1. ENVIRONMENTAL SCIENCE 13e CHAPTER 13: Energy

2. Core Case Study: Amory Lovins and the Rocky Mountain Institute (1) 1984: home and office building in Snowmass, CO Heat: –Sun –Heavy roof insulation –Thick stone walls –Energy-efficient windows –Waste-heat recovery

3. Core Case Study: Amory Lovins and the Rocky Mountain Institute (2) Sun –99% of heat and hot water –95% of daytime lighting –90% of household electricity Energy-efficient electrical appliances and computers Rocky Mountain Institute –Promotes energy-efficient buildings and transportation

4. 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.

5. Evaluating Energy Resources Energy from the sun Indirect forms of renewable solar energy –Wind –Hydropower –Biomass Commercial energy –Fossil fuels -- nonrenewable

6. Science Focus: Net Energy High-quality energy Second law of thermodynamics Wasted energy Net energy –Ratio of energy produced to energy used to produce it Net energy ratio Nuclear fuel cycle

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 (1) Petroleum (crude oil) –Also called light oil –Trapped underground or under ocean with natural gas –Fossil fuels Extraction –U.S. peak production –Global peak production

9. Dependence on Oil (2) Transportation Refining Petrochemicals

10. 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

11. Major Oil-Supplying Nations Control of oil reserves OPEC Distribution of proven reserves How long will conventional oil last?

12. United States Oil Production and Use (1) U.S. –93% of energy from fossil fuels –39% from crude oil –Produces 9% of world’s crude oil –Uses 25% of world production –Has 2% of proven crude oil reserves

13. United States Oil Production and Use (2) Domestic oil production –Off-shore drilling –Alaska Future U.S. production Consumption versus production Oil imports –2008: imported 58% of crude

14. Oil Sand and Oil Shale Oil sand (tar sand) Bitumen Kerogen Shale Oil World reserves Major environmental problems

15. Natural Gas Is a Useful and Clean-burning Fossil Fuel (1) Natural gas Conventional natural gas Unconventional natural gas Liquefied petroleum gas (LPG) Less carbon dioxide emitted per unit of energy than with crude oil, tar sand, shale oil

16. Natural Gas Is a Useful and Clean-burning Fossil Fuel (2) Liquefied natural gas (LNG) World supply of conventional natural gas – 62-125 years Unconventional natural gas –Coal-bed methane gas –Methane hydrate

17. Coal Is a Plentiful But Dirty Fuel (1) Used in electricity production World’s most abundant fossil fuel U.S. reserves should last about 250 years Sulfur and particulate pollutants Mercury and radioactive pollutants

18. Coal Is a Plentiful But Dirty Fuel (2) Heavy carbon dioxide emissions Pollution control and environmental costs China major builder of coal plants

19. Case Study: The Growing Problem of Coal Ash Highly toxic Often stored in ponds –Ponds can rupture Groundwater contamination EPA: in 2009 called for classifying coal ash as hazardous waste –Opposed by coal companies

20. Clean Coal Campaign Coal industry –Rich and powerful –Fought against labeling carbon dioxide a greenhouse gas “Clean coal” touted by coal industry –Mining harms the environment –Burning creates carbon dioxide and toxic chemicals Plan to capture and store carbon dioxide

21. Converting Coal into Gaseous and Liquid Fuels Synfuels Coal gasification –Synthetic natural gas (SNG) Coal liquefaction –Methanol or synthetic gasoline Extracting and burning coal more cleanly

22. 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, and the potential for spreading nuclear weapons technology.

23. How Does a Nuclear Fission Reactor Work? Nuclear fission Light-water reactors Boil water to produce steam to turn turbines to generate electricity Radioactive uranium as fuel Control rods, coolant, and containment vessels

24. 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

25. 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)

26. 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

27. Nuclear Power Is Vulnerable to Terrorist Acts Insufficient security On-site storage facilities U.S.: 161 million people live within 75 miles of an above-ground nuclear storage site

28. Dealing with Radioactive Wastes High-level radioactive wastes Long-term storage: 10,000–240,000 years Deep burial Detoxify wastes?

29. Case Study: Dealing with Radioactive Wastes in the United States Yucca Mountain, Nevada Concerns over groundwater contamination Possible seismic activity Transportation accidents and terrorism 2009: Obama ends Yucca funding

30. What Do We Do with Worn-Out Nuclear Power Plants? Decommissioning old nuclear power plants Dismantle power plant and store materials Install physical barriers Entomb entire plant

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

32. 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.

33. Improving Energy Efficiency Energy efficiency –How much work we get from each unit of energy we use Reducing energy waste –41% of all commercial energy in U.S. is wasted unnecessarily Numerous economic and environmental advantages

34. Examples of Energy-Wasting Devices Incandescent light bulb Internal combustion engine Nuclear power plants Coal-burning power plants

35. Saving Energy and Money in Industry Cogeneration/Combined Heat and Power (CHP) systems Recycling Energy-saving electric motors Fluorescent lighting Smart grid electricity

36. 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

37. Hybrid and Fuel-Cell Cars Super-efficient and ultralight cars Gasoline-electric hybrid car Plug-in hybrid electric car Hydrogen fuel cells Accessible mass-transit systems as alternative

38. Saving Energy and Money in New Buildings Green architecture Solar cells, fuel cells, eco-roofs, recycled materials Super insulation Straw bale houses

39. 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

40. Why Are We Still Wasting So Much Energy? Energy costs relatively little Lack of government support and economic incentives Inadequate building codes Inadequate appliance standards Lack of information about saving energy

41. 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.

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

43. Benefits of Shifting to Renewable Energy Resources (1) More decentralized, less vulnerable Improve national security Reduce trade deficits Reduce air pollution

44. Benefits of Shifting to Renewable Energy Resources (2) Create jobs Save money Renewable energy handicapped by –Unbalanced, intermittent subsidies –Inaccurate pricing

45. Using Solar Energy to Heat Buildings and Water Passive solar heating system Active solar heating system

46. Solar Energy for High- Temperature Heat and Electricity Solar thermal systems Solar thermal plant Solar cookers Photovoltaic (solar) cells

47. 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

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

49. Energy from Burning Biomass Biomass –Wood –Agricultural waste –Plantations –Charcoal –Animal manure Common in developing countries Carbon dioxide increase in atmosphere

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

51. Energy by Tapping the Earth’s Internal Heat Geothermal energy Geothermal heat pumps Hydrothermal reservoirs –Steam –Hot water Deep geothermal energy

52. 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

53. Science Focus: The Quest to Make Hydrogen Workable Bacteria and Algae Electricity from solar, wind, geothermal Storage: liquid and solid Preventing explosions

54. 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.

55. Transition to a More Sustainable Energy Future (1) For each energy alternative: –How much available next 25-50 years? –Estimated net energy yield –Total costs –Necessary subsidies and tax breaks –How affect economic and military security –Vulnerability to terrorism –Environmental effects

56. Transition to a More Sustainable Energy Future (2) Gradual shift from centralized macropower to decentralized micropower Greatly improved energy efficiency Temporary use of natural gas Decrease environmental impact of fossil fuels

57. Economic, Political, and Educational Strategies to Sustainable Energy Requires government strategies Keep prices low in selected resource to encourage use –Same strategy for fossil fuels and nuclear power Keep prices high in selected resource to discourage use Emphasize consumer education

58. 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.

59. 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.

60. 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.