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Energy Efficiency and Renewable Energy Chapter 16

Energy Efficiency and Renewable Energy Chapter 16

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Page 1: Energy Efficiency and Renewable Energy Chapter 16

Energy Efficiency and Renewable Energy

Chapter 16

Page 2: Energy Efficiency and Renewable Energy Chapter 16

Core Case Study: Iceland’s Vision of a Renewable-Energy Economy (1)

Supplies 75% of its primary energy and almost all of its electrical energy using• Geothermal energy• Hydroelectric power

No fossil fuel deposits: imports oil

Bragi Arnason: “Dr. Hydrogen”• Energy vision

Page 3: Energy Efficiency and Renewable Energy Chapter 16

Core Case Study: Iceland’s Vision of a Renewable-Energy Economy (2)

2003: World’s first commercial hydrogen filling station

2003–2007: three prototype fuel-cell buses

2008: 10 Toyota Prius test vehicles• Hydrogen-fueled

Whale-watching boat: partially powered by a hydrogen fuel cell

Page 4: Energy Efficiency and Renewable Energy Chapter 16

The Krafla Geothermal Power Station in Northern Iceland

Page 5: Energy Efficiency and Renewable Energy Chapter 16

16-1 Why Is Energy Efficiency an Important Energy Resource?

Concept 16-1 We could save as much as 43% of all the energy we use by improving energy efficiency.

Page 6: Energy Efficiency and Renewable Energy Chapter 16

We Waste Huge Amounts of Energy (1)

Energy conservation

Energy efficiency

Advantages of reducing energy waste:• Quick and clean• Usually the cheapest to provide more energy• Reduce pollution and degradation• Slow global warming• Increase economic and national security

Page 7: Energy Efficiency and Renewable Energy Chapter 16

We Waste Huge Amounts of Energy (2)

Four widely used devices that waste energy• Incandescent light bulb• Motor vehicle with an internal combustion engine• Nuclear power plant• Coal-fired power plant

Possible alternatives for the “outdated four”

Page 8: Energy Efficiency and Renewable Energy Chapter 16

Flow of Commercial Energy through the U.S. Economy

Page 9: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-2, p. 401

Energy Inputs System Outputs

9%

7%

41%85%U.S.

economy

43%8%

4%3%

Nonrenewable fossil fuels Useful energy

Nonrenewable nuclear PetrochemicalsUnavoidable energy waste

Biomass Unnecessary energy waste

Hydropower, geothermal, wind, solar

Page 10: Energy Efficiency and Renewable Energy Chapter 16

Advantages of Reducing Unnecessary Energy Waste

Page 11: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-3, p. 401

SOLUTIONS

Reducing Energy Waste

Prolongs fossil fuel supplies

Reduces oil imports and improves energy security

Very high net energy yield

Low cost

Reduces pollution and environmental degradation

Buys time to phase in renewable energy

Creates local jobs

Page 12: Energy Efficiency and Renewable Energy Chapter 16

Net Energy Efficiency—Honest Energy Accounting

Net energy efficiency

• the only energy that counts

Page 13: Energy Efficiency and Renewable Energy Chapter 16

Comparison of the Net Energy Efficiency for Two Types of Space Heating

Page 14: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-4, p. 402

Electricity from Nuclear Power Plant

Uranium processing and transportation

(57%)

Uranium mining (95%)

Power plant (31%)

Transmission of electricity

(85%)

Resistance heating (100%)

Uranium 100%

95% 54% 17% 14%

Passive Solar

Window transmission

(90%)Sunlight

100%90%

Waste heat

Waste heat

Waste heat

Waste heat

Waste heat

14%

Page 15: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-4, p. 402

Passive Solar

Window transmission

(90%)Sunlight

100%90%

Waste heat

Electricity from Nuclear Power Plant

Uranium processing and transportation

(57%)

Uranium mining (95%)

Power plant (31%)

Transmission of electricity

(85%)

Resistance heating (100%)

Uranium 100%

95% 54% 17% 14%

Waste heat

Waste heat

Waste heat

Waste heat

14%

Stepped Art

Page 16: Energy Efficiency and Renewable Energy Chapter 16

16-2 How Can We Cut Energy Waste?

Concept 16-2 We have a variety of technologies for sharply increasing the energy efficiency of industrial operations, motor vehicles, and buildings.

Page 17: Energy Efficiency and Renewable Energy Chapter 16

We Can Save Energy and Money in Industry (1)

Cogeneration or combined heat and power (CHP)

Replace energy-wasting electric motors

Recycling materials

Switch from low-efficiency incandescent lighting to higher-efficiency fluorescent and LED lighting

Page 18: Energy Efficiency and Renewable Energy Chapter 16

We Can Save Energy and Money in Industry (2)

Electrical grid system: outdated and wasteful

Utility companies promote use of energy

Dow Chemical Company: improvements in efficiency

Page 19: Energy Efficiency and Renewable Energy Chapter 16

We Can Save Energy and Money in Transportation

Corporate average fuel standards (CAFE) standards• Fuel economy standards lower in the U.S. than

many other countries

Fuel-efficient cars are on the market

Hidden prices in the gasoline

Should there be tax breaks for buying fuel-efficient cars, or feebate?

Page 20: Energy Efficiency and Renewable Energy Chapter 16

Average Fuel Economy of New Vehicles Sold in the U.S. and Other Countries

Page 21: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-5a, p. 404

Page 22: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-5a, p. 404

25Cars

20 Cars, trucks, and SUVs

Trucks and SUVs15

Ave

rag

e fu

el e

con

om

y (m

iles

per

gal

lon

)

10

1975 1980 1985 1990 1995 2000 2005

Year

Page 23: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-5b, p. 404

Page 24: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-5b, p. 404

50

45 Europe

40 Japan

35 China

Mil

es p

er g

allo

n (

mp

g)

(co

nve

rted

to

U.S

. te

st e

qu

ival

ents

)

30 Canada

25United States

20

2002 2004 2006 2008

Year

Page 25: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-5, p. 404

Stepped Art

25Cars

20 Cars, trucks, and SUVs

Trucks and SUVs15

Ave

rag

e f

uel

eco

no

my

(mil

es

per

gal

lon

)

10

1975 1980 1985 1990 1995 2000 2005

Year

50

45 Europe

40 Japan

35China

Mil

es p

er g

allo

n (

mp

g)

(co

nve

rted

to

U.S

. te

st e

qu

ival

ents

)

30 Canada

25United States20

2002 2004 2006 2008

Year

Page 26: Energy Efficiency and Renewable Energy Chapter 16

More Energy-Efficient Vehicles Are on the Way

Superefficient and ultralight cars

Gasoline-electric hybrid car

Plug-in hybrid electric vehicle

Energy-efficient diesel car

Electric vehicle with a fuel cell

Page 27: Energy Efficiency and Renewable Energy Chapter 16

Solutions: A Hybrid-Gasoline-Electric Engine Car and a Plug-in Hybrid Car

Page 28: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-6a, p. 405

Conventional hybridFuel tank

Battery

Internal combustion engine

Transmission Electric motor

Page 29: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-6b, p. 405

Plug-in hybridFuel tank

Battery

Internal combustion engine

Transmission Electric motor

Page 30: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-6, p. 405

Stepped Art

Conventional hybrid Fuel tank

Battery

Internal combustion engine

Transmission Electric motor

Plug-in hybrid

Fuel tank

Battery

Internal combustion engine

Transmission Electric motor

Page 31: Energy Efficiency and Renewable Energy Chapter 16

Science Focus: The Search for Better Batteries

Current obstacles• Storage capacity• Overheating• Flammability

In the future• Lithium-ion battery• Ultracapacitor • Viral battery• Using nanotechnology

Page 32: Energy Efficiency and Renewable Energy Chapter 16

We Can Design Buildings That Save Energy and Money (1)

Green architecture

Living or green roofs

Straw bale houses

U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED)

Page 33: Energy Efficiency and Renewable Energy Chapter 16

We Can Design Buildings That Save Energy and Money (2)

Two buildings that were designed with energy in mind• Georgia Power Company in Atlanta, GA (U.S.)• Ministry of Science and Technology Building in

Beijing, China

Page 34: Energy Efficiency and Renewable Energy Chapter 16

A Green or Living Roof in Chicago, IL (U.S.)

Page 35: Energy Efficiency and Renewable Energy Chapter 16

We Can Save Energy and Money in Existing Buildings (1)

Insulate and plug leaks

Use energy-efficient windows

Stop other heating and cooling losses

Heat houses more efficiently

Page 36: Energy Efficiency and Renewable Energy Chapter 16

We Can Save Energy and Money in Existing Buildings (2)

Heat water more efficiently

Use energy-efficient appliances

Use energy-efficient lighting

Page 37: Energy Efficiency and Renewable Energy Chapter 16

A Thermogram Showing Heat Loss Around Houses and Stores

Page 38: Energy Efficiency and Renewable Energy Chapter 16

Individuals Matter: Ways in Which You Can Save Money Where You Live

Page 39: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-9, p. 409

Attic• Hang reflective foil nearroof to reflect heat.• Use house fan.• Be sure attic insulation isat least 30 centimeters(12 inches).

Bathroom • Install water-saving toilets, faucets, and shower heads.• Repair water leaks promptly.

Kitchen • Use microwave rather than stove or oven as much as possible.• Run only full loads indishwasher and use low- or no-heat drying.• Clean refrigerator coilsregularly.

Basement or utility room • Use front-loading clothes washer. If possible run only full loads with warm or cold water.• Hang clothes on racks for drying.• Run only full loads in clothes dryer and use lower heat setting.• Set water heater at 140° if dishwasher is used and 120° or lower if no dishwasher is used.• Use water heater thermal blanket.• Insulate exposed hot water pipes.• Regularly clean or replace furnace filters.

Outside Plant deciduous trees to block summer sun and let in winter sunlight.

Other rooms • Use compact fluorescentlightbulbs or LEDs and avoidusing incandescent bulbswherever possible.• Turn off lights, computers, TV,and other electronic deviceswhen they are not in use.• Use high efficiency windows;use insulating window coversand close them at night andon sunny, hot days.• Set thermostat as low as youcan in winter and as high asyou can in summer.• Weather-strip and caulk doors,windows, light fixtures, andwall sockets.• Keep heating and coolingvents free of obstructions.• Keep fireplace damper closedwhen not in use.• Use fans instead of, or alongwith, air conditioning.

Page 40: Energy Efficiency and Renewable Energy Chapter 16

Why Are We Still Wasting So Much Energy?

Energy remains artificially cheap

Few large and long-lasting government incentives

What about the rebound effect?

Page 41: Energy Efficiency and Renewable Energy Chapter 16

We Can Use Renewable Energy in Place of Nonrenewable Energy Sources

Renewable energy• Solar energy: direct or indirect• Geothermal energy

Benefits of shifting toward a variety of locally available renewable energy resources

Forms of renewable energy would be cheaper if we eliminate• Inequitable subsidies• Inaccurate prices

Page 42: Energy Efficiency and Renewable Energy Chapter 16

16-3 What Are the Advantages and Disadvantages of Solar Energy?

Concept 16-3 Passive and active solar heating systems can heat water and buildings effectively, and the costs of using direct sunlight to produce high-temperature heat and electricity are coming down.

Page 43: Energy Efficiency and Renewable Energy Chapter 16

We Can Heat Buildings and Water with Solar Energy

Passive solar heating system

Active solar heating system

Countries using solar energy to heat water

Page 44: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Passive and Active Solar Heating for a Home

Page 45: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-10a, p. 411

Page 46: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-10a, p. 411

Vent allows hot air to escape in summer

Summer sun

Heavy insulation

Winter sun

Superwindow

Superwindow

Stone floor and wall for heat storage

PASSIVE

Page 47: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-10b, p. 411

Page 48: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-10b, p. 411

Solar collector Heat to house (radiators or forced air duct)

PumpHeavy insulation

Super- window

Hot water tank

Heat exchanger

ACTIVE

Page 49: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Passive or Active Solar Heating

Page 50: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-11, p. 412

TRADE-OFFS

Passive or Active Solar Heating

Advantages Disadvantages

Energy is free Need access to sun 60% of time

Net energy is moderate (active) to high (passive)

Sun can be blocked by trees and other structures

Quick installation Environmental costs not included in market priceNo CO2 emissions

Very low air and water pollution

Need heat storage system

Very low land disturbance (built into roof or windows)

Active system needs maintenance and repair

High cost (active)

Active collectors unattractive

Moderate cost (passive)

Page 51: Energy Efficiency and Renewable Energy Chapter 16

Rooftop Solar Hot Water on Apartment Buildings in Kunming, China

Page 52: Energy Efficiency and Renewable Energy Chapter 16

Case Study: The Rocky Mountain Institute—Solar Powered Office and Home

Location: Snowmass, CO (U.S.)

No conventional heating system

Heating bills: <$50/year

How is this possible?

Page 53: Energy Efficiency and Renewable Energy Chapter 16

Sustainable Energy: Rocky Mountain Institute in Colorado, U.S.

Page 54: Energy Efficiency and Renewable Energy Chapter 16

We Can Cool Buildings Naturally

Technologies available• Superinsulation and high-efficiency windows• Overhangs or awnings on windows• Light-colored roof• Reflective insulating foil in an attic• Geothermal pumps• Plastic earth tubes underground

Page 55: Energy Efficiency and Renewable Energy Chapter 16

We Can Use Sunlight to Produce High-Temperature Heat and Electricity

Solar thermal systems• Central receiver system• Other collecting systems

Unfeasible for widespread use• High cost• Low new energy yields• Limited suitable sites• Sunny, desert sites

Page 56: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Solar Energy for High-Temperature Heat and Electricity

Page 57: Energy Efficiency and Renewable Energy Chapter 16

Commercial Solar Power Tower Plant Near Seville in Southern Spain

Page 58: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Woman in India Uses a Solar Cooker

Page 59: Energy Efficiency and Renewable Energy Chapter 16

We Can Use Solar Cells to Produce Electricity (1)

Photovoltaic (PV) cells (solar cells)• Convert solar energy to electric energy

Design of solar cells

Benefits of using solar cells

Solar-cell power plants• Near Tucson, AZ (U.S.)• 2007: Portugal

Page 60: Energy Efficiency and Renewable Energy Chapter 16

We Can Use Solar Cells to Produce Electricity (2)

Solar-cell systems being built or planned in• Leipzig, Germany• South Korea• South California (U.S.)• China

Page 61: Energy Efficiency and Renewable Energy Chapter 16

We Can Use Solar Cells to Produce Electricity (3)

Key problem• High cost of producing electricity

Will the cost drop with• Mass production • New designs• Nanotechnology

Page 62: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Solar Cells Can Provide Electricity Using Solar-Cell Roof Shingles

Page 63: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-17a, p. 415

Page 64: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-17a, p. 415

Single solar cell

Boron- enriched silicon

Junction

Phosphorus- enriched silicon

Roof options

Solar shinglesPanels of solar cells

Page 65: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Solar Cells Used to Provide Electricity for a Remote Village in Niger

Page 66: Energy Efficiency and Renewable Energy Chapter 16

Total Costs of Electricity from Different Sources in 2004

Page 67: Energy Efficiency and Renewable Energy Chapter 16

The Solar Power Industry Is Expanding Rapidly

Solar cells: 0.2% of the world’s electricity

2040: could solar cells produce 16%?

Nanosolar: California (U.S.)

Germany: huge investment in solar cell technology

General Electric: entered the solar cell market

Page 68: Energy Efficiency and Renewable Energy Chapter 16

Solar-Cell Power Plant in Arizona, U.S., Is the Largest Solar-Cell Power Plant

Page 69: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Solar Cells, Advantages and Disadvantages

Page 70: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-20, p. 417

TRADE-OFFS

Solar Cells

Advantages Disadvantages

Fairly high net energy yield

Need access to sun

Work on cloudy days

Low efficiency

Easily expanded or moved

Need electricity storage system or backupQuick installation

Environmental costs not included in market priceNo CO2 emissions

Low environmental impact

High costs (but should be competitive in 5–15 years)

Low land use (if on roof or built into walls or windows)

High land use (solar-cell power plants) could disrupt desert areas

Last 20–40 years

Reduces dependence on fossil fuels

DC current must be converted to AC

Page 71: Energy Efficiency and Renewable Energy Chapter 16

16-4 Advantages and Disadvantages of Producing Electricity from the Water Cycle

Concept 16-4 Water flowing over dams, tidal flows, and ocean waves can be used to generate electricity, but environmental concerns and limited availability of suitable sites may limit the use of these energy resources.

Page 72: Energy Efficiency and Renewable Energy Chapter 16

We Can Produce Electricity from Falling and Flowing Water

Hydropower• World’s leading renewable energy source used to

produce electricity• Hydroelectric power: Iceland

Advantages

Disadvantages

Micro-hydropower generators

Page 73: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Large-Scale Hydropower, Advantages and Disadvantages

Page 74: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-21, p. 418

TRADE-OFFSLarge-Scale Hydropower

Advantages Disadvantages

Moderate to high net energy

High construction costs

High efficiency (80%)High environmental impact from flooding land to form a reservoir

Large untapped potential Environmental costs

not included in market priceLow-cost electricity

Long life span High CO2 emissions from rapid biomass decay in shallow tropical reservoirs

No CO2 emissions during operation in temperate areas Danger of collapse

Can provide flood control below dam

Uproots people

Decreases fish harvest below damProvides irrigation

water Decreases flow of natural fertilizer (silt) to land below dam

Reservoir useful for fishing and recreation

Page 75: Energy Efficiency and Renewable Energy Chapter 16

Tides and Waves Can Be Used to Produce Electricity (1)

Produce electricity from flowing water• Ocean tides and waves

So far, power systems are limited • Norway• New York City

Page 76: Energy Efficiency and Renewable Energy Chapter 16

Tides and Waves Can Be Used to Produce Electricity (2)

Disadvantages• Few suitable sites• High costs• Equipment damaged by storms and corrosion

Page 77: Energy Efficiency and Renewable Energy Chapter 16

16-5 Advantages and Disadvantages of Producing Electricity from Wind

Concept 16-5 When environmental costs of energy resources are included in market prices, wind energy is the least expensive and least polluting way to produce electricity.

Page 78: Energy Efficiency and Renewable Energy Chapter 16

Using Wind to Produce Electricity Is an Important Step toward Sustainability (1)

Wind: indirect form of solar energy• Captured by turbines• Converted into electrical energy

Second fastest-growing source of energy

What is the global potential for wind energy?

Wind farms: on land and offshore

Page 79: Energy Efficiency and Renewable Energy Chapter 16

Using Wind to Produce Electricity Is an Important Step toward Sustainability (2)

“Saudi Arabia of wind power”• North Dakota• South Dakota• Kansas• Texas

How much electricity is possible with wind farms in those states?

Page 80: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Wind Turbine and Wind Farms on Land and Offshore

Page 81: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22a, p. 420

Page 82: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22a, p. 420

Gearbox

Electrical generator

Power cable

Wind turbine

Page 83: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22b, p. 420

Page 84: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22b, p. 420Wind farm

Page 85: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22c, p. 420

Page 86: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-22c, p. 420Wind farm (offshore)

Page 87: Energy Efficiency and Renewable Energy Chapter 16

Producing Electricity from Wind Energy Is a Rapidly Growing Global Industry

Countries with the highest total installed wind power capacity• Germany• United States• Spain• India• Denmark

Installation is increasing in several other countries

Page 88: Energy Efficiency and Renewable Energy Chapter 16

Wind Energy Is Booming but Still Faces Challenges

Advantages of wind energy

Drawbacks• Windy areas may be sparsely populated• Winds die down; need back-up energy• Storage of wind energy• Kills migratory birds • “Not in my backyard”

Page 89: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Wind Power, Advantages and Disadvantages

Page 90: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-23, p. 421

TRADE-OFFSWind Power

Advantages DisadvantagesModerate to high net energy yield

Steady winds needed

High efficiencyBackup systems needed when winds are lowModerate capital

costLow electricity cost (and falling)

Plastic components produced from oil

Very low environmental impact

Environmental costs not included in market price

No CO2 emissions High land use for wind farm

Quick construction

Easily expandedVisual pollution

Can be located at seaNoise when located near populated areas

Land below turbines can be used to grow crops or graze livestock

Can kill birds and interfere with flights of migratory birds

Page 91: Energy Efficiency and Renewable Energy Chapter 16

16-6 Advantages and Disadvantages of Biomass as an Energy Source (1)

Concept 16-6A Solid biomass is a renewable resource, but burning it faster than it is replenished produces a net gain in atmospheric greenhouse gases, and creating biomass plantations can degrade soil biodiversity.

Page 92: Energy Efficiency and Renewable Energy Chapter 16

16-6 Advantages and Disadvantages of Biomass as an Energy Source (2)

Concept 16-6B Liquid biofuels derived from biomass can be used in place of gasoline and diesel fuels, but creating biofuel plantations could degrade soil and biodiversity and increase food prices and greenhouse gas emissions.

Page 93: Energy Efficiency and Renewable Energy Chapter 16

We Can Get Energy by Burning Solid Biomass

Biofuels

Production of solid mass fuel• Plant fast-growing trees• Biomass plantations• Collect crop residues and animal manure

Advantages

Disadvantages

Page 94: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Solid Biomass, Advantages and Disadvantages

Page 95: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-24, p. 422

TRADE-OFFSSolid Biomass

Advantages DisadvantagesLarge potential supply in some areas

Nonrenewable if harvested unsustainably

Moderate to high environmental impactModerate costs

No net CO2 increase if harvested, burned, and replanted sustainably

Environmental costs not included in market price

Increases CO2 emissions if harvested and burned unsustainably

Low photosynthetic efficiency

Plantation can be located on semiarid land not needed for crops Soil erosion, water

pollution, and loss of wildlife habitat

Can make use of agricultural, timber, and urban wastes

Often burned in inefficient and polluting open fires and stoves

Plantations could compete with cropland

Plantation can help restore degraded lands

Page 96: Energy Efficiency and Renewable Energy Chapter 16

We Can Convert Plants and Plant Wastes to Liquid Biofuels (1)

Liquid biofuels• Biodiesel• Ethanol

Biggest producers of biofuel• Brazil• The United States• The European Union • China

Page 97: Energy Efficiency and Renewable Energy Chapter 16

We Can Convert Plants and Plant Wastes to Liquid Biofuels (2)

Major advantages over gasoline and diesel fuel produced from oil• Biofuel crops can be grown almost anywhere

• No net increase in CO2 emissions if managed properly

• Available now

Page 98: Energy Efficiency and Renewable Energy Chapter 16

We Can Convert Plants and Plant Wastes to Liquid Biofuels (3)

Studies warn of problems:• Decrease biodiversity• Increase soil degrading, erosion, and nutrient

leaching• Push farmers off their land• Raise food prices

Page 99: Energy Efficiency and Renewable Energy Chapter 16

Case Study: Is Biodiesel the Answer?

Biodiesel production from vegetable oil from various sources

95% produced by The European Union

Jatropha shrub: promising new source

Advantages

Disadvantages

Page 100: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Biodiesel, Advantages and Disadvantages

Page 101: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-25, p. 424

TRADE-OFFS

Biodiesel

Advantages Disadvantages

Reduced CO emissions

Increased NOx emissions and more smog

Reduced CO2 emissions (78%)

Higher cost than regular diesel

High net energy yield for oil palm crops

Environmental costs not included in market price

Low net energy yield for soybean crops

Moderate net energy yield for rapeseed crops May compete with

growing food on cropland and raise food prices

Reduced hydrocarbon emissions

Loss and degradation of biodiversity from crop plantations

Better gas mileage (40%)

Potentially renewable

Can make engines hard to start in cold weather

Page 102: Energy Efficiency and Renewable Energy Chapter 16

Case Study: Is Ethanol the Answer? (1)

Ethanol converted to gasohol

Brazil: “Saudi Arabia of sugarcane” • Saved $50 billion in oil import costs since the

1970s

United States: ethanol from corn • Reduce the need for oil imports?• Slow global warming?• Reduce air pollution?

Page 103: Energy Efficiency and Renewable Energy Chapter 16

Case Study: Is Ethanol the Answer? (2)

Cellulosic ethanol: alternative to corn ethanol

Sources• Switchgrass• Crop residues• Municipal wastes

Advantages

Disadvantages

Page 104: Energy Efficiency and Renewable Energy Chapter 16

Natural Capital: Rapidly Growing Switchgrass in Kansas, U.S.

Page 105: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Ethanol Fuel, Advantages and Disadvantages

Page 106: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-27, p. 426

TRADE-OFFS

Ethanol Fuel

Advantages DisadvantagesHigh octane Lower driving range

Low net energy yield (corn)

Some reduction in CO2 emissions (sugarcane bagasse)

Higher CO2 emissions (corn)Much higher cost

High net energy yield (bagasse and switchgrass)

Environmental costs not included in market price

May compete with growing food and raise food prices

Reduced CO emissions

Higher NOx emissions and more smog

Can be sold as E85 or pure ethanol

Corrosive

Can make engines hard to start in cold weather

Potentially renewable

Page 107: Energy Efficiency and Renewable Energy Chapter 16

ABC Video: MTBE pollution

Page 108: Energy Efficiency and Renewable Energy Chapter 16

16-7 What Are the Advantages and Disadvantages of Geothermal Energy?

Concept 16-7 Geothermal energy has great potential for supplying many areas with heat and electricity and generally has a low environmental impact, but locations where it can be exploited economically are limited.

Page 109: Energy Efficiency and Renewable Energy Chapter 16

Getting Energy from the Earth’s Internal Heat (1)

Geothermal energy: heat stored in• Soil• Underground rocks• Fluids in the earth’s mantle

Geothermal heat pump system• Energy efficient and reliable• Environmentally clean• Cost effective to heat or cool a space

Page 110: Energy Efficiency and Renewable Energy Chapter 16

Getting Energy from the Earth’s Internal Heat (2)

Hydrothermal reservoirs • Iceland

Geothermal energy: two problems• High cost of tapping large-scale hydrothermal

reservoirs• Dry- or wet-steam geothermal reservoirs could be

depleted

Hot, dry rock: another potential source of geothermal energy?

Page 111: Energy Efficiency and Renewable Energy Chapter 16

Natural Capital: A Geothermal Heat Pump System Can Heat or Cool a House

Page 112: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-28, p. 427

Basement heat pump

Page 113: Energy Efficiency and Renewable Energy Chapter 16

Trade Offs: Geothermal Energy, Advantages and Disadvantages

Page 114: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-29, p. 428

TRADE-OFFS

Advantages Disadvantages

Geothermal Energy

Very high efficiency Scarcity of suitable sites

Moderate net energy at accessible sites

Can be depleted if used too rapidly

Environmental costs not included in market priceLower CO2 emissions

than fossil fuelsCO2 emissions

Low cost at favorable sites

Moderate to high local air pollution

Low land use and disturbance Noise and odor (H2S)

Moderate environmental impact

High cost except at the most concentrated and accessible sources

Page 115: Energy Efficiency and Renewable Energy Chapter 16

16-8 The Advantages and Disadvantages of Hydrogen as an Energy Source

Concept 16-8 Hydrogen fuel holds great promise for powering cars and generating electricity, but to be environmentally beneficial, it would have to be produced without the use of fossil fuels.

Page 116: Energy Efficiency and Renewable Energy Chapter 16

Hydrogen Is a Promising Fuel but There Are Challenges (1)

Hydrogen as a fuel• Eliminate most of the air pollution problems• Reduce threats of global warming

Some challenges• Chemically locked in water and organic

compounds • Fuel cells are the best way to use hydrogen

• CO2 levels dependent on method of hydrogen production

Page 117: Energy Efficiency and Renewable Energy Chapter 16

Hydrogen Is a Promising Fuel but There Are Challenges (2)

Production and storage of H2

Hydrogen-powered vehicles: prototypes available

Can we produce hydrogen on demand?

Larger fuel cells

Page 118: Energy Efficiency and Renewable Energy Chapter 16

A Fuel Cell Separates the Hydrogen Atoms’ Electrons from Their Protons

Page 119: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-30, p. 429

AnodePolymerElectrolyteMembrane

Cathode

Air (O2) in

Water(H2O)out

Hydrogengas (H2)in

Protons

Electrons

Page 120: Energy Efficiency and Renewable Energy Chapter 16

Trade-Offs: Hydrogen, Advantages and Disadvantages

Page 121: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-31, p. 430

TRADE-OFFSHydrogen

AdvantagesFuel cell

DisadvantagesCan be produced from plentiful water

Not found as H2 in natureEnergy is needed to produce fuelLow environmental

impact Negative net energyRenewable if produced from renewable energy resources

CO2 emissions if produced from carbon-containing compounds

No CO2 emissions if produced from water

Environmental costs not included in market price

Good substitute for oil Nonrenewable if

generated by fossil fuels or nuclear powerCompetitive price if

environmental and social costs are included in cost comparisons

High costs (that may eventually come down)

Easier to store than electricity

Will take 25 to 50 years to phase inShort driving range for current fuel-cell carsSafer than gasoline

and natural gas No fuel distribution system in place

Nontoxic

High efficiency (45–65%) in fuel cells

Excessive H2 leaks may deplete ozone in the atmosphere

Page 122: Energy Efficiency and Renewable Energy Chapter 16

16-9 How Can We Make a Transition to a More Sustainable Energy Future?

Concept 16-9 We can make a transition to a more sustainable future if we greatly improve energy efficiency, use a mix of renewable energy resources, and include environmental costs in the market prices of all energy resources.

Page 123: Energy Efficiency and Renewable Energy Chapter 16

Choosing Energy Paths (1)

How will energy policies be created?

Supply-side, hard-path approach

Demand-side, soft-path approach

Page 124: Energy Efficiency and Renewable Energy Chapter 16

Choosing Energy Paths (2)

General conclusions about possible energy paths• Gradual shift to smaller, decentralized

micropower systems• Transition to a diverse mix of locally available

renewable energy resources Improved energy efficiency• How?

• Fossil fuels will still be used in large amounts • Why?

Page 125: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Decentralized Power System

Page 126: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-32, p. 431

Small solar-cell power plantsBioenergy power plants Wind farm

Fuel cellsRooftop

solar-cell arrays

Solar-cell rooftop

systems

Transmission and distribution system

Commercial

Small wind turbine

Residential

Industrial Microturbines

Page 127: Energy Efficiency and Renewable Energy Chapter 16

Solutions: Making the Transition to a More Sustainable Energy Future

Page 128: Energy Efficiency and Renewable Energy Chapter 16

Fig. 16-33, p. 432

SOLUTIONSMaking the Transition to a More Sustainable Energy Future

Improve Energy Efficiency More Renewable Energy

Increase fuel-efficiency standards for vehicles, buildings, and appliances

Greatly increase use of renewable energyProvide large subsidies and tax credits for use of renewable energy

Mandate government purchases of efficient vehicles and other devices

Include environmental costs in prices for all energy resourcesEncourage government purchase of renewable energy devices

Provide large tax credits or feebates for buying efficient cars, houses, and appliances

Greatly increase renewable energy research and development

Reduce Pollution and Health RiskOffer large tax credits for investments in energy efficiency

Cut coal use 50% by 2020

Phase out coal subsidiesReward utilities for reducing demand for electricity Levy taxes on coal and oil use

Greatly increase energy efficiency research and development

Phase out nuclear power subsidies, tax breaks, and loan guarantees

Page 129: Energy Efficiency and Renewable Energy Chapter 16

Economics, Politics, Education, and Sustainable Energy Resources

Government strategies:• Keep the prices of selected energy resources

artificially low to encourage their use• Keep energy prices artificially high for selected

resources to discourage their use• Consumer education

Page 130: Energy Efficiency and Renewable Energy Chapter 16

What Can you Do? Shifting to Sustainable Energy Use

Page 131: Energy Efficiency and Renewable Energy Chapter 16

Case Study: California’s Efforts to Improve Energy Efficiency

High electricity costs

Reduce energy waste

Use of energy-efficient devices

Strict building standards for energy efficiency