1. ENVIRONMENTAL SCIENCE 13e CHAPTER 13: Energy

2. 13-1 What Major Sources of Energy Do We Use? Concept 13-1A About three-quarters of the world’s commercial energy comes from nonrenewable fossil fuels, and the rest comes from nonrenewable nuclear fuel and renewable sources. Concept 13-1B Net energy is the amount of high-quality energy available from a resource minus the amount of energy needed to make it available.

3. Evaluating Energy Resources Energy from the sun Indirect forms of renewable solar energy –Wind –Hydropower –Biomass Nonrenewable energy –Fossil fuels –Nuclear fuel

4. Fig. 13-2, p. 298

5. Science Focus: Net Energy High-quality energy ( ＋ ) Second law of thermodynamics( － ) Wasted energy( － ) Net energy ratio –Ratio of energy produced to energy used to produce it Nuclear fuel has low ratio.

6. Fig. 13-A, p. 299 5.8 Transportation 4.9 Natural gas 4.1 1.4 1.2 1.1 (but can reach 1.5) Gasoline (refined crude oil) Ethanol from sugarcane residue Coal liquefaction Oil shale Space Heating Oil Electric heating (nuclear plant) Passive solar Natural gas Active solar Coal gasification Electric heating (coal-fired plant) Electric heating (natural-gas-fired plant) High-Temperature Industrial Heat Direct solar (concentrated) Coal gasification Oil Natural gas Underground-mined coal Surface-mined coal 0.9 1.5 4.7 4.9 25.8 0.3 0.4 1.9 1.5 4.5 4.9 28.2 8.0 5.4 Ethanol from corn Ethanol from switchgrass

7. 13-2 What Are the Advantages and Disadvantages of Fossil Fuels? Concept 13-2 Oil, natural gas, and coal are currently abundant and relatively inexpensive, but using them causes air and water pollution, degrades large areas of land, and releases greenhouse gases to the atmosphere.

8. Dependence on Oil Petroleum (crude oil 原油 ) –Also called light oil –Trapped underground or under ocean with natural gas –Fossil fuels Extraction Transportation Refining

9. Fig. 13-2, p. 281 Pipeline Pump Oil drilling platform CoalContour strip mining Geothermal energy Oil well Geothermal power plant Pipeline Oil and natural gas Oil storage Coal seam Area strip mining Mined coal Drilling tower Water penetrates down through the rock Gas well Hot water storage

10. Offshore Floating Oil Production Platform in the Gulf of Mexico Fig. 13-1, p. 279

11. Asphalt Gases Lowest Boiling Point Highest Boiling Point Gasoline Aviation fuel Heating oil Diesel oil Heated crude oil Furnace Naphtha Grease and wax Fig. 13-3, p. 300

13. How Long Will Crude Oil Supplies Last? Crude oil is the single largest source of commercial energy in world and U.S. Proven oil reserves –Can be extracted profitably at today’s prices with today’s technology –80% depleted between 2050 and 2100

14. Major Oil-Supplying Nations OPEC controls most of the world’s oil supplies OPEC (Organization of Petroleum Exporting Countries, 13)---78% Algeria, Angola, Ecuador, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, Venezuela Distribution of proven reserves Saudi Arabia---20% How long will conventional oil last? world:42-93yr, U.S.:10-48yr

15. Oil Sand and Oil Shale ■ Oil sand (tar sand)---a mixture of clay, sand, water, and bitumen ( 瀝青, a combustible organic material with a high sulfur content) Bitumen→→ a low-sulfur synthetic crude oil World reserves (3/4 in Canada) ■ Oil shale ( 油頁岩 ) 含 Kerogen ( 油母 ) Shale Oil ( 頁岩油 ) ← 將油頁岩壓碎加熱蒸 餾

16. Fig. 13-6, p. 303

17. Natural Gas Is a Useful and Clean-burning Fossil Fuel Natural gas ( 主成分為甲烷, 50-90%, 及少量的乙烷 丙烷 丁烷 ) Conventional natural gas ( 在石油上方 ) Unconventional natural gas ( 單獨存在 ) Liquefied petroleum gas (LPG) 液化石油氣 ( 主要為丙烷及丁烷 ) ( 儲存壓力槽中 ) Liquefied natural gas (LNG) 液化天然氣 ( 主要為甲烷 ) 通常以壓力管線輸送 World supply of conventional natural gas – 62-125 years

18. Fig. 13-8, p. 304 Conventional Natural Gas Nonrenewable resource Releases CO 2 when burned Government subsidies Environmental costs not included in market price Methane (a greenhouse gas) can leak from pipelines Difficult to transfer from one country to another Can be shipped across ocean only as highly explosive LNG Ample supplies High net energy yield Low cost Less air pollution than other fossil fuels Lower CO 2 emissions than other fossil fuels Easily transported by pipeline Low land use Good fuel for fuel cells, gas turbines, and motor vehicles Trade-Offs Advantages Disadvantages

19. Coal Is a Plentiful But Dirty Fuel World’s most abundant fossil fuel Stages of coal formation* buried plants→peat( 泥炭 ) →lignite( 褐煤 ) →bituminous( 煙煤 ) →anthracite( 無煙煤 ) Carbon (Sulfur, mercury, radioactive pollutants) Used in electricity production* U.S. reserves should last about 250 years Pollution control and environmental costs

20. Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Low heat content; low sulfur content; limited supplies in most areas Partially decayed plant matter in swamps and bogs; low heat content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Increasing heat and carbon content Increasing moisture content Heat Pressure Anthracite (hard coal) Fig. 13-9, p. 305

21. Stack Waste heat Cooling tower transfers waste heat to atmosphere Pulverizing mill TurbineCoal bunker Generator Cooling loop Condenser Boiler Filter Toxic ash disposal Fig. 13-10, p. 306

23. Fig. 13-12, p. 307 Disadvantages Severe land disturbance, air pollution, and water pollution Severe threat to human health when burned Environmental costs not included in market price Large government subsidies High CO 2 emissions when produced and burned Radioactive particle and toxic mercury emissions Air pollution can be reduced with improved technology Well-developed technology Low cost High net energy yield Ample supplies (225–900 years) Trade-Offs Coal Advantages

24. 13-3 What Are the Advantages and Disadvantages of Nuclear Energy? Concept 13-3 The nuclear power fuel cycle has a low environmental impact and a very low accident risk, but its use has been limited because of high costs, a low net energy yield, long-lived radioactive wastes, vulnerability to sabotage( 破壞行動 ), and the potential for spreading nuclear weapons technology.

25. How Does a Nuclear Fission Reactor Work? Nuclear fission( 核分裂 ) Light-water reactors ( 輕水式反應爐 )* Boil water to produce steam to turn turbines to generate electricity Radioactive uranium as fuel Control rods ( 控制棒 ), coolant ( 冷卻 劑 ), and containment vessels ( 圍阻體 )

26. Cool water input Small amounts of radioactive gases Periodic removal and storage of radioactive wastes and spent fuel assemblies Periodic removal and storage of radioactive liquid wastes Control rods Heat exchanger Containment shell Steam Water Uranium fuel input (reactor core) Hot coolant Coolant Moderator Coolant passage Shielding Waste heat Water source (river, lake, ocean) Useful electrical energy About 25% GeneratorTurbine Hot water output Condenser Pressure vessel Fig. 13-14, p. 310 Pump Waste heat Pump

27. Fig. 13-14, p. 310

28. Safety and Radioactive Wastes On-site storage of radioactive wastes Safety features of nuclear power plants Nuclear fuel cycle Reactor life cycle Large amounts of very radioactive wastes

29. Fig. 13-15, p. 311

31. Fuel assemblies Fuel fabrication Enrichment of UF 6 Temporary storage of spent fuel assemblies underwater or in dry casks Low-level radiation with long half-life Geologic disposal of moderate and high-level radioactive wastes (conversion of enriched UF 6 to UO 2 and fabrication of fuel assemblies) Uranium-235 as UF6 Plutonium- 239 as PuO 2 Decommissioning of reactor Reactor Spent fuel reprocessing Conversion of U 3 O 8 to UF 6 Fig. 13-16, p. 312 Open fuel cycle today Recycling of nuclear fuel Mining uranium ore (U 3 O 8 )

32. What Happened to Nuclear Power? Optimism of 1950s is gone Comparatively expensive source of power No new plants in U.S. since 1978 Disposing of nuclear waste is difficult Three Mile Island (1979)

33. Case Study: Chernobyl Disaster Ukraine (1986) Explosions and partial meltdown Huge radioactive release to atmosphere Estimated death toll: 9,000–212,000 Radioactive fallout and long-term health effects Lesson – worldwide consequences

34. Fig. 13-17, p. 313 Conventional Nuclear Fuel Cycle Cannot compete economically without huge government subsidies Low net energy yield High environmental impact (with major accidents) Environmental costs not included in market price Risk of catastrophic accidents No widely acceptable solution for long-term storage of radioactive wastes Subject to terrorist attacks Spreads knowledge and technology for building nuclear weapons Large fuel supply Low environmental impact (without accidents) Emits 1/6 as much CO 2 as coal Moderate land disruption and water pollution (without accidents) Moderate land use Low risk of accidents because of multiple safety systems (except for Chernobyl-type reactors) Trade-Offs Disadvantages Advantages

35. Fig. 13-18, p. 314 Coal vs. Nuclear Ample supply of uranium Low net energy yield Low air pollution Lower CO 2 emissions Much lower land disruption from surface mining Moderate land use High cost (even with huge subsidies) Ample supply High net energy yield Very high air pollution High CO 2 emissions High land disruption from surface mining High land use Low cost (with huge subsidies) CoalNuclear Trade-Offs

36. What Is the Future for Nuclear Power? Reduce dependence on foreign oil Reduce global warming Advanced light-water reactors Nuclear fusion ( 核融合 ) How to develop relatively safe nuclear power with a high net energy yield?

37. 13-4 Why Is Energy Efficiency an Important Energy Source? Concept 13-4 The United States could save as much as 43% of all the energy it uses by improving the energy efficiency of industrial operations, motor vehicles, and buildings.

38. OutputsSystemEnergy Inputs 43% 7% 9% 3% 4% 41% 85% 8% U.S. economy Fig. 13-19, p. 319 Nonrenewable fossil fuels Nonrenewable nuclear Hydropower, geothermal, Wind, solar Biomasss Useful energy Petrochemicals Unavoidable energy waste Unnecessary energy

39. Examples of Energy-Wasting Devices Incandescent light bulb( 白熱燈泡 ), (90%-95% waste) Internal combustion engine( 內燃引擎 ), (75-80%) Nuclear power plants (86%) Coal-burning power plants (66%)

41. Saving Energy and Money in Industry Cogeneration/Combined Heat and Power (CHP) systems Recycling Energy-saving electric motors Incandescent lighting →Fluorescent lighting →LED (light emitting diode) lighting Smart grid electricity

42. Saving Energy and Money in Transportation 2/3 of U.S. oil consumption Low fuel-efficiency standards for vehicles Hidden costs: $12/gallon of gas Raise gasoline taxes/cut payroll and income taxes Tax breaks for fuel-efficient vehicles

43. Stepped Art Fig. 13-21, p. 320 25 Cars 20 Cars, trucks, and SUVs Trucks and SUVs 15 Average fuel economy (miles per gallon) 10 19751980 1985 1990199520002005 Year 50 45 Europe 40 Japan 35 China Miles per gallon (mpg) (converted to U.S. test equivalents) 30 Canada 25 United States 20 2002 20042006 2008 Year

44. Hybrid and Fuel-Cell Cars Super-efficient and ultralight cars Gasoline-electric hybrid car ( 油電混合車 ) Plug-in hybrid electric car Hydrogen fuel cells ( 燃料電池 ) Accessible mass-transit systems as alternative

45. Stepped Art Conventional hybridFuel tank Battery Internal combustion engine TransmissionElectric motor Plug-in hybrid Fuel tank Battery Internal combustion engine Transmission Electric motor Fig. 13-22, p. 321

46. Saving Energy and Money in New Buildings Green architecture ( 綠建築 ) Solar cells, fuel cells, eco-roofs, recycled materials Straw bale houses ( 稻草梱房屋 )

47. Energy-efficient Straw Bale House Fig. 13-23, p. 302

48. Saving Energy in Existing Buildings Insulate and plug leaks Use energy-efficient windows Heat houses more efficiently Heat water more efficiently Use energy-efficient appliances Use energy-efficient lighting

49. Fig. 13-23, p. 322

50. Fig. 13-24, p. 324 Outside Plant deciduous trees to block summer sun and let in winter sunlight. Other rooms Use compact fluorescent lightbulbs or LEDs and avoid using incandescent bulbs wherever possible. Turn off lights, computers, TV, and other electronic devices when they are not in use. Use high efficiency windows; use insulating window covers and close them at night and on sunny, hot days. Set thermostat as low as you can in winter and as high as you can in summer. Weather-strip and caulk doors, windows, light fixtures, and wall sockets. Keep heating and cooling vents free of obstructions. Keep fireplace damper closed when not in use. Use fans instead of, or along with, air conditioning. Bathroom Install water-saving toilets, faucets, and shower heads. Repair water leaks promptly. Stepped Art Attic Hang reflective foil near roof to reflect heat. Use house fan. Be sure attic insulation is at least 30 centimeters (12 inches). Kitchen Use microwave rather than stove or oven as much as possible. Run only full loads in dishwasher and use low- or no-heat drying. Clean refrigerator coils regularly. 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.

51. 13-5 What Are Advantages/Disadvantages of Renewable Energy Resources? Concept 13-5 Using a mix of renewable energy sources – especially sunlight, wind, flowing water, sustainable biomass, and geothermal energy – can drastically reduce pollution, greenhouse gas emissions, and biodiversity losses.

52. Renewable Energy Sustainability mostly depends on solar energy –Direct form: from the sun Indirect forms –Wind –Moving water –Biomass Geothermal

53. Benefits of Shifting to Renewable Energy Resources More decentralized, less vulnerable Improve national security Reduce trade deficits Reduce air pollution Create jobs Save money Renewable energy handicapped by –Unbalanced, intermittent subsidies –Inaccurate pricing

54. Using Solar Energy to Heat Buildings and Water Passive solar heating system 直接吸收太陽能並將之儲存於結構內 Active solar heating system 有幫浦抽送水至屋頂接收太陽的熱能

55. Passive and Active Solar Heating

56. Supplement 9, Fig. 5, p. S41

57. Solar Energy for High- Temperature Heat and Electricity Solar thermal systems ( 太陽熱能系統 ) Solar thermal plant ( 太陽熱能發電廠 ) Solar cookers( 太陽能烹調器 ) Photovoltaic (solar) cells ( 太陽能電池 )

58. Fig. 13-27, p. 326 Trade-Offs Low efficiency Low net energy High costs Environmental costs not included in market price Needs backup or storage system Needs access to sun most of the time May disturb desert areas Costs reduced with natural gas turbine backup No CO 2 emissions Fast construction (1–2 years) Moderate environmental impact AdvantagesDisadvantages Solar Energy for High-Temperature Heat and Electricity

60. Boron- enriched silicon Phosphorus- enriched silicon Junction Single solar cell Solar-cell roof Panels of solar cells Solar shingles 屋瓦 Roof options Fig. 13-29, p. 328

61. Fig. 13-30, p. 328

62. Fig. 13-31, p. 328 Solar Cells 太陽能電池 Need access to sun Low efficiency Need electricity storage system or backup Environmental costs not included in market price High costs (but should be competitive in 5–15 years) High land use (solar-cell power plants) could disrupt desert areas DC current must be converted to AC Reduces dependence on fossil fuels Low land use (if on roof or built into walls or windows) Last 20–40 years Low environmental impact No CO 2 emissions Easily expanded or moved Quick installation Work on cloudy days Fairly high net energy yield Trade-Offs DisadvantagesAdvantages

63. Producing Electricity from Flowing Water Hydropower –Leading renewable energy source –Much unused capacity Dams and reservoirs –Turbines generate electricity –Eventually fill with silt Micro-hydro generators

64. Fig. 13-32, p. 329 Large-Scale Hydropower High construction costs High environmental impact from flooding land to form a reservoir Environmental costs not included in market price High CH 4 emissions from rapid biomass decay in shallow tropical reservoirs Danger of collapse Uproots people Decreases fish harvest below dam Decreases flow of natural fertilizer (silt) to land below dam Moderate to high net energy High efficiency (80%) Large untapped potential Low-cost electricity Long life span No CO 2 emissions during operation in temperate areas Can provide flood control below dam Provides irrigation water Reservoir useful for fishing and recreation DisadvantagesAdvantages Trade-Offs

65. Producing Electricity from Wind Indirect form of solar energy World’s second fastest-growing source of energy Vast potential –Land –Offshore

69. Supplement 9, Fig. 8, p. S43

70. Fig. 13-34, p. 331 Trade-Offs Steady winds needed Backup systems needed when winds are low Plastic components produced from oil Environmental costs not included in market price High land use for wind farm Visual pollution Noise when located near populated areas Can kill birds and interfere with flights of migratory birds if not sited properly Moderate to high net energy yield High efficiency Moderate capital cost Low electricity cost (and falling) Very low environmental impact No CO 2 emissions Quick construction Easily expanded Can be located at sea Land below turbines can be used to grow crops or graze livestock Advantages Disadvantages Wind Power

71. Energy from Burning Biomass Biomass ( 生質量 ) –Wood –Agricultural waste –Plantations ( 種植生長快速的植物 ) –Charcoal ( 木炭 ) –Animal manure Common in developing countries Carbon dioxide increase in atmosphere

72. Burning Cow Dung ( 牛糞 ) Fig. 13-35, p. 312

73. Converting Plant Matter to Liquid Biofuel Biofuels –Ethanol and biodiesel ( 生質柴油 ) –Crops can be grown in most countries –No net increase in carbon dioxide emissions –Available now Sustainability

74. Fig. 13-35, p. 333 Increased NO x emissions and more smog Higher cost than regular diesel Environmental costs not included in market price Low net energy yield for soybean crops May compete with growing food on cropland and raise food prices Loss and degradation of biodiversity from crop plantations Can make engines hard to start in cold weather Reduced CO emissions Reduced CO 2 emissions (78%) High net energy yield for oil palm crops Moderate net energy yield for rapeseed crops Reduced hydrocarbon emissions Better gas mileage (40%) Potentially renewable Trade-Offs AdvantagesDisadvantages Biodiesel

75. Fig. 13-36, p. 334 SWITCHGRASS

76. Fig. 13-37, p. 335 Lower driving range Low net energy yield (corn) Higher CO 2 emissions (corn) Much higher cost Environmental costs not included in market price May compete with growing food and raise food prices Higher NO x emissions and more smog Corrosive Can make engines hard to start in cold weather High octane Some reduction in CO 2 emissions (sugarcane bagasse) High net energy yield (bagasse and switchgrass) Can be sold as a mixture of gasoline and ethanol or as pure ethanol Potentially renewable Trade-Offs AdvantagesDisadvantages Ethanol Fuel

77. Energy by Tapping the Earth’s Internal Heat Geothermal energy ( 地熱 ) Geothermal heat pumps ( 地熱空調系統 ) Hydrothermal reservoirs –Dry steam (water vapor) –Wet steam (water vapor + water droplet) –Hot water Deep geothermal energy ( ≧ 5km 岩層 )

78. Supplement 9, Fig. 9, p. S43

79. Fig. 13-38, p. 336 Very high efficiency Scarcity of suitable sites Can be depleted if used too rapidly Environmental costs not included in market price CO 2 emissions Moderate to high local air pollution Noise and odor (H 2 S) High cost except at the most concentrated and accessible sources Moderate environmental impact Low land use and disturbance Low cost at favorable sites Lower CO 2 emissions than fossil fuels Moderate net energy at accessible sites Trade-Offs AdvantagesDisadvantages Geothermal Energy

80. Can Hydrogen Replace Oil? Hydrogen is environmentally friendly Problems –Most hydrogen is in water –Net energy yield is negative –Fuel is expensive –Air pollution depends on production method –Storage

81. Fig. 13-39, p. 337 Not found as H 2 in nature Energy is needed to produce fuel Negative net energy CO 2 emissions if produced from carbon-containing compounds Environmental costs not included in market price Nonrenewable if generated by fossil fuels or nuclear power High costs (that may eventually come down) Will take 25 to 50 years to phase in Short driving range for current fuel-cell cars No fuel distribution system in place Excessive H 2 leaks may deplete ozone in the atmosphere Can be produced from plentiful water Low environmental impact Renewable if produced from renewable energy resources No CO 2 emissions if produced from water Good substitute for oil Competitive price if environmental and social costs are included in cost comparisons Easier to store than electricity Safer than gasoline and natural gas Nontoxic High efficiency (45–65%) in fuel cells Trade-Offs AdvantagesDisadvantages Hydrogen Fuel cell

82. 13-6 How Can We Make the Transition to a More Sustainable Energy Future? Concept 13-6 We can make a transition to a more sustainable energy future by greatly improving energy efficiency, using a mix of renewable energy resources, and including environmental costs of energy resources in their market prices.

83. Transition to a More Sustainable Energy Future Gradual shift from centralized macropower to decentralized micropower Greatly improved energy efficiency Temporary use of natural gas Decrease environmental impact of fossil fuels

84. Bioenergy power plants Microturbines Solar-cell rooftop systems Wind farm Commercial Rooftop solar- cell arrays Residential Smart electrical and distribution system Small wind turbine Industrial Small solar-cell power plants Fuel cells Fig. 13-40, p. 339

85. Economic, Political, and Educational Strategies to Sustainable Energy Requires government strategies Keep prices low in selected resource to encourage use Keep prices high in selected resource to discourage use Emphasize consumer education

86. Three Big Ideas from This Chapter - #1 Energy resources should be evaluated on the basis of their potential supplies, how much net useful energy they provide, and the environmental impact of using them.

87. Three Big Ideas from This Chapter - #2 Using a mix of renewable energy – especially sunlight, wind, flowing water, sustainable biofuels, and geothermal energy – can drastically reduce pollution, greenhouse gas emissions, and biodiversity losses.

88. Three Big Ideas from This Chapter - #3 Making the transition to a more sustainable energy future requires sharply reducing energy waste, using a mix of environmentally friendly renewable energy resources, and including the harmful environmental costs of energy resources in their market prices.