributed by the EPA, and also as a part of the "CHIEF" computer bulletinboard system, run by the EPA from its Research Triangle Park office. [11 M]

155

Author: U.S. Department of Energy (ETH)Year: 1983Title: Energy Technology Characterizations Handbook (ETH). Environmental Pollution and

Control Factors. Third Edition.Publisher: U.S. Department of Energy, Off. of Environmental Analysis, Washington D.C., USAOther Info: Report # DOE/EP-0093

Notes: Large, well-referenced volume providing 1) characterizations of the fuel use, energy output,materials and resource requirements (e.g. steel, land, water), and environmental "residuals" (airpollutants, solid wastes, radiation, water-borne pollutants, health and safety) for severalcategories of technologies, including nuclear, synthetic fuel, coal, petroleum, natural gas, solar,geothermal, and hydroelectric technologies, and 2) characterizations of environmental controltechnologies for coal-fired utility and industrial plants and for synthetic fuels technologies. Mostof the equipment discussed is of utility scale, and is geared to large-scale production of eitherelectricity or liquid fuels. This work is a good reference for environmental emission factorsbeyond air pollutant emissions, though not every type of environmental impact is considered forevery type of energy system characterized. This volume had not been updated as of 1992.

[100 M]

Author: U.S. Department of Energy/Energy Information Administration (SEDS)Year: 1985Title: State Energy Data Report (SEDS)Publisher: DOE/EIA, Washington D.C., USAOther Info:

Notes: Presents data on energy use by state and sector for each state of the United States. Thisinformation is the basis of the NAPAP (National Acid Precipitation Assessment Program)Emissions Inventory done on an annual basis. [103 M]

Author: U.S. Department of Energy, Office of Environmental AnalysisYear: 1988Title: Energy Technologies and the Environment. Environmental Information HandbookPublisher: National Technical Information Service, Springfield, VA, USAOther Info: Report # DOE/EH-0077, dated 10/88

Notes: This handbook covers many of the same technologies presented in the 1983 USDOE publicationEnergy Technology Characterizations Handbook, as described above, but in a somewhatdifferent (more narrative) format. The 21 chapters cover coal-based, petroleum refining, oil-shale, fuel cell, nuclear, solar, and biomass technologies, as well as advanced diesel engines.Each chapter provides a narrative description of the technology and its environmental impacts,with quantitative data on emissions and other impacts that varies in amount and coverage bychapter. The handbook is a good source for those wishing an overview of specific (typicallylarge-scale) energy technologies and their environmental risks. [54 M]


Author: U.S. Environmental Protection Agency (AP-42, Vol I)Year: 1985Title: Compilation of Air Pollutant Emission Factors. Volume I: Stationary Point and Area

SourcesPublisher: National Technical Information Service, Springfield, VA, USAOther Info: Volume I of report # AP-42, 4th edition; Updated frequently

Notes: "AP-42" is the USEPA's central compilation of air pollutant emission factors for virtually allsignificant sources of air pollution. Volume I of this series, together with its many supplements,provides emission factors for a wide variety of both fuel-using and non-energy stationaryequipment, appliances, facilities and processes. The technologies covered range from coal-firedpower plants to propane heaters to charcoal kilns to processes for manufacturing specificchemicals. The information in AP-42 is drawn on heavily by many other US and internationalemission factor databases. Most of the information in AP-42 is based on the results ofemissions testing--tests commissioned by EPA or other agencies or reported in the scientificliterature. AP-42 provides qualitative guidelines (lettered "A" though "E") indicating the qualityof data for most sources. Most of the information in AP-42 is available on the AIR CHIEF CD-ROM (optical data storage) disk, and through the CHIEF computer bulletin board system.Information on both of these products can be obtained through the USEPA office in ResearchTriangle Park, North Carolina, USA. [73 T]

Author: U.S. Environmental Protection Agency (AP-42, Vol II)Year: 1985Title: Compilation of Air Pollutant Emission Factors. Volume II: Mobile SourcesPublisher: U.S. Government Printing Office, Washington, D.C., USAOther Info: Volume II of report # AP-42, 4th edition. Report is periodically updated; a 1991

Supplement is available.

Notes: "AP-42" is the USEPA's central compilation of air pollutant emission factors for virtually allsignificant sources of air pollution. Volume II of this series, together with its manysupplements, provides very detailed air pollutant emission factors for the types of gasoline- anddiesel-fueled vehicles and non-stationary equipment used in the United States. The volume isdivided into sections on "Highway Mobile Sources" (cars, trucks, buses, motorcycles) and "Off-Highway Sources" (aircraft, locomotives, watercraft, utility engines, agricultural and heavyequipment, and snowmobiles). Emission factors for carbon monoxide, nitrogen oxides, and non-methane hydrocarbons are presented for all sources, and additional emission factors are presentedfor some sources. A wealth of information is provided that allows emission factors to beadjusted for altitude, the age of the vehicle, temperature, and other parameters. Much of theemission factor information in EDB covering motor vehicles is derived from data in thiscompilation. The reader should be warned, however, that much of the information in thisreference is very technical, and may require some interpretation in order to be used directly withEDB and LEAP. The data in this volume is available in a software tool called MOBILE (thelatest version is MOBILE5), which allows the calculation of fleet-average emission factors for astock of automobiles described by the user. [420 M]

Author: U.S. Environmental Protection Agency (Radian-VOCs)Year: 1988Title: Air Emissions Species Manual. Volume I. Volatile Organic Compounds Species ProfilesPublisher: National Technical Information Service (NTIS), Springfield, VA, USA

157

Other Info: Prepared by Radian Corp. Report # EPA-450/2-88-003a

Notes: Provides information allowing estimation of atmospheric emission factors for particular organicspecies (e.g. benzene or methane) based on overall VOC emissions for a particular source,.Speciation profiles (or surrogate profiles) are available for most of the sources of emissionsdescribed in the USEPA's "AP-42" series. In many cases, profiles that have been measured forone source are used as default or surrogate values for similar types of equipment. This databaseis available in electronic format as part of the "AIR CHIEF" CD-ROM (optical data storage) diskdistributed by the EPA, and also as a part of the "CHIEF" computer bulletin board system, run bythe EPA from its Research Triangle Park office. [7 M]

Author: U.S. Environmental Protection AgencyYear: 1988Title: Toxic Air Pollutant Emission FactorsPublisher: USEPAOther Info: ATEF, Report Number EPA-450/2-88-006a

Notes: Provides air pollutant emission factors for toxic substances emitted from a variety of sources,including fuel-combustion sources. [0 M]

Author: U.S. Environmental Protection Agency (ASF)Year: 1989Title: Atmospheric Stabilization Framework, Appendix APublisher: USEPA Office of Policy, Planning, and Evaluation, Washington, D.C., USAOther Info: D. Tirpak and D. Lashof, Editors; draft form as of 2/90

Notes: This Appendix contains information on models of greenhouse gas emissions and effects and onbackground data for ASF's global inventory of GHGs, as well as the emission factor data files forselected greenhouse gas emissions (carbon dioxide, carbon monoxide, nitrogen oxides, nitrousoxide, methane) from a wide variety of sources of GHGs. Also included are data on theeffectiveness of technologies for reducing GHG emissions. Most of the emissions data includedhere were derived from earlier versions of Radian, 1990, and from other USEPA documents.Some of the materials in this volume (including the emission factor data files) were subsequentlypublished as a "Technical Appendix" Volume to the USEPA study Policy Options for StabilizingGlobal Climate, USEPA Report Number 21P-2003.3, December, 1990. [488 A]


Author: U.S. Environmental Protection AgencyYear: 1989Title: Locating and Estimating Air Toxics Emissions from Municipal Waste CombustorsPublisher: USEPA, Research Triangle Park, NC, USAOther Info: Report Number EPA-450/2-89-006

Notes: This document provides 1) an overview of the municipal solid waste (MSW) combustionindustry, 2) emission factors for different types of (MSW combustion equipment, and a list of thecurrent and planned MSW combustion facilities in the United States. Emission factors are givenfor acid gasses (e.g. nitrogen and sulfur oxides, hydrochloric acid), organic compounds, and toxicmetals. A description of the emission control technologies applicable to MSW combustionfacilities is also provided. This document is available on the "AIR CHIEF" CD-ROM (opticaldata storage) disk distributed by the EPA, and also as a part of the "CHIEF" computer bulletinboard system, run by the EPA from its Research Triangle Park office. [0 M]

Author: U.S. Environmental Protection Agency (NEDS)Year: 1989Title: NEDS (National Emissions Data System) Source Classification Codes and Emission

Factor FilePublisher: USEPA Office of Air Quality Planning and Standards, Research Triangle Park, NC, USAOther Info: EPA dBASE III+ data files for criteria pollutants

Notes: This database was the foundation of the national air pollutant inventory done in 1989 and before.It consists of data for criteria air pollutants (CO, NOx,, VOCs, Particulates, SOx) with emissionfactors for lead sometimes listed as well. It is derived primarily from the USEPA "AP-42"compilation, and was used for many data values in EDB. The database is indexed by sourceclassification codes that pertain to the type of source equipment and the sector or sub-sector forwhich the emission factor is applicable. This database is now included in the "Airs FacilitySubsystem" database of emission factors (see below). [1034 M]

Author: U.S. Environmental Protection AgencyYear: 1990Title: AIRS Facility Subsystem Source Classification Codes and Emission Factor Listing for

Criteria Air PollutantsPublisher: US EPA, Research Triangle Park, North Carolina 27711Other Info: Report number EPA 450/4-90-003

Notes: This database is similar to and updates the NEDS database of emission factors described above.Like NEDS, it primarily contains emission factor data for criteria air pollutants (CO, NOx,,VOCs, Particulates, SOx), and is derived primarily from AP-42 data. The database is indexedby source classification codes that pertain to the type of source equipment and the sector or sub-sector for which the emission factor is applicable. [3 M]

Author: U.S. Environmental Protection AgencyYear: 1993Title: Factor Information Retrieval (FIRE) SystemPublisher: US EPA, Research Triangle Park, North Carolina 27711Other Info: Prepared for the EPA by the Radian Corporation under EPA contract number: 68-D2-0160.

159

Notes: FIRE is an easy to use pc program containing EPA's recommended criteria and hazardous airpollutant emission estimation factors. FIRE contains information about industries and theiremitting processes, the chemicals emitted and emission factors themselves. It contains data onthe CAA criteria pollutants, 41 of the 189 HAPs specified in the CAAA, and 43 toxic airpollutants. The main sources of data used in FIRE include: (1) SPECIATE -- data from the AirEmission Species Database, which provides speciation factors for VOC and PM; (2) XATEF --data from the Crosswalk/Air Toxic Emission Factor (XATEF) database; (3) CARB -- data fromvarious report published by the California Air Resources Board (CARB) air regulatory initiative;(4) AFSEF -- data from the Aerometric Information Retrieval System (AIRS) Facility Subsystem(ASF) Emission Factor database; and (5) AP-42 -- data from the EPA's Compilation of AirPollutant Emission Factors, 4th ed., September 1985, including supplements A-F. [0 B]

Author: U.S. Environmental Protection AgencyYear: 1993Title: Air CHIEF (Clearinghouse for Inventories and Emission Factors) CD-ROMPublisher: US EPA, Research Triangle Park, North Carolina 27711Other Info: Prepared for the EPA by the Radian Corporation under EPA contract number: 68-D2-0160.

Notes: The Air Chief CD-ROM includes the EPA's Air CHIEF data base, the FIRE database, and anumber of WordPerfect and/or text formatted EPA documents (L&E's, AP-42 vol. 1, and variousbackground documents.) The Air CHIEF data base contains 26 EPA reports and 5 additionaldatasets that can be used to assist in finding and estimating pollutant emissions. [0 B]

Author: UNEPYear: 1985Title: Energy Supply/ Demand in Rural Areas in Developing CountriesPublisher: United Nations Environment Programme (UNEP), Nairobi, Kenya - Energy Report SeriesOther Info: Energy Report Series, ERS-11-84, Report of the Executive Director

Notes: [8 A]


Author: UNEP (Fossil Fuels)Year: 1979Title: The Environmental Impacts of Production and Use of Energy, Part I: Fossil FuelsPublisher: United Nations Environment Programme (UNEP), Nairobi, Kenya.Other Info: ERS-14-85, Part IV Comparative Assessment of the Environmental Impacts of Energy

Sources

Notes: Provides a primarily qualitative overview of the environmental impacts of the production and useof fossil fuels. Some generic quantitative emission and impact figures, including air emission,health and safety impacts, and solid wastes, are included as well. [30 M]

Author: UNEP (Nuclear)Year: 1979Title: The Environmental Impacts of Production and Use of Energy, Part II: Nuclear EnergyPublisher: United Nations Environment Programme (UNEP) - Energy Report Series, Nairobi, KenyaOther Info: Energy Report Series, ERS-2-79, Report of the Executive Director

Notes: As with the volume on fossil fuels above, this document provides a primarily qualitative overviewof the environmental impacts of the production and use of nuclear energy. Some genericquantitative data on emission from and impacts of the nuclear fuel cycle are provided as well.

[0 M]

Author: UNEP / von Gehlen, K. (Oil Shale)Year: 1985Title: The Environmental Impacts of Exploitation of Oil Shales and Tar SandsPublisher: UNEP - Energy Report Series / University of Frankfurt, GermanyOther Info: Energy Report Series, ERS-13-85, Prof. K. von Gehlen, Inst. of

Geochemistry/Petroleum/Economic Geology, University of Frankfurt/Main., GermanyNotes: [3 A]

Author: UNEP and Technical Research Centre of FinlandYear: 1985Title: The Environmental Impacts of Production and Use of Energy Part IV, Phase II

Comparative Assessment of the Environmental Impacts of Energy SourcesPublisher: UNEP and Technical Research Centre of FinlandOther Info:Notes: [0 M]

Author: Walsh, M., OECD, Air Policy Management GroupYear: 1988Title: The Motor Vehicles Project: Long Term Emissions from Motor VehiclesPublisher: Organization for Economic Co-operation and Development (OECD) Environmental

Directorate, Paris, France.Other Info: Report Number ENV/AIR/88.13 [0 M]

Author: World Health OrganizationYear: 1982

161

Title: Rapid Assessment of Sources of Air, Water, and Land PollutionPublisher: World Health Organization, Geneva, SwitzerlandOther Info: WHO Offset Publication No. 62

Notes: This document provides a comprehensive overview of the sources of air, water, and landpollution, including those in the energy sector. It also provides a good deal of quantitativeemissions and impacts data, though most is at a fairly generic level. This source is recommendedas a good general international reference for energy/environment planning. [67 M]

Author: World Health OrganizationYear: 1989Title: Management and Control of the EnvironmentPublisher: World Health Organization, Geneva, SwitzerlandOther Info: Report Number WHO/PEP/89.1

Notes: This is an update to the above document. [8 A]

Author: Yasukawa et. al.Year: 1990Title: Preliminary Analysis of Greenhouse Gas EmissionsPublisher: Japan Atomic Energy Research InstituteOther Info: This refers to a photocopied paper or part of a paper received by Tellus; it may have been

updated since.

Notes: This paper provides preliminary greenhouse gas emission factors for several sectors, as well astotal emissions estimates for those sectors in Japan. [0 M]

Authors: Zurlinden R.A, Von Dem Fange H.P, Hahn P.E, Ogden Projects IncorporatedYear: 1986Title: Environmental test report for Marion County Solid Waste to Energy FacilityPublisher: Ogden Martin Systems of Marion, Inc, Marion, IL, USA.Other Info: Tests were run to check compliance with permit conditions

Notes: Provides emissions test data for a US Municipal Solid Waste Combustion/Electricity Generationplant. [0 M]

163

APPENDIX B:

SUMMARY OF TABLE OF CONTENTS FROM GUIDELINE ONAIR QUALITY MODELS (USEPA)

The text below was obtained from the USEPA "SCRAM" computer bulletin board system, and isprovided as an example listing of the type of information that is available to assist planners in selecting andapplying air quality models.

SUMMARY OF TABLE OF CONTENTS

1.0 INTRODUCTION2.0 OVERVIEW OF MODEL USE

2.1 Suitability of Models2.2 Classes of Models2.3 Levels of Sophistication of Models

3.0 RECOMMENDED AIR QUALITY MODELS3.1 Preferred Modeling Techniques3.2 Use of Alternative Models3.3 Availability of Supplementary Modeling Guidance

3.3.1 The Model Clearinghouse3.3.2 Regional Meteorologists Workshops

4.0 SIMPLE-TERRAIN STATIONARY-SOURCE MODELS5.0 MODEL USE IN COMPLEX TERRAIN6.0 MODELS FOR OZONE, CARBON MONOXIDE AND NITROGEN DIOXIDE7.0 OTHER MODEL REQUIREMENTS

• Fugitive Dust/Fugitive Emissions• Particulate Matter• Lead• Visibility• Good Engineering Practice Stack Height

EPA-450/2-78-027R

GUIDELINE ON AIR QUALITY MODELS(Appendix W of 40 CFR Part 51)

July 1986(REVISED SEPT 93)

U.S. ENVIRONMENTAL PROTECTION AGENCYOffice of Air and Radiation

Office of Air Quality Planning and StandardsResearch Triangle Park, North Carolina 27711


• Long Range Transport (i.e., beyond 50km)• Modeling Guidance for Other Governmental Programs• Air Pathway Analyses (Air Toxics and Hazardous Waste)

8.0 GENERAL MODELING CONSIDERATIONS• Design Concentrations• Critical Receptor Sites• Dispersion Coefficients• Stability Categories• Plume Rise• Chemical Transformation• Gravitational Settling and Deposition• Urban/Rural Classification• Fumigation• Stagnation• Calibration of Models

9.0 MODEL INPUT DATA10.0 ACCURACY AND UNCERTAINTY OF MODELS11.0 REGULATORY APPLICATION OF MODELS12.0 REFERENCES13.0 BIBLIOGRAPHY14.0 GLOSSARY OF TERMS

APPENDIX A: SUMMARIES OF PREFERRED AIR QUALITY MODELS• BUOYANT LINE AND POINT SOURCE DISPERSION MODEL (BLP)• CALINE• CLIMATOLOGICAL DISPERSION MODEL (CDM 2.0)• GAUSSIAN-PLUME MULTIPLE SOURCE AIR QUALITY LGORITHM (RAM)• INDUSTRIAL SOURCE COMPLEX MODEL (ISC2)• MULTIPLE POINT GAUSSIAN DISPERSION ALGORITHM ITH TERRAIN ADJUSTMENT

(MPTER)• SINGLE SOURCE(CRSTER)MODEL• URBAN AIRSHED MODEL (UAM)• OFFSHORE AND COASTAL DISPERSION MODEL (OCD)• EMISSIONS AND DISPERSION MODEL SYSTEM (EDMS)• COMPLEX TERRAIN DISPERSION MODEL PLUS ALGORITHMS FOR UNSTABLE

SITUATIONS (CTDMPLUS)

APPENDIX B: SUMMARIES OF ALTERNATIVE AIR QUALITY MODELS• AIR QUALITY DISPLAY MODEL (AQDM)• AIR RESOURCES REGIONAL POLLUTION ASSESSMENT (ARRPA) MODEL• APRAC-3• COMPTER• ERT VISIBILITY MODEL• HIWAY-2• INTEGRATED MODEL FOR PLUMES AND ATMOSPHERIC CHEMISTRY• IN COMPLEX TERRAIN (IMPACT)• LONGZ• MARYLAND POWER PLANT SITING PROGRAM (PPSP)MODEL

165

• MESOSCALE PUFF MODEL (MESOPUFF II• MESOSCALE TRANSPORT DIFFUSION AND DEPOSITION MODEL FOR INDUSTRIAL

SOURCES (MTDDIS)• MODELS 3141 AND 4141• MULTIMAX• MULTI-SOURCE (SCSTER) MODEL• PACIFIC GAS AND ELECTRIC PLUMES MODEL• PLMSTAR AIR QUALITY SIMULATION MODEL• PLUME VISIBILITY MODEL (PLUVUE II)• POINT, AREA, LINE SOURCE ALGORITHM (PAL-DS)• RANDOM WALK ADVECTION AND DISPERSION MODEL (RADM)• REACTIVE PLUME MODEL (RPM-II)• REGIONAL TRANSPORT MODEL (RTM-II• SHORTZ• SIMPLE LINE-SOURCE MODEL (GMLINE)• TEXAS CLIMATOLOGICAL MODEL (TCM-2)• TEXAS EPISODIC MODEL (TEM-8)• AVACTA II• SHORELINE DISPERSION MODEL (SDM)• WYNDvalley MODEL• DENSE GAS DISPERSION MODEL (DEGADIS)