Energy Efficiency and Nonrenewable energy Linda Lacava APES

Energy Efficiency and Nonrenewable energy Linda Lacava APES Chapter 15

Nuclear power Geothermal, 6% solar, wind 2. 5% Hydropower 4. 5% Nuclear power 8% Geothermal, solar, wind 1% Hydropower, 3% Natural gas 21% Biomass 11% Coal 23% Coal 22% Oil 33% World Biomass 3% Oil 39% United States Fig. 15 -3, p. 373

The Importance of Improving Energy Efficiency Energy Inputs System Ø Net useful energy Outputs 9% 7% Ø Life cycle cost 84% Least Efficient Ø Incandescent lights Ø Internal combustion engine Ø Nuclear power plants U. S. economy and lifestyles 7% 5% 4% Nonrenewable fossil fuels Nonrenewable nuclear Hydropower, geothermal, wind, solar Biomass 41% 43% Useful energy Petrochemicals Unavoidable energy waste Unnecessary energy waste

Ways to Improve Energy Efficiency Ø Insulation Ø Elimination of air leaks Ø Cogeneration Ø Efficient electric motors Ø High-efficiency lighting Ø Increasing fuel economy

Opec countries Saudi Arabia (11. 9%), Iran (5. 1%), Venezuela (4. 7%), Iraq (3. 6%), United Arab Emirates (3. 2%), Nigeria (2. 9), Libya (2%), Indonesia (2%), Algeria (1. 6%), Qatar (1%) Non-Opec countries United States (10. 3%), Russia (8. 8%), Mexico (4. 8%), China (4. 6%), Norway (4. 3%), UK (4%), Canada (3. 5%) (Percentages of world oil output)

Fig. 15 -4 a, p. 375

TRADE-OFFS Conventional Oil Advantages Disadvantages Ample supply for 42– 93 years Need to find substitutes within 50 years Low cost Large government subsidies High net energy yield Environmental costs not included in market price Easily transported within and between countries Low land use Technology is well developed Efficient distribution system Artificially low price encourages waste and discourages search for alternatives Pollutes air when produced and burned Releases CO 2 when burned Can cause water pollution Fig. 15 -6, p. 379

TRADE-OFFS Conventional Natural Gas Advantages Disadvantages 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 Nonrenewable resource Releases CO 2 when burned Gas turbine 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 Fig. 15 -10, p. 382

TRADE-OFFS Heavy Oils from Oil Shale and Oil Sand Advantages Disadvantages Moderate cost (oil sand) High cost (oil shale) Low net energy yield Large potential supplies, especially oil sands in Canada Easily transported within and between countries Efficient distribution system in place Technology welldeveloped (oil sand) Environmental costs not included in market price Large amounts of water needed for processing Severe land disruption Severe water pollution Air pollution and CO 2 emissions when produced and burned Fig. 15 -9, p. 380

Fig. 15 -8, p. 380

Increasing heat and carbon content Increasing moisture content Lignite Peat (brown coal) (not a coal) Anthracite (hard coal) Bituminous (soft coal) Heat Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas Stepped Art Fig. 15 -11, p. 383

Fig. 15 -13, p. 384

TRADE-OFFS Coal Advantages Ample supplies (225– 900 years) High net energy yield Low cost Well-developed technology Air pollution can be reduced with improved technology 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 Fig. 15 -15, p. 385

TRADE-OFFS Synthetic fuels Advantages Disadvantages Large potential supply Low to moderate net energy yield Higher cost than coal Vehicle fuel Requires mining 50% more coal Environmental costs not included in market price Moderate cost High environmental impact Large government subsidies Lower air pollution than coal when burned High water use Higher CO 2 emissions than coal Fig. 15 -16, p. 386

TRADE-OFFS Conventional Nuclear Fuel Cycle Advantages Disadvantages Large fuel supply Cannot compete economically without huge government subsidies Low net energy yield High environmental impact (with major accidents) Low environmental impact (without accidents) Emits 1/6 as much CO 2 as coal Moderate land disruption and water pollution (without accidents) Environmental costs not included in market price Moderate land use No widely acceptable solution for long-term storage of radioactive wastes Low risk of accidents because of multiple safety systems (except for Chernobyl-type reactors) Risk of catastrophic accidents Subject to terrorist attacks Spreads knowledge and technology for building nuclear weapons Fig. 15 -21, p. 391

TRADE-OFFS Coal vs. Nuclear Coal Nuclear Ample supply of uranium High net energy yield Very high air pollution High CO 2 emissions High land disruption from surface mining Low net energy yield Low air pollution Low CO 2 emissions Much lower land disruption from surface mining High land use Moderate land use Low cost (with huge subsidies) High cost (even with huge subsidies) Fig. 15 -22, p. 392

Dealing with Nuclear Waste Ø Low-level waste Ø High-level waste Ø Underground burial Ø Disposal in space Ø Burial in ice sheets Ø Dumping into subduction zones Ø Burial in ocean mud