Energy Resource and Consumption

10-15% of your APES Exam

Forms of EnergyType DescriptionMechanical There are two types of mechanical energy: Potential (book sitting on

a table) and Kinetic (book falling off of table)Thermal Heat is the internal energy in substances- the vibration and

movement of the atoms and molecules within a substanceChemical Chemical energy is stored in bonds between atoms in a moleculeElectrical Electrical energy results from the motion of electronsNuclear Nuclear energy is stored in the nuclei of atoms. It is released by

either splitting or joining atomsElectromagnetic Electromagnetic energy travels by waves

Units of Energy/PowerUnit/Prefix Description

Btu (British Thermal Unit)

Btu is a unit of energy also used in the US. In most countries it has been replaced with the joule. A Btu is the amount of heat required to raise the temperature of 1 pound of water by 1 F. 1 watt is about 3.4 Btu/hr. 12,000 Btu/hr is referred to as a “ton” in many air-conditioning applications

Horsepower Used in the auto industry. 1 horsepower (HP) is equal to 746 watts

Kilo- Means 1,000 or 103 . 1 KW = 103 watts

Mega- Means 1,000,000 or 106. 1 MW= 106 watts

Watt (electrical) A kilowatt-hour (kWh) is the amount of energy expended by a 1 kilowatt (1000 watt) device over the course of 1 hour. Often measured in the context of power plants and home energy bills

Watt (thermal) Nuclear power plants produce heat measured in thermal watts

You do not need to know the conversions, if there is a conversion, they will give it to you.Except for going from Kilo- to Mega- ect.

Laws of Thermodynamics

• First Law: Energy cant be created or destroyed• Second Law: When energy is converted from

one form to another, a less useful form results (energy quality). Energy cant be recycled to a higher quality. Only 20% of the energy in gasoline is converted to mechanical energy. The rest is lost as heat and is knoen as low-quality energy.

Energy Consumption

• Wood (a renewable energy) served as the predominate form of energy up until the industrial revolution

• During the Industrial Revolution, coal surpassed wood’s usage.

• Coal was overtaken by petroleum during the middle of the 20th century, with petroleum continuing to be the primary source of energy world wide

• Natural gas and coal experienced rapid development in the 2nd half of the 20th century.

Energy Consumption

• The US was self-sufficient in energy until the late 1950s.

• At that time energy consumption began to outpace domestic production which then lead to oil imports

• The industrial sector uses the most energy in the US, followed by transportation and commercial uses.

Present Global Energy UseCommodity US Production US Consumption

Oil 18% 39%

Natural Gas 27% 23%

Coal 33% 23%

Nuclear 10% 7%

Renewable 9% 3.6%

Hydroelectric 5% 4%

Present Global Energy UseUS Energy Production By Sector

Transportation 27%

Industrial 38%

Residential and commercial 36%

Commodity Consumption by the US % of total world Usage

Oil 40%

Natural Gas 23%

Coal 23%

Future Energy Needs

• Continued growth and reliance on: petroleum, natural gas and coal.

• The most realistic, economical and viable resources of future energy needs are clean coal, methane hydrates, oil shale and tar sands.

Clean Coal

• Reduces negative effects of burning coal • Process includes: washing coal to remove minerals and

impurities and capturing the SO2 and CO2 from flue gases. • Also focuses on natural gas or microbial fuel cells charged

with biomass or sewage. • Process: 1. oxygen is introduced to completely burn the

coal. 2. coal is pulverized in order to burn it more completely. Coal is also washed to remove contaminates. 3. Ash is removed using electrostatic precipitators. 4. Steam is condensed and returned to the boiler. 5. CO2 is recovered using lime and then sequestered.

Clean Coal Production

Methane Hydrates• Methane Hydrates (methane locked in ice) are a recently

discovered source of methane that form at low temps and high pressure. They are found in permafrost regions and beneath the ocean floor

• Some believe there is enough methane in the form of hydrates to supply energy for 100-1000 years

• Natural gas is expected to take on a greater role in power generation

• This is because of increasing pressure for clean fuels and relatively low capital costs.

• The US will consume increasing volumes of natural gas (increase of 40%)

• The primary waste product of burning natural gas is CO2

Oil Shale• Oil shale contain an organic material called Karogen• If oil shale is heated in the absence of air, it becomes

oil• There are about 3 trillion barrels of possible oil from

oil shale reserves in the World.• Can be extracted through surface mining or in situ

methods ( heating the oil shale under the ground and extracting the oil and gases through pumping)

• Most of the oil shale in the world are in Estonia, Australia, Germany, Israel and Jordan

• In the United States: Wyoming, Utah and Colorado

Tar Sands

• Tar Sands contain Bitumen- a semisolid form of oil that doesn’t flow.

• Specialized refineries are capable of converting bitumen to oil. • Mined using strip-mining • In Situ can also be used• Sulfur content is high • Deposits located in Canada and Venezuela. (Canada is the best

for mining- more concentrated)• The net-energy yield is moderate- energy required for extraction• Oil in Tar Sands represents about 2/3 of the worlds total oil

reserves.

Energy Crisis• In a free-market economy, the price of energy is driven by the

principle of supply and demand. • Sudden changes in the price of energy can occur if either

supply or demand changes. • In some cases, an energy crisis is brought on by a failure of

world markets to adjust to prices in response to shortages. • Most of the world’s energy is supplied by burning oil. • At current rate of consumption, world oil reserves are predicted

to last 50 years with oil reserves in the US lasting 25 years. • Industrialization of China would significantly decrease this

prediction• As supply decreases, prices will increase

OPEC

• Organization of Petroleum Exporting Countries• Ex: Saudi Arabia and Venezuela• When OPEC reduces the output quotas of its

member countries the price of oil increases as the supply diminishes

• OPEC can also boost oil production in order to increase supply which decreases price

• When OPEC raises the price of oil too high the demand decreases and production of oil from alternative sources becomes profitable.

CrisisYear Description

1973 Oil crisis. Export embargo by OPEC in response to western support of Israel

1979 Oil Crisis caused by Iranian Revolution1990 First Gulf War2000-2001

California electricity crisis. Deregulation of the industry and corporate corruption

2006 Oil price increases due to increases demand by India and China. Political instability in Iran, Iraq and Venezuela

Fossil Fuel Resource and Use- Coal• Coal is produced by decomposition of ancient organic matter

under high temp and pressure• Sulfur from the decomposition of Hydrogen Sulfide by anaerobic

bacteria became trapped in coal • Three types of coal: Lignite, bituminous and anthracite• Lignite or brown is the softest and has the lowest heat content• Bituminous is soft and has high sulfur content and is 50% of the

US reserve• Anthracite is hard and has a high heat content and low sulfur

content and makes up 2% of the US reserve• Peat is pre-coal and is used in some countries for heat but has a

low heat content.

Fossil Fuel Resource and Use- Coal

• Coal supplies 25% of the worlds energy with China and the US consuming the most.

• In the US 87% of the coal is used for power plants to produce electricity

• The Clean Air Act requires up to a 90% reduction in the release of Sulfur-containing gases

Fossil Fuel Resource and Use- Oil

• Fossil fuel produced by the decomposition of deeply buried organic material under high temps and pressures for millions of years

• Compounds derived from oil are known as petrochemicals

• They are used in the manufacture of paints, drugs, plastics and so on.

Fossil Fuel Resource and Use- Natural Gas

• Known as Methane or CH4

• Produced by the decomposition of ancient organic matter under high temps and pressure

• Conventional sources of methane are found associated with oil deposits

• Unconventional sources include coal beds, shale, gas hydrates and tight sands

• Methane can be liquefied which allows for worldwide distribution

Extraction-Purification Methods- Coal

• 2 primary methods of mining- Surface Mining and Underground Mining

• Coal that is going to be burned in solid form may go through a variety of preparation process

• These include removing foreign material, screening for size, crushing and washing to remove contaminants

• Its also possible to turn solid coal into a gas or liquid fuel through clean-coal technologies.

Extraction-Purification Methods-Oil

• Oil occurs un certain geologic formations at varying depths. • In many cases, elaborate, expensive equipment is required to extract it• Usually found in a layer of porous sandstone which lies just beneath a

dome-shaped of folded layer of nonporous rock like limestone• Oil can also be trapped at a fault or break in the layers of crust• Natural gas is usually present just below the nonporous layer

immediately above the oil• Below the oil layer the sandstone is usually saturated with salt water• Oil is releases when drilling a well and puncturing the limestone layer• The oil is usually under such great pressure that it flows naturally,

other times it has to be pumped• Once oil has been collected it is sent to a refinery where it is cracked• Cracking involves separating the components of oil by boiling points.

Refinery

Extraction-Purification Methods-Natural Gas

• Typically flows from wells under its own pressure

• It is collected by small pipelines that feed into a large gas transmission pipelines

• In the US about 20 trillion cubic feet of gas is produced each year.

Case Study- ANWR

• Artic National Wildlife Refuge• The largest national wildlife refuge in the US• Located in northeastern Alaska and consists of 19

million acres• The question of whether or not to drill for oil has been

a political controversy since 1977• Much debate over whether to drill in ANWR rests on

the amount of economically recoverable oil as it relates to the world market, weighed against the potential harm oil exploration might have on wildlife.

World Reserves and Global Demand

Coal Best estimates show that coal reserves are expected to last for about 300 years at current consumption. China has the largest reserves

Oil Of all known oil reserves, 65% is found in 1% of all fields- primarily in the Middle East

Natural Gas Russia and Kazakhstan have about 40% of the worlds reserves. The middle east has about 25% and the US has about 3%

Synfuels

• A liquid fuel synthesized from nonpetroleum sources such as coal, natural gas, oil shale or waste plastics. Shale oil is an example of a synfuel as it is derived from shale oil that is heated and the vapor condensed. Synthetic natural gas (SNG) is produced from coal liquefaction.

Pros ConsEasily Transported through pipelines Low net energy yield and requires energy to

produceProduces less air pollution Plants are expensive to buildLarge supply of raw materials available worldwide to meet current demands for hundreds of years

Would increase depletion of coal due to inherent inefficiencies

Can produce gasoline, diesel or kerosene directly without reforming or cracking.

Product is more expensive than petroleum products.

CoalPros Cons

Abundant, known world reserves will last about 300 years at current rates

Most extraction in the US is done through strip or underground mining. These methods cause disruption to the land through erosion, runoff and decrease in biodiversity

Unidentified world reserves are estimated to last 1000 years at current rates

Up to 20% of coal ends up as fly ash, boiler slag or sludge. Burning coal releases mercury, sulfur, and radioactive particles. 25% of all CO2 releases are from coal and 30% of all pollutants due to NOx

US reserves are estimates to last 300 years at current rates

Underground mining is unhealthy and dangerous

Relatively high net-energy yield Expensive to process and transport. Cant be used effectively for transportation needs

US gov subsidies keep prices low Pollution can cause global warming. Scrubbers and other antipollution control devices are expensive

Stable; nonexplosive, not harmful if spilled

Oil Pro Con

Inexpensive, however process are increasing making alternatives more attractive

World oil reserves are limited and declining

Easily transported through established pipelines and distribution networks

Produces pollution. Production releases contaminated wastewater and bring

High net-energy yield Causes land disturbances in drilling process, which accelerates erosion

Ample supply for immediate future Oil spills both on land and in the ocean from platforms and tankers

Large US gov subsidies in place Disruption to wildlife habitats (Arctic Wildlife Refuge)

Versatile- used to manufacture many products.

Supplies are politically volatile.

Natural GasPros Cons

Pipelines and distribution networks are in place. Easily processed and transported at LNG over rail or ship

H2S and SO2 are released during processing

Inexpensive but prices are increasing. Viewed by many as a transitional fossil fuel as the world switches to alternative sources

LNG processing is expensive and dangerous, as it results in lower net energy

World reserves estimated about 125 years at current rates

Leakage of CH4 has a greater impact on global warming than does CO2

High net energy yield Disruption to areas where it is collected

Produces less pollution than any other fossil fuel

Extraction releases contaminated wastewater and brine

Extraction is not as damaging to the environment as either coal or oil.

Land subsidence

Fuel Prices

Nuclear Energy

• During nuclear fission, an atom splits into two or more smaller nuclei along with by-product particles (neutrons, photons, gamma rays and beta and alpha particles)

• The reaction is exothermic.• If controlled, the heat that is produced is used to

produce steam that turns generators that then produce electricity.

• If the reaction is not controlled, a nuclear explosion can occur

Nuclear Fission

Nuclear Energy

• The amount of potential energy contained in nuclear fuel is 10 million X more than that of coal and petroleum.

• The downside is that nuclear wastes remain highly radioactive for thousands of years are hard to dispose of

• The most common nuclear fuels are U-235, U-238 and Pu-239

U-235

• U-235 differs from U-238 in its ability to produce a fission chain reaction.

• The minimum amount of U-235 required for a chain reaction is called the critical mass

• Loc concentrations of it can be used if the speed of the neutrons is slowed down through the use of a moderator.

• Less than 1% of all natural uranium on Earth is U-235• Nuclear weapons contain 85% or more of U-235• The half-life is 700 million years

U-238

• U-238 is the most common (99.3%) isotope of Uranium

• It has a half life of 4.5 billion years• When hit by a neutron it decays into Pu-239

which is used as fuel in fission reactions

Pu-239

• Half-life of 24,000 years. • Produced in breeder reactors from U-238• Plutonium fission provides about 1/3 of the total

energy produced in a typical nuclear power plant• Control rods in nuclear power plants need to be

changed frequently because of the build up of Pu-239 (that can be used in Nuclear weapons) and Pu-240 (a contaminate)

• International inspections of nuclear power plants regulate the amount of Pu-239 produced

Nuclear Energy Production• Began in the 1960s and rapidly increased until the 1980s• Reasons for the decline: overruns, higher than expected

operating costs, safety issues, disposal of nuclear wastes and the perception of it being a risky investment

• There is now a renewed interest in nuclear energy because of global warming and rising costs of fossil fuels

• As of 2005, nuclear power provided 6% of all power in the world. 15% of power in the US

• France and Japan account for 57% of the power generated• As of 2007, there were 439 nuclear power plants in 31 countries. • Globally in the 1980s one new reactor started up every 17 days

on average.

Nuclear Energy Production

• The US produces the most nuclear energy with nuclear power providing 19% of the electricity is consumes

• France produces the most electrical energy at 78% in 2006.For Against

Sustainable source that can reduce carbon emissions

Potentially dangerous and a declining energy source

Increases energy security by decreasing need for foreign oil

Storing radioactive wastes is risky and hard

Risks of storing wastes are small and can be reduced by technology and smaller reactors

Potential for contamination by accident or sabotage

Operational safety record is already good when compared to other major power plants.

Nuclear Reactor• The Core, contains up to 50,000 fuel rods. Each rod is stacked

with many fuel pellets, each pellet having an energy equivalent to 1 ton of coal, 17,000 cubic feet of Natural Gas or 149 gallons of oil.

• Uranium oxide is the Fuel, 97% use U-238 and 3% use U-235• Control Rods (usually made of boron) move in and out of the

core to absorb neutrons and slow down the reaction• A Neutron Moderator is a medium the reduced the velocity of

fast neutrons, there by turning them into thermal neutrons capable of sustaining a nuclear chain reaction. Moderators can be water, heavy water or graphite

• Coolant removes heat and produces steam to generate electricity.

Nuclear Reactor

Environmental Pros for Nuclear Energy

• No air pollutants if operating correctly• Releases about 1/6 of the CO2 as fossil fuel

plants, thus reducing global warming• Water pollution is low• Disruption of land is low to moderate

Environmental Cons of Nuclear Power

• Nuclear wastes take millions of years to degrade. Problem of where to store them and keeping them out of the hands of terrorists

• Nuclear power plants are licensed in the US by the Nuclear Regulatory Commission (NRC) for 40 years. After that, they can ask to renew their license or they can shut down the plant and decommission it. Decommissioning it means the land can be used for other things. Since is may cost 300 million or more to shut down and decommission a plant the NRC requires plant owners to set aside the money ahead of time

• Low net-energy yield– energy required for mining uranium, processing ore, building and operating the plant, dismantling plant and storing wastes

• Safety and malfunctioning concerns

Relevant Law

• Price-Anderson Nuclear Indemnity Act (1957)• Covers all nonmilitary nuclear facilities constructed

before 2026.• It indemnifies the nuclear industry against all

liability claims arising from nuclear accidents while ensuring compensation coverage for the general public through no-fault insurance

• The first 10 billion coming from the nuclear industry and anything above that coming from the US Government.

Safety Issues (radiation and human health)

• The US department of Energy (DOE) estimates that up to 50,000 radioactive contaminated sites within the US require cleanup with a projected cost of 1 trillion dollars. This situation is many times worse in former Soviet Union

• Estimated Health Risk per Year in the US: Coal Nuclear

Premature Death 65,000 6,000Genetic defects/damage

200,000 4,000

Case Study: Chernobyl, Ukraine (1986)

• Explosion in a nuclear power plant sent highly radioactive debris throughout northern Europe.

• Estimates run as high as 32,000 deaths and 62,000 square miles remain contaminated

• 500,000 people were exposed to dangerous levels of radiation. • WHO- Chernobyl will cause 50,000 new cases of thyroid cancer

among young people living in the areas. Incidence of thyroid cancer in children has increases tenfold in the Ukraine

• The cost estimates run as high as 400 billion• The cause was determined to be both design and human error.

Nuclear Fusion

• Occurs when extremely high temps are used to force nuclei of isotopes of light weight atoms to fuse together which causes large amounts of energy to be released

• Coal-fed electrical plant producing 1000 megawatts of electricity in one day produces 30,000 tons of CO2, 600 tons of SO2 and 80 tons of NO2.

• In contrast, a fusion plant producing the same amount of electricity would produce 4 pounds of harmless helium.

Hydroelectric Power

Hydroelectric Power

• Dams are built to trap water which in turn is then released and channeled through turbines that generate electricity

• Hydroelectric power supplies about 10% of the electricity in the US

• About 3% worldwide

Pros and ConsPros ConsDams control flooding Dams create large flooded area behind the dam

from which people are displaces. Water is slow moving so it can create pathogens

Low operating and maintenance costs

Dams destroy wildlife habits and keep fish from migrating

No polluting waste products Sedimentation requires dredging. Prevents sediments from reaching down stream to enrich farmland

Long life spans Expensive to buildModerate to high net-useful energy

Large-scale projects are subject to earthquakes

Areas of water recreation Water loss due to increases water surface area.

Flood ControlMethod Description

Channelization Straightening and deepen streams. Cons: removes bank vegetation and increases stream velocity which causes erosion; may cause increase downstream flooding and sedimentation which destroys habitat

Dams Store water in reservoirs. During period of excessive rainfall, dams can be overwhelmed and excess water needs to be releases

Identify and manage flood prone areas

By identifying flood prone areas, precautionary building practices such as flood-ways, building elevation and pumping stations can be adopted

Levees or Floodwalls

Levees are raided embankments to prevent a river from overflowing. Levees contain river and stream flows but increase velocity. Levees can break as then did during Hurricane Katrina in 2005

Preserve Wetlands This technique preserves natural flood plains and maintains biodiversity

Salmon• There are an estimated 74,993 dams in the US, blocking

600,000 miles of what used to be free-flowing rivers• Salmon are migratory fish that hatch in streams and

ricers then swing downstream to the ocean to live most of their lives

• They return to rivers from which they hatched to spawn• Damns now block almost every major river system in

the West destroying the ability of the fish to spawn• The Columbia River Basin is now damed up and leaves

less than 70 miles of free flowing ricer. This leads to at least 106 major US west coast salmon runs extinct and 25 more endangered.

Salmon

• Low water velocities in large reservoirs can also delay salmon migration and expose fish to higher water temps and disease

• Cutting trees in forests near rivers and streams increases silt clouds and reduces water quality

• Things that have been done to help: fish passage facilities and fish latters. Spillways and water releases, as well as collecting and shipping the juvenile fish.

Silting and Other ImpactsImpact Description

Disease Dam reservoirs in tropical areas, due to their slow movement are literally breeding grounds for mosquitoes, snails and flies– the vectors that carry malaria, schistosomiasis and river blindness

Displacement Flooded areas behind dams destroy rich croplands and displace people

Effects of watersheds

Downstream areas are deprived of nutrient-rich silt that would revitalize depleted soil profiles

Impact on Wildlife Migration and spawning cycles are disruptedSilting Occurs when silt that dissolved in the river water settles out

behind dams. Over time, the silt builds up and has to be removed by dredging

Water loss Large losses of freshwater occur through evaporation and seepage through porous rock beds.

Energy Conservation

• Energy Star is a joint program with the EPA and U.S. Dept of Energy.

• Designed to protect the environment through energy-efficient products and practices

• Programs coordinated through Energy Star saved enough energy in 2005 to avoid greenhouse gas emissions equivalent to 23 million cars and 12 billion dollars

CAFE Standards

• Corporate Average Fuel Economy• Transportation needs consume 2/3 of petroleum

consumption in the US• Imports of crude oil are expected to increase by 66% by

2020• CAFE standards are average fuel economies for

manufacture’s fleet of passenger cars or light trucks• Estimated savings of 55 billion gallons of fuel annually

and a reduction in CO2 emissions by 10%• CAFE standard is 27.5 miles per gallon for automobiles

Hybrid Electric Vehicles

• Produces almost no pollution but has limited range between charges.

Hybrid Electric Vehicles

Gasoline Hybrid Cars

• Gasoline-electric hybrids contain 5 important parts:

• Engine- smaller than gas only cars, and reduces emissions

• Fuel tank- or energy storage device. • Advanced Electronics- allow the electric motor

to act as a generator• The generator- • Batteries- store energy.

Parallel Hybrid Cars

• Has a fuel tank that supplies gasoline to the engine and a set of batteries that supplies power to the electric motor

• Both the engine and electric motor power the car at the same time

• In a series hybrid, the gasoline engine turns a generator which charges the batteries and/or powers an electric motor

• The gasoline engine never actually powers the vehicle.

Plug-In Hybrid Cars

• Hybrid cars with an added battery• Can be plugged into a 120-volt outlet an

charged• Run on the stored energy for a typical days

driving (about 60 miles) • When the charge is used up it switched to

gasoline

Mass Transit

• Includes: Bus, rail, subway, airline, and ferries• In the US private cars are preferred• Mass transit use rises as population density

rises (In Japan 47% of people use mass transit)• The most efficient method to promote mass

transit is to adopt a user-pays approach • Sometimes it is faster than driving your own

car

Mass TransitType Description

Light Rail Consists of trains that share space with road traffic and trains that have their own right of way and are separated from road traffic

Group or Personal Rapid Transit

Private vehicles similar to cars or buses that are able to travel under a drivers control but are then able to enter an automated guide way or track for extended distances. Could be powered by fuels when out of system and electricity when entering the system

Automated Highway Systems

Sensors in roadbed monitor an control traffic flow by adjusting vehicle speed and spacing to reduce congestion

Bus Rapid Transit

Included bus-dedicated ad grade-separated right of ways, bus lanes, bus signal preferences and preemption, bus turnouts, bus-boarding islands off-bus fare collection

Maglev Magnetically levitated trains that “float” above the rails to reduce friction

Tubular Tail Trains that don’t sit on tracks but rather travel through distantly spaced support structures.

RENEWABLE ENERGY

Solar Energy

• Consists of collecting and harnessing radiant energy from the sun to provide heat and/or electricity.

• Power can be generated at home and at industrial sites through photovoltaic cells, solar collectors or solar-thermal plants

• Active solar collectors use the suns energy to heat water or air inside a home or business. It requires electrical input from pumps or fans

• Passive solar doesn’t require moving parts• Photovoltaic cells are used to generate electricity

Solar EnergyPro Con

Supply of solar energy is limitless Inefficient where sunlight is limited or seasonal

Reduces reliance on foreign imports

Maintenance costs are high

Only pollution is in manufacturing of cells. Little environmental impact

Systems deteriorate and must be periodically replaced

Can store energy during the day and release it at night- good for remote locations

Current efficiency is between 10-25% and is not expected to increase soon

Hydrogen Fuel Cells

• 9 million tons of Hydrogen is produces in the US each day– enough to power 20-30 million cars and 5-8 million homes

• Most is used by industry in refining, treating metals and processing foods

• Operates similar to a battery. It has 2 electrodes separated by a membrane. Oxygen passes over on electrode and Hydrogen over the other. The hydrogen reacts and is converted to charged hydrogen. Hydrogen ions move through the membrane where they are combined with oxygen and electrons to produce water.

• Unlike batteries, fuel cells never run out.

Hydrogen Fuel CellPros Cons

Water product is pure water Takes energy to produce the hydrogen from water or methane

Ordinary water can be used to obtain hydrogen

Changing from current fossil fuel system to a hydrogen system would be expensive

Doesn’t destroy habitats and has minimal environmental impact

Hydrogen is explosive (but so is gasoline, natural gas and methane)

Energy to produce hydrogen could come from fusion reactor, solar or less polluting sources

At the current time, it’s hard to store hydrogen gas for personal use

Easily transported through pipelinesCan be stored in compounds to make it safer.

Biomass

• Any carbon based, biologically derived fuel source such as wood, manure, charcoal or crops grown for use as biofuel.

• Biodiesel, methane and ethanol. • Good plants to use: switch grass, hemp, corn and

sugarcane. • Biomass can also be used for building materials and

biodegradable paper and plastics• About 15% of the worlds energy supply is from

biomass (mostly in developing nations)

BiomassPros Cons

Renewable energy as long as used sustainably Requires land and fertilizers

Can be sustainable if issue of deforestation and erosion are controlled

Use of inorganic fertilizers, herbicides and pesticides would harm environment

Could supply ½ of the worlds energy needs Corn being diverted to produce ethanol raises food prices

Biomass plantations could be located in less desirable locations and can reduce soil erosion and restore degraded land

Massive deforestation and loss of habitat, resulting in a decrease in biodiversity

Inefficient methods of burning biomass would lead to large levels of air pollution especially Particulate MatterExpensive to transport because its heavy

Not efficient. About 70% of the energy obtained would be lost to heat.

Biomass

• Can also be burned in large incinerators as an energy sourcePro ConCrop residues are available (ex. Sugar cane in Hawaii)

Net-energy yield is low to moderate. Energy required for drying and transporting material to facility is prohibitive.

Ash can be collected and recycled Severe air pollution if not burned in centralized facility

Reduces impact on landfills CO2 production would have a major impact on global warming

Case Study- Biomass

• About 90% of all cars in Brazil run on either alcohol or gasohol (a mix of gas and ethanol)

• Flex fuel engines can run on either. • Alcohol is produced from sugarcane, which is

abundant in Brazil• The use of alcohol and gasohol has had a

negative effect on rainforests.

Wind Energy

• Wind turns giant turbine blades that then power generators. Turbines can be grouped in clusters called windfarms.

Wind energyPros Cons

All electrical needs of US could be met by in in North Dakota, South Dakotas and Texas

Steady wind is required to make investment in wind farms economical. Few places are suitable

Wind farms can be quickly built and built on sea platforms

Backup systems need to be in place for when the wind isn’t blowing

Maintenance is low and farms are automated

Visual pollution

Moderate-to-high net-energy yield May interfere with flight patterns of birds

No pollution. Wind farms are in remote locations so noise pollution is minimal to humans

May interfere with communication, such as microwaves, TV and cell phones

Land underneath turbines can be used for other purposes

Noise Pollution

Small Scale Hydroelectric

• Can be submerged into streams • Generally 100 kW or less• Technology doesn’t impede fish movement or stream

navigation• There are economic incentives for installing small-scale

hydroelectric systems. • Consider this: – The amount of water flow available on a consistent basis– Amount of drop the water has from input to output– Regulatory issues such as water rights

Ocean Waves and Tidal Energy

• The natural movement of tides and waves spin turbines that generate electricity.

• Only a few plants are currently operating worldwide

• They are on the north coast of France and the Bay of Fundy between the US and Canada.

Ocean Waves and Tidal EnergyPros Cons

No pollution Construction is expensive

Few suitable sites Minimal environmental impact

Net-energy yield is moderate Equipment can be damaged by storms and corrosion

Geothermal

• Heat contained in underground rocks and fluit produce pockets of underground dry steam, wet steam or hot water

• This steam can be used to drive turbines which then can generate electricity

• Supplies less than 1% of the US energy needs• Used in Hawaii, Iceland, Japan, Mexico, Russia, and

California• Areas of known resources tend to follow tectonic

plate boundaries.

GeothermalPros ConsModerate net-energy yield Reservoir sites are scarceLimitless and reliable source if managed properly

Sources can be depleted if not managed correctly

Little air pollution Noise, odor and land subsidence

Competitive cost Can degrade ecosystem due to corrosive, thermal or saline wastes

Relevant Law

• Renewable Energy Law, China (2007)• Requires power grid operators to purchase resources from

registered renewable energy producers• Law offers financial incentives to foster renewable energy

development• Offers discounted lending and tax preferences for renewable

energy projects• Designed to protect the environment, prevent energy shortages

and reduce dependence on imported energy• Law includes specific penalties for noncompliance. • Has grown renewable energy usage from 3% in 2003 to 10% by

2020.

Case Study- Bloom Boxes

• A collection of solid oxide fuel cells that use liquid or gas hydrocarbons (such as gas, diesel or propane) to generate electricity on site

• 20% of Bloom Box savings result from avoiding transfer losses associated with transmitting energy over a grid

• 15% of power at eBay is from Boom Boxes.• Google, Wal-Mart, FedEx, Coca-Cola and Bank

of America too