quantification of nox emissions reductions for sip credits ...€¦ · in 2001, the texas state...

14
Quantification of NO x Emissions Reductions for SIP Credits from Energy Efficiency and Renewable Energy Projects in Texas Malcolm Verdict, Jeff Haberl, Charles Culp, Bahman Yazdani, Tom Fitzpatrick, Don Gilman, Mushtaq Ahmed, Betty Liu, Juan Carlos Baltazar, Shirley Muns, and Dan Turner, Energy Systems Laboratory, Texas A&M University ABSTRACT This paper provides a detailed discussion of the procedures that have been developed and used to calculate the electricity savings and resultant NO x reductions from energy efficiency and renewable energy projects in non-attainment and affected counties using the United States Environmental Protection Agency (US EPA) and Texas Commission on Environmental Quality (TCEQ) guidance and the US EPA’s eGrid national data base of power plant emissions. This new methodology provides, for the first time, full emissions offsets from energy efficiency and renewable energy programs using creditable engineering analysis and verifiable data to help demonstrate compliance with the Federal Clean Air Act. Since four large metropolitan areas in Texas have been designated by the United States Environmental Protection Agency as non- attainment areas because ozone levels exceed the National Ambient Air Quality Standard (NAAQS) maximum allowable limits, this work is significant because these areas face severe sanctions if attainment is not reached by 2009. Background In 1970, the Federal Clean Air Act directed the United States Environmental Protection Agency to establish the maximum allowable concentrations of pollutants that are known to endanger human health, harm the environment or cause property damage. In response to this act, the EPA established NAAQS, 1 which describe the allowable maximum limits of six primary air pollutants. 2 In Texas, the Texas Commission on Environmental Quality (TCEQ) has the responsibility of measuring and reporting these emissions, including ozone, to the EPA. Nationally, areas that exceed safe levels of ozone are closely monitored by the EPA. Ozone is a poison formed when oxides of nitrogen (NO x ), volatile organic compounds (VOCs), and oxygen (O 2 ) combine in the presence of strong sunlight. Hence, controlling NO x emissions is fast becoming a critical priority for many areas of the United States. Furthermore, the US EPA is very interested in developing procedures for calculating creditable NO x emissions reductions from energy efficiency/renewable (EE/RE) programs, since many of the traditional enforcement programs have reached either their effective limits or are becoming very expensive and politically unacceptable. 3 1 National Ambient Air Quality Standards (NAAQS). 2 These pollutants currently are: carbon monoxide (CO -- 9 ppm, 8 hour average.), lead (Pb -- 1.5 ppm, maximum quarterly average), oxides of nitrogen (NO2 -- 53 ppb annual average), Ozone (O3 -- 120 ppb, 1 hour average.), particulate matter (PM10-- 50 micrograms/m3 annual average), and sulfur dioxide (SO2 -- 30 ppb annual average). 3 In Texas, the US EPA relies primarily on mandatory measures to produce large changes in air pollution. These measures include limits on VOC emissions, and limits on NOx emissions from point sources (i.e., power plants), 8-299 © 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Upload: others

Post on 11-Sep-2020

0 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Quantification of NOx Emissions Reductions for SIP Credits from Energy Efficiency and Renewable Energy Projects in Texas

Malcolm Verdict, Jeff Haberl, Charles Culp, Bahman Yazdani, Tom Fitzpatrick, Don Gilman,

Mushtaq Ahmed, Betty Liu, Juan Carlos Baltazar, Shirley Muns, and Dan Turner, Energy Systems Laboratory, Texas A&M University

ABSTRACT

This paper provides a detailed discussion of the procedures that have been developed and used to calculate the electricity savings and resultant NOx reductions from energy efficiency and renewable energy projects in non-attainment and affected counties using the United States Environmental Protection Agency (US EPA) and Texas Commission on Environmental Quality (TCEQ) guidance and the US EPA’s eGrid national data base of power plant emissions. This new methodology provides, for the first time, full emissions offsets from energy efficiency and renewable energy programs using creditable engineering analysis and verifiable data to help demonstrate compliance with the Federal Clean Air Act. Since four large metropolitan areas in Texas have been designated by the United States Environmental Protection Agency as non-attainment areas because ozone levels exceed the National Ambient Air Quality Standard (NAAQS) maximum allowable limits, this work is significant because these areas face severe sanctions if attainment is not reached by 2009.

Background

In 1970, the Federal Clean Air Act directed the United States Environmental Protection Agency to establish the maximum allowable concentrations of pollutants that are known to endanger human health, harm the environment or cause property damage. In response to this act, the EPA established NAAQS,1 which describe the allowable maximum limits of six primary air pollutants.2 In Texas, the Texas Commission on Environmental Quality (TCEQ) has the responsibility of measuring and reporting these emissions, including ozone, to the EPA. Nationally, areas that exceed safe levels of ozone are closely monitored by the EPA. Ozone is a poison formed when oxides of nitrogen (NOx), volatile organic compounds (VOCs), and oxygen (O2) combine in the presence of strong sunlight. Hence, controlling NOx emissions is fast becoming a critical priority for many areas of the United States. Furthermore, the US EPA is very interested in developing procedures for calculating creditable NOx emissions reductions from energy efficiency/renewable (EE/RE) programs, since many of the traditional enforcement programs have reached either their effective limits or are becoming very expensive and politically unacceptable.3

1 National Ambient Air Quality Standards (NAAQS). 2 These pollutants currently are: carbon monoxide (CO -- 9 ppm, 8 hour average.), lead (Pb -- 1.5 ppm, maximum quarterly average), oxides of nitrogen (NO2 -- 53 ppb annual average), Ozone (O3 -- 120 ppb, 1 hour average.), particulate matter (PM10-- 50 micrograms/m3 annual average), and sulfur dioxide (SO2 -- 30 ppb annual average). 3 In Texas, the US EPA relies primarily on mandatory measures to produce large changes in air pollution. These measures include limits on VOC emissions, and limits on NOx emissions from point sources (i.e., power plants),

8-299© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 2: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging the reduction of emissions of NOx by sources that are currently not regulated by the state, including area sources (e.g., residential emissions), on-road mobile sources (e.g., all types of motor vehicles), and non-road mobile sources (e.g., aircraft, locomotives, etc.).4 An important part of this legislation is the evaluation of the State’s new energy efficiency programs, which includes reductions in energy use and demand that are associated with specific utility-based energy conservation measures, renewable energy programs, and mandatory implementation of the International Energy Conservation Code5 (IECC 2000; 2001). In 2001, 38 counties in Texas were designated by the EPA as either non-attainment or affected areas. In 2003, three additional counties were classified as affected counties, bringing the total to 41 counties (16 non-attainment and 25 affected counties). Figure 1 shows the location of these counties in the state, with the largest concentration of counties in the three metro areas of Dallas-Ft. Worth in the northeastern portion of the state, the Houston-Galveston-Beaumont-Port Arthur area in the southeast corner along the Gulf coast, and the Austin-San Antonio area in central Texas.6 This paper provides a detailed discussion of the procedures that have been used to calculate the weather-normalized electricity savings and NOx reductions from more efficient residential and commercial construction in non-attainment and affected counties, energy efficiency projects from utility programs, and emissions reductions from green power purchases. Significance of the Work

Federal, state, and local governments are interested in quantifying the air quality benefits of EE/RE policies, programs and projects. Unfortunately, there is a considerable gap in available tools to assist federal and state agencies in estimating the environmental benefits of energy efficiency and renewable energy applications. In the US, methodologies are largely developed on a case-by-case basis for different purposes, and often contain poorly documented calculations and data sources, or are prohibitively expensive to apply to a state or region to achieve adequate rigor. Furthermore, the complexity of electricity production and inter-connection, and grid delivery are also a major barrier in estimating air emission reductions from electric sector EE/RE technologies.

In August 2004, the US EPA issued guidance on quantifying the air emission benefits from electric sector EE/RE projects. However, this was not a “cook book,” but rather it provided a flexible framework of requirements under which quantification methodologies could be designed so states could incorporate the reductions into their State Implementation Plans (SIPs) for achieving or maintaining the NAAQS. Only in Texas has a comprehensive engineering toolkit and database been developed that satisfies all aspects of the EPA’s 2004 guidance. The presence of this toolkit has also provided Texas with the ability to evaluate EE/RE technologies,

reductions in NOx emissions from mobile sources (automobiles and trucks), and mandatory NOx emissions levels for new large boilers, furnaces, etc. 4 In 2003, the 78th Legislature modified the Texas Emissions Reduction Plan (TERP) with House bill 3235 and House bill 1365. This new legislation strengthened the previous legislation, but did not reduce the stringency of the building code or the reporting of the emissions reduction. In the 2005 79th Legislature, the TERP was further modified to include the development of creditable emissions calculations from wind and renewables, and to investigate emissions reduction from area sources such as natural gas-fired, domestic water heaters. 5 The code adopted by the State of Texas is the 2000 IECC (IECC 2000), as modified by the 2001 Supplement (IECC 2001). 6 The El Paso area was designated a non-attainment area due high particulate concentrations.

8-300© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 3: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

which differ from traditional control techniques that are expensive and have no “payback” to the customer like EE/RE technologies. The success of this effort has also attracted the attention of the US EPA who is considering the application of the procedures developed in Texas for potential use by other states.

Figure 1. EPA Non-Attainment (Blue) and Affected Counties (Light Blue)

Quantification Methodology

The TCEQ is currently working with the EPA, through the Texas Emissions Reduction Plan (TERP), to determine how State Implementation Plan emissions reduction credits can be obtained from the reductions in electricity use from energy efficiency and renewable energy projects, with an emphasis on peak summertime electric demand,7 that are attributable to the adoption of the International Energy Conservation Code (IECC 2000) in non-attainment and affected counties. In order for the TCEQ to accomplish this, county-wide reductions in electricity use must be calculated by the Energy Systems Laboratory (ESL) and presented to the TCEQ in a suitable format for calculating emissions reductions using the EPA’s Emissions and Generation Resource Integrated Database (eGRID).8 This methodology is composed of several procedures 7 Currently, the peak day is the Ozone Season Day (OSD), which is the average daily use during a period from July 15 to Sept. 15 of the base year. For the current analysis this base year is 1999. Future analysis will include 2000 and 2002 base years. 8 The use of the eGRID database, which includes a simplified utility grid model based on annual sales of electricity data, was proposed by the TCEQ for use in calculating the emissions reduction from energy efficiency and renewable energy projects in 2001. Although more sophisticated electricity dispatch models provide higher accuracy, eGRID is acceptable to the EPA because it is based on public domain data and uses procedures that were developed and maintained for this purpose by the EPA. This database, eGRID, can be found at www.epa.gov/airmarkets/egrid/. The Texas eGRID database was specially compiled by Art Diem at the USEPA for the TCEQ.

8-301© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 4: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

that calculate and verify energy savings and emissions reductions from EE/RE projects using different sources of information, including:

1. The calculation of electricity and natural gas savings and peak-day electricity and natural

gas use reductions from the implementation of the IECC 2000 in new single-family and multi-family residences in non-attainment and affected counties as compared against 1999 single-family and multi-family housing characteristics using a code-traceable, calibrated DOE-2 simulation.

2. The calculation of electricity and natural gas savings and peak-day electricity and natural gas use reductions from the implementation of ASHRAE Standard 90.1-1999 in new commercial buildings in non-attainment and affected counties as compared against 1999 building characteristics using a code-traceable, calibrated DOE-2 simulation.

3. A cross-check of electricity and natural gas savings using a utility bill analysis method. 4. A cross-check of pre-code and post-code construction data using on-site visits.

In 2005, TCEQ expanded the TERP to include the development of integrated emissions reduction reporting across all state agencies participating in the TERP, which includes new code-compliant construction, utility programs, municipal projects, and green power purchases. Many of these procedures were also incorporated into a web-based EE/RE emissions calculator for use by planners. Additional detailed information about the methodologies described in this paper can be found in Haberl et al. (2002, 2003a, 2003b, 2004a, 2004b) and Im (2003).

Assembly of Measured Weather Data for 1999 through 2005

As a first step in the development of weather-normalized energy savings and peak demand reductions, measured weather data needed to be assembled for Texas as shown in Figure 2. To be consistent with long-term weather files, the emphasis was placed on those active stations nearest to the TMY2 stations as shown in Figure 2 (NREL 1995). Counties were then classified according to the nearest TMY2 station and corresponding IECC weather zone. Temperature, humidity, and wind measurements were obtained from NOAA (NOAA 1993). Solar data were assembled from the NREL measured solar data base, which was supplemented with TCEQ’s solar data base in those areas where the NREL solar data had been discontinued. Solar thermal and PV weather files used the weather designations provided by the F-CHART and PV F-CHART programs (Klein and Beckman 1983; 1985).

Determination of Code Compliant Residential Construction To calculate the energy savings and NOx emissions reductions from the implementation of the building codes in new construction, simulation models were created for single-family and multi-family residential buildings (Ahmed et al. 2005a; Malhotra 2005; Mukhopadhyay 2005). These simulation models were then modified to accommodate the different scenarios of construction and HVAC equipment typically used in the residential sector. The simulation models, created with the DOE-2.1e simulation program (LBNL 1993a; 1993b), were then linked to a web-based graphic user interface and the US EPA’s eGRID to automatically convert the energy savings to NOx emissions reduction.9 In Figure 3, an outline of the overall analysis is 9 This web-based calculator can be viewed at “ecalc.tamu.edu”.

8-302© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 5: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

provided. In this analysis, prototypical buildings were created. For each building type, simulations were performed for code and pre-code conditions using measured weather data assigned to each location. Savings were then multiplied by the number of new10 buildings in each county to yield the total county-wide savings. The electricity savings for each county were then converted to NOx reductions using eGRID.11 Natural gas savings were converted using the EPA’s conversion factors for the specific appliance/system.12 In the case of single-family residences, this included one-story, two-story, and slab-on-grade or crawlspace. Heating/cooling system types included electric resistance, heat pump or natural gas heating; electric or natural gas domestic water heating, and air-conditioning. The percentages of house/system types were determined by the National Association of Home Builders (NAHB) builder’s survey form (NAHB 2005).

Figure 2. Available Weather Data Sources and Climate Zones for Texas

El Paso

Midland

Amarillo

San Angelo

Wichita FallsAbilene

Fort Worth

Lufkin

Port Arthur

Houston

Corpus Christi

Victoria

San Antonio

Austin

Brownsville

9

87

6

5

4

3

2

LubbockWaco

DFW

SPS

FTW

BRO

LBX

ABI

ALI

GKYDAL

RBD

ATTAUS

AFW

BGD

11R

BWD

BMQ

CDS

CLL

CXO

CRP NGP

CRS

COT

DHT

DRT

DTO

6R6

ELP

BKS

FST

AMA

T82

GLE

GLS

GTU

HRL

HDO

IAH

LVJ

HOU

SGR

DWH

UTS

JAS

JCT

ERV

ILE

NQI

3T5

GGG

LBB

LFK

MRF

MFE

TKI

MAF

MWL

OSA

OCH

BAZ

ODO

PSX

PRX

PYX

BPT

PIL

RKP

GDP

SJT

SAT

SSF

HYI

SWW

TPL

TYR

VCT

PWG

ACT

T65

INK

TRL

TMY2 (17)

WYEC2 (4)

NWS (82)

NREL SOLAR (15)

F-CHART & PV FCHART (18)

TCEQ Solar (10)

55

2

ASHRAE 90.1 1989 City with Climatic Data

ASHRAE 90.1 1999 City with Climatic Data

In multi-family housing, the building types include 1 to 3 story units, which contain 2 to 12 residential units. In a similar fashion as single-family residential, heating/cooling system types included electric resistance, heat pump or natural gas heating; electric or natural gas domestic water heating, and air-conditioning. The percentages of house/system types were also determined by the NAHB builder’s survey form.

10 The number of new residences in each county was determined from the Real Estate Center (RECenter 2005), and consisted of 1-story or 2-story, slab-on-grade, or crawlspace statistical distributions. 11 This used a specially-created version of eGRID for all utilities in ERCOT projected to the year 2007, which was created by Art Diem at the USEPA for the TCEQ. eGRID can be found at www.epa.gov/airmarkets/egrid/. 12 EPA AP42 Project, 2003, www.epa.gov/ttn/chief/ap42/ap42supp.html.

8-303© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 6: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Figure 3. Overall Analysis Method for Calculating Energy and Emissions Savings from Energy Efficiency/Renewable Energy Projects

ESL Code TraceableDOE-2 Simulation

(Residential, Commercial, Industrial, Renewables)

County-wide Electricity Use(w/ and w/o code)

E-GRID Database Model For ERCOT, SERC,

SPP, and WSCC Regions

1999 BuildingCharacteristics

2000 IECC/IRCBuilding

Characteristics

Keep going…??Keep going…??Electric Power At Power Plants

NOAA WeatherData files for

Texas

Annual County-wide NOxemissions reductions (lb/yr,ton/day)

Number of BuildingsPer County

E-GRID Database of NOx, VOCsEmissions from Power Plants

In commercial buildings, the procedure used is shown in Figure 4. In this procedure it

was assumed that buildings built prior to September 200113 were built to be compliant with ASHRAE Standard 90.1-1989. After September 2001, buildings were assumed to be compliant with ASHRAE Standard 90.1-1999. New construction for commercial buildings was determined by merging information from three data sources. First, new construction activity by county was obtained from the Dodge MarkeTrack database (Dodge 2005), which provides the square footage of 12 building types by county. Energy savings from the adoption of ASHRAE Standard 90.1-1999 over 90.1-1989 was determined from the USDOE’s 2004 report on ASHRAE Standard 90.1-1999 (USDOE 2004), which included 7 building types. Next, as shown in Figure 4, the 12 Dodge building types were merged into the 7 USDOE building types, using information from CBECS (1995) to provide the annual energy savings by building type for each county. Then, using a DOE-2 code-compliant simulation for an office/retail building, annual/OSD ratios were created for the electricity and natural gas savings (Ahmed 2005b). The electricity savings for each county were then converted to NOx reductions using eGRID. Natural gas savings were converted using the EPA’s conversion factors for the specific appliance/system. Using these procedures, the estimated electricity savings for code-compliant residential and commercial construction14 in 2005 were determined to be 347,938 MWh/year, which included single-family (SF) savings of 263,656 MWh/year (180 tons-NOx/year), multi-family (MF) savings of 9,210 MWh/year (6 tons-NOx/year), and commercial (CO) savings of 75,072 MWh/year (49 tons-NOx/year). Natural gas savings (SF, MF and CO) were 699,737 MBtu/year (32 tons-NOx/year). Total NOx emissions reductions (electricity and natural gas) were 267 tons-NOx/year. On an ozone season day (OSD) the 2005 estimated electricity savings for code-compliant residential and commercial construction were determined to be 1,795 MWh/OSD, which included single-family (SF) savings of 1,298 MWh/OSD (0.88 tons-NOx/OSD), multi-family

13 September 2001 is the date that the 2001 Senate Bill 5 Legislation mandated code compliance. This assumption is based, in part, on the results of a survey conducted in 2004 of architects and engineers who design commercial buildings in Texas. 14 In 2005, it is estimated that there were 128,804 single family residences; 29,972 multifamily residences, which totaled about 350 million ft2; and 122 million ft2 of commercial building construction. Additional details can be found in the Laboratory’s 2005 report to the TCEQ (Haberl et al. 2006).

8-304© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 7: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

(MF) savings of 39 MWh/OSD (0.03 tons-NOx/OSD), and commercial (CO) savings of 457 MWh/OSD (0.29 tons-NOx/OSD). Natural gas savings (SF, MF and CO) were 1,209 MBtu/OSD (0.06 tons-NOx/OSD). Total NOx emissions reductions (electricity and natural gas) were 1.26 tons-NOx/OSD). Figure 5 shows the geographical distribution of the OSD electricity savings which corresponds to the most populated areas of the state (i.e., Harris, Tarrant, Collin and Dallas counties). Figure 6 shows the geographical distribution of the corresponding NOx reductions calculated by eGRID for the electricity generation facilities expected to be in the state in 2007. Comparison of the location of the electricity savings (Figure 5) to the location of the pollution savings (Figure 6) emphasizes the importance of the use of county-wide NOx distributions available in eGRID.15

Figure 4. Analysis Method for Calculating Energy and Emissions Savings from Commercial Buildings

Building construction (ft2/yr)according to 12 building types and 41 counties

Energy use (kBtu/ft2yr)according to 7 building types using

ASHRAE 90.1-1989 and 1999

DODGE PNNL

Amusement, Social and RecreationalBldgs / Religious Buildings

Manufacturing Plants, Warehouses,Labs / Warehouses (excl.

manufacturer owned)

Government Service Buildings /Miscellaneous Nonresidential

Buildings/Office and BankBuildings

Dormitories / Hospitals and OtherHealth Treatment / Hotels and Motels

Stores and Restaurants

Schools, Libraries, and Labs

Assembly

Education

Office

Lodging

Food

Retail

Warehouse

21.06% of food78.94% of retail fromCBEC (1999, 2003)

Calculate annual energy consumption of 7 building types using 1989 and 1999PNNL simulation results and ft2 from DODGE- Electric: kWh/ft2-yr * ft2

- Gas: mBtu/ft2-yr * ft2

Classify building types

DODGE building type PNNL building type

ft2 of 1999, 2000, 2001, 2002, 2003for each bldg types

Calculate annual energy savings of 7 building types- Electric consumption using ASHRAE90.1 1999 - Electric consumption usingASHRAE90.1 1989- Gas consumption using ASHRAE90.1 1999 - Gas consumption usingASHRAE90.1 1989

Complete DODGE datafrom 1999 to 2003 ?

No

Energy savings

20002001

20022003

Yes

Assume 2004 and 2005 annual energy savingsare equal to 2003 annual energy savings

2005

Energy savings

PNNL results using ASHRAE 90.1-1989

Electric (kWh/ft2-yr) Gas (mBtu/ft2-yr)Assembly 17.87 0.0322Education 10.35 0.0189Food 29.50 0.0355Lodging 12.43 0.0176Office 14.47 0.0056Retail 16.59 0.0040Warehouse 3.03 0.0082

PNNL results using ASHRAE 90.1-1999

Electric (kWh/ft2-yr) Gas (mBtu/ft2-yr)Assembly 16.18 0.0339Education 9.17 0.0201Food 29.84 0.0349Lodging 11.92 0.0159Office 12.94 0.0063Retail 13.98 0.0052Warehouse 5.20 0.0091

Calculate Ozone Season Day (OSD) energy consumptionUse eCalc to estimate OSD % using 1 office building- Annual electricity energy consumption * OSD %- Annual gas consumption * OSD %

1989 1999 1989 1999TOTAL (YEAR)(a) 988405 858198 331600000 278800000OSD (07/15 - 09/15) 199537 163841 30633205 10332355OSD PER DAY(b) 3167 2601 486241 164006OSD % (b/a) 0.32% 0.30% 0.15% 0.06%

Electricity (kW) Gas (Btu)

Calculate Ozone Season Day (OSD) energy savings- Electric savings in 1999 - Electric savings in 1989- Gas savings in 1999 - Gas savings in 1989

19992004

Note: Building size is 144 ft * 144 ft, 6-story office building using eCalc

15 In Figure 5, the bar graph shown compares with the left portion of the bar graph in Figure 6. The right side of eh bar graph in Figure 6 represents counties where the pollution is saved in counties outside the metropolitan area. In most instances, these represent rural counties where large power plants are located.

8-305© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 8: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Figure 5. 2005 OSD Electricity Reductions from IECC / IRC by PCA for Single-Family, Multi-Family Residences, and Commercial Buildings by County

OSD Elec. Savings w/ 7% T&D Loss(SF, MF Houses and Commercial Buildings)

-50

0

50

100

150

200

250

300

350

Har

risTa

rran

tC

ollin

Dal

las

Bexa

rTr

avis

Den

ton

Willi

amso

nEl

Pas

oM

ontg

ome

Gal

vest

onBr

azor

iaC

omal

Roc

kwal

lH

ays

Nue

ces

Fort

Ben

dE

llisJo

hnso

nG

uada

lupe

Kau

fman

Jeffe

rson

Par

ker

Sm

ithBa

stro

pC

ham

bers

Gre

gg San

Libe

rtyV

icto

riaO

rang

eC

aldw

ell

Wils

onH

ardi

nH

arris

onW

alle

rU

pshu

rR

usk

Hoo

dH

unt

Hen

ders

on

County

OSD

Ele

c. S

avin

gs (M

Wh/

yr)

Single Family Houses Multifamily Houses Commercial Buildings

Determination of Integrated NOx Emissions across State Agencies

In 2005, the TCEQ initiated a program to develop estimates of cumulative NOx emissions

reduction across all the Texas state agencies participating in the EE/RE programs of the TERP for purposes of consideration in the SIP. To accomplish this, uniform accounting procedures

8-306© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 9: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

needed to be applied to the reported energy savings that incorporated the EPA required degradation, discount, growth, and T&D losses.16, 17 Figure 7 provides a flowchart of the overall process that was established for reporting energy savings and the conversion of savings into creditable annual and OSD NOx values. For each agency, this required reporting the energy savings by county or utility provider. The 2007 eGRID values for annual and OSD were then applied for each utility to determine the NOx emissions reduction by county, by agency and total emissions reductions. Figure 8 provides a summary graph of the cumulative electricity and NOx emissions reductions for the OSD. In 2009, OSD savings are expected to be 15.42 tons-NOx/OSD, which represents 4.47 tons-NOx/OSD from new residential construction, 3.98 tons-NOx/OSD from PUC SB5 and SB7 programs,18 1.29 tons-NOx/OSD from SECO programs,19 and 5.69 tons-NOx/OSD from green power purchases20 (i.e., wind). Summary

This paper provides a discussion of the procedures that have been used to calculate the electricity savings and NOx reductions from new code-compliant residential and commercial construction in non-attainment and affected counties, energy efficiency projects from utility programs, and emissions reductions from green power purchases in Texas. These procedures include weather-normalization of energy savings to allow for the calculation of NOx emissions reductions during the base year and in future years using projections of new utility plants. This paper also discusses the efforts to develop integrated procedures across several state agencies that follow the US EPA’s Guidance document for NOx emissions reductions for State Implementation Plans for EE/RE programs.

In Texas, the promise of SIP credit for EE/RE projects has stimulated discussions among city planners and state officials about how to make buildings more efficient and how this efficiency can be translated in to creditable NOx emissions reductions – something that was only roughly estimated a few years ago. Also, the procedures discussed in this paper represent a first-of-a-kind effort by any state or national lab to develop creditable NOx emissions reductions from EE/RE projects. Previous efforts by other states have usually resulted in average emissions factors applied to statewide average assumptions. In Texas, emissions reductions been now been traced back to specific power plants, using county-level data from the EPA’s eGRID database. The new methodology provides, for the first time, county-wide emissions offsets for specific EE/RE measures to help the state demonstrate compliance with the Federal Clean Air Act. These 16 See the TCEQ Guide: Incorporating Energy Efficiency/Renewable Energy (EE/RE) Projects into the SIP: A Guide for Local Entities. (TCEQ 2004). 17 Values used for TCEQ cumulative, integrated emissions calculations include: 5% annual degradation factor (ESL, SECO, PUC, Wind), 7% T&D losses (ESL, PUC, SECO), 0% T&D losses (wind), 20% discount factor (ESL), 25% discount factor (PUC, Wind), 60% discount factor (SECO). Growth rates used were 3.25% (ESL-MF), 1.54% (ESL-SF), 0% (PUC, SECO), 17% (Wind, approx. 3,700 MW, installed by 2009). 18 The Public Utility Commission’s SB5 and SB7 load reduction programs included savings from AEP, Centerpoint, TXU, TNMP, Entergy and Xcel Energy. 19 In 2004 SECO reported energy savings from 154 municipal retrofit projects, which included primarily ESCO-funded projects. Some of the largest projects included the City of Dallas, the City of Ft. Worth, City of Gregg, City of Austin, City of Denton, City of Carrollton, and the City of Galveston. 20 The installed green power sites included over 32 wind farms located in the state. These find farms generated power that offset power sold by TXU (106 TWh/yr = 106,000,000 MWh), Reliant (104 TWh/yr), Entergy (33 GWh), AEP (33 GWh), San Antonio Public Service (15 TWh), El Paso Electric (3 TWh), LCRA (12 TWh), TNMP (10 TWh), and Austin Energy (4 TWh).

8-307© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 10: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

county-level emissions reductions allow air modelers to calculate emissions reductions by region, by utility provider, or for the whole state.

Figure 6. 2005 OSD NOx Reductions from Electricity and Natural Gas Savings Due to the

IECC / IRC for Single-Family, Multi-Family Residences, and Commercial Buildings by County (Using 2007 eGRID)

OSD NOx Emissions Reductions

(SF, MF Houses and Commercial Buildings)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Har

risTa

rrant

Col

linD

alla

sB

exar

Trav

isD

ento

nW

illia

mso

nE

l Pas

oM

ontg

omer

Gal

vest

onB

razo

riaC

omal

Roc

kwal

lH

ays

Nue

ces

Fort

Ben

dEl

lisJo

hnso

nG

uada

lupe

Kau

fman

Jeffe

rson

Park

erS

mith

Bas

trop

Cha

mbe

rsG

regg

San

Libe

rtyVi

ctor

iaO

rang

eC

aldw

ell

Wils

onH

ardi

nH

arris

onW

alle

rU

pshu

rR

usk

Hoo

dH

unt

Hen

ders

onW

ard

McL

enna

nM

itche

llFr

eest

one

Fann

inY

oung

Che

roke

eTi

tus

Lim

esto

neR

ed R

iver

Rob

erts

onP

alo

Pin

toLl

ano

Has

kell

How

ard

Cal

houn

Lam

arN

olan

Hid

algo

Cam

eron Frio

Bra

zos

Jone

sW

ilbar

ger

Faye

tteA

ngel

ina

Whi

chita

Wha

rton

Web

bC

oke

Grim

esA

ndre

ws

Col

eman

Har

dem

anP

ecos

Upt

onTa

ylor

Tom

Gre

enW

ise

Pre

sidi

oB

osqu

eC

rock

ett

Ecto

rJa

ckM

ilam

County

OSD

NO

x Em

issi

ons

Red

uctio

ns (T

ons/

day)

Single Family Houses Multifamily Houses Commercial Buildings Natural Gas

Non-attainment and Affected Counties Other Counties

8-308© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 11: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Figure 7. Process Flow Diagram of the NOx Emissions Reduction Calculations

ESL-single family (MWh/county)

ESL-multifamily (MWh/county)

PUC-SB7 (MWh/PCA)

PUC-SB5 (MWh/PCA)

SECO (MWh/PCA)

Wind-ERCOT (MWh/PCA)

Energy Savings Summary

2007 Annual eGrid (25%)

2007 OSD eGrid (25%)

NOx emissions reduction by

program

NOx emissions reduction by SIP

area

NOx emissions reduction by

county

NOx emissions reduction by

program

NOx emissions reduction by SIP

area

NOx emissions reduction by

county

ESL-single family (MWh/county)

ESL-multifamily (MWh/county)

PUC-SB7 (MWh/PCA)

PUC-SB5 (MWh/PCA)

SECO (MWh/PCA)

Wind-ERCOT (MWh/PCA)

Energy Savings Summary

2007 Annual eGrid (25%)

2007 OSD eGrid (25%)

NOx emissions reduction by

program

NOx emissions reduction by SIP

area

NOx emissions reduction by

county

NOx emissions reduction by

program

NOx emissions reduction by SIP

area

NOx emissions reduction by

county

Figure 8. Integrated Electricity and NOx Emissions Reductions 2004 through 2013 OSD Electricity Savings

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

2004 Cumulat ive2005

Cumulat ive2006

Cumulat ive2007

Cumulat ive2008

Cumulat ive2009

Cumulat ive2010

Cumulat ive2011

Cumulat ive2012

Cumulat ive2013

MWH/O

zone

Sea

son Day

ESL-Single Family ESL-Multifamily PUC (SB7)

PUC (SB5 grant program) SECO Wind-ERCOT

OSD NOx reduction leve ls

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

2004 Cumulat ive2005

Cumulat ive2006

Cumulat ive2007

Cumulat ive2008

Cumulat ive2009

Cumulat ive2010

Cumulat ive2011

Cumulat ive2012

Cumulat ive2013

Tons

/Ozo

ne S

easo

n Day

ESL-Single Family ESL-Multifamily PUC (SB7)

PUC (SB5 grant program) SECO Wind-ERCOT

8-309© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 12: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Acknowledgements

Funding for this work is provided by the State of Texas, under Senate Bill 5, and the US EPA through the TCEQ. The authors would also like to acknowledge the significant contributions of Ms. Sherrie Hughes, Ms. Rebecca Brister, Ms. Shirley Muns, Mr. Larry Degelman, Mr. Piljae Im, Ms. Jaya Mukhopadhyay, Ms. Mini Malhotra, Mr. Seongchan Kim, and Ms. Chayapa Chongchareonsuk. Thanks also to the pioneering work of Mr. Steve Anderson and Mr. Alfred Reyes, senior staff at the TCEQ. References Ahmed, Mushtaq, Don Gilman, Jaya Mukhopadhyay, Mini Malhotra, Jeff Haberl, and Charles

Culp. 2005a. “Development of a Web-based Emissions Reduction Calculator for Code-compliant Single-family and Multi-family Construction.” In Proceedings of the 5th International Conference for Enhanced Building Operation, Pittsburgh, PA.

Ahmed, Mushtaq, Don Gilman, Seongchan Kim, Chayapa Choncharoenshk, Mini Malhotra, Jeff

Haberl, and Charles Culp. 2005b. “Development of a Web-based Emissions Reduction Calculator for Code-compliant Commercial Construction.” In Proceedings of the 5th International Conference for Enhanced Building Operation, Pittsburgh, PA.

American Society of Heating, Refrigerating, and Air-conditioning Engineers. 1989. Standard

90.1-1989-Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings. Atlanta, GA.

American Society of Heating, Refrigerating, and Air-conditioning Engineers. 1999. Standard

90.1-1999-Energy Standard for Buildings Except Low-Rise Residential Buildings. Atlanta, GA.

CBECS 1995. USDOE Commercial Building Energy Characteristics Survey. U.S.D.O.E. Energy

Information Agency Report. Dodge. 2005. MarkeTrack: McGraw-Hill Construction Analytics. McGraw-Hill Construction

Information Group, 148 Princeton-Hightstown Road., Hightstown, N.J. http://dodge.construction.com

EPA AP42 Project, 2003, for residential furnace (uncontrolled) - heat input <0.3 MMBtu/hr (All

emissions factors were updated based on 482 data points taken from 151 source tests in 1998), www.epa.gov/ttn/chief/ap42/ap42supp.html.

Haberl, Jeff, Charles Culp, Bahman Yazdani, Tom Fitzpatrick, and Dan Turner. 2002. “Texas

Senate Bill 5 Legislation for Reducing Pollution in Non-attainment and Affected Areas: Annual Report.” submitted to the Texas Natural Resources Conservation Commission, Energy Systems Laboratory, Report No. ESL-TR-02-07-01, Texas A&M University, 116 pages (Revised: September).

8-310© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 13: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Haberl, Jeff, Charles Culp, Bahman Yazdani, Tom Fitzpatrick, and Dan Turner 2003a,b. “Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reductions Plan (TERP).” Volume I – Summary Report (Report No. ESL-TR-03-12-04) and Volume II – Technical Report, Annual Report to the Texas Commission on Environmental Quality, September 2002 to August 2003, Energy Systems Laboratory, Report No. ESL-TR-03-12-04, 175 pages.

Haberl, Jeff, Charles Culp, Bahman Yazdani, Don Gilman, Tom Fitzpatrick, Shirley Muns,

Malcolm Verdict, Mushtaq Ahmed, Betty Liu, Juan Carlos Baltazar-Cervantes, John Bryant, Larry Degelman, and Dan Turner. 2004a,b,c. “Energy Efficiency/Renewable Energy Impact in the Texas Emissions Reductions Plan (TERP).” Volume I – Summary Report (Report No. ESL-TR-04-12-01), Volume II – Technical Report (Report No. ESL-TR-04-12-04), Volume III – Appendix, Annual Report to the Texas Commission on Environmental Quality, September 2003 to August 2004, Energy Systems Laboratory, Report No. ESL-TR-04-12-05, 217 pages.

Huang, Joe. 2002. DrawBDL, Ver. 2.02. Joe Huang and Associates, 6720 Potrero Ave., El

Cerrito, CA, 94530-2248. IECC 2000. International Energy Conservation Code. International Code Congress, Falls

Church, VA, Second printing, January 2001. IECC 2001. 2001 Supplement to the International Codes. International Code Congress, Falls

Church, VA, Second printing, March 2001. Im, Piljae. 2003. “A Methodology to Evaluate Energy Savings and NOx Emissions Reductions

from the 2000 International Energy Conservation Code (IECC) to New Residences in Non-attainment and Affected Counties in Texas.” Master’s Thesis, Department of Architecture, Texas A&M University, ESL Report No. ESL-TH-03-12-05.

Kissock, Kelly, Jeff Haberl, and David Claridge. 2003. “Inverse Model Toolkit (1050RP):

Numerical Algorithms for Best-Fit Variable-Base Degree-Day and Change-Point Models.” ASHRAE Transactions-Research, Vol. 109, Part 2, pp. 425-434.

Klein, Sanford A., and William A. Beckman. 1983. F-Chart Solar Energy System Analysis: DOS

Version 5.6. F-Chart Software, 4406 Fox Bluff Road, Middleton, WI, 53562, www.fchart.com.

Klein, Sanford A., and William A. Beckman. 1985. PV F-Chart User’s Manual: DOS Version

3.3. F-Chart Software, 4406 Fox Bluff Road, Middleton, WI, 53562, www.fchart.com. LBNL, 1993a. DOE-2.1e BDL Summary. Lawrence Berkeley National Laboratory LBNL Report

No. 349346. LBNL, 1993b. DOE-2.1e Supplement. Lawrence Berkeley National Laboratory LBNL Report

No. 349347.

8-311© 2006 ACEEE Summer Study on Energy Efficiency in Buildings

Page 14: Quantification of NOx Emissions Reductions for SIP Credits ...€¦ · In 2001, the Texas State Legislature formulated and passed Senate Bill 5 to further reduce ozone levels by encouraging

Malhotra, Mini. 2005. “An Analysis of Maximum Residential Energy-Efficiency in Hot and Humid Climates.” Master’s Thesis, Department of Architecture, Texas A&M University, ESL Report No. ESL-TH-05-12-01.

Mukhopadhyay, Jaya. 2005. “Analysis of Improved Fenestration for Code-Compliant Residential

Buildings in Hot and Humid Climates.” Master’s Thesis, Department of Architecture, Texas A&M University, ESL Report No. ESL-TH-05-08-01.

NAHB 2005. Home Builder’s Surveys. National Association of Home Builders, 1201 15th Street

NW, Washington, D.C., 20005. NOAA 1993. Automated Surface Observing System Guide for Pilots. National Oceanic and

Atmospheric Administration, U.S. Department of Commerce, National Weather Service (April).

RECenter 2005. Texas Real Estate Research Center, College of Business, Texas A&M

University, College Station, Texas. URL: recenter.tamu.edu. TCEQ. 2004. “Incorporating Energy Efficiency/Renewable Energy (EE/RE) Projects into the

SIP: A Guide for Local Entities.” Texas Commission on Environmental Quality, Austin, TX (February).

USDOE 2004. Building Energy Standards Program: Determination Regarding Energy

Efficiency Improvements in the Energy Standard for Buildings, Except Low-Rise Residential Buildings, ASHRAE/IESNA Standard 90.1-1999. Docket No. (Docket No. EE-DET-02-001). Washington, D.C. http://www.energycodes.gov/implement/pdfs/FR_com_notice.pdf

8-312© 2006 ACEEE Summer Study on Energy Efficiency in Buildings