Ch 10 Energy

1. Ch 10 Energy • Energy Sources and Uses • Coal - Oil - Natural Gas • Nuclear Power • Conservation • Solar Energy • Photovoltaic Cells • Fuel Cells • Energy From Biomass • Energy From Earth’s Forces

2. Energy The capacity to do work heat, light, electricity, and chemical energy are all types of energy

3. Energy Sources and Uses • Energy- The capacity to do work. • Work-Application of force through a distance. • Power- Rate at which work is done or rate of flow of energy. Units of energy • Joule - Amount of work done when a force of 1 Newton is exerted over 1 meter (or about 0.238cal). • Calorie - Amount of energy necessary to heat 1 gram of water 1oC. • Watt- 1 joule/sec 3

4. Daily Per Capita Human Energy Consumption through Time 4

5. Per Capita/yr Energy Use and GDP The higher the standard of living, the greater the use of energy. United States: 5% of the world’s population, uses about 20% of the total energy Source: Massachusetts Institute of Technology

6. Per Capita Consumption • On average, each person in the U.S. and Canada uses more than 300 GJ of energy annually. • In poorest countries of the world, each person generally consumes less than one GJ annually. • Richest 20 countries consume annually : • nearly 80% of natural gas, • 65% of oil, and • 50% of coal production. 6

7. Energy Consumption per Capita 7

8. Energy Consumption Profiles in OECD and non-OECD Countries, 2000 (Organization for Economic Co-operation and Development – 30 members) (most Industrialized Nations) OECD – Europe, North America, Japan, Korea, Turkey, Australia, and New Zealand Non-OECD – includes Russia, China, Brazil, Argentina, and other smaller and developing nations. 8

9. How We Use Energy in the US • Industry - 33% • Residential, commercial buildings - 38% • Transportation - 27% • About 50% of all the energy in primary fuels is lost • during conversion to more useful forms (eg, 2/3 energy of coal lost in thermal conversion, ie, combustion), • while being shipped to the site of end use, or (eg, 10% energy lost in transmission lines) • during use. • Natural gas is our most efficient fossil fuel (10% lost during processing & shipping, 75-95% efficient in furnaces). 9

10. Worldwide Commercial Energy Consumption BP 2003 10

11. U.S. Energy Flow, 2002 (quadrillion Btu or quads) 11

12. World Fossil Fuel Consumption 12

13. Renewable Resources Resources that can be replaced within a few human generations. 13

14. Nonrenewable Resources Resources that cannot be replaced within a few human generations. 14

15. Renewable vs Nonrenewable Resources • Renewable • Alternative fuels • Solar power • Biomass • Hydropower • Nonrenewable • Fossil fuels • Oil • Coal • Natural Gas • Ore deposits of metals 15

16. What is a Resource? Source of raw material used by society How can it be used sustainably? 16

17. Resource Management Maximum Sustainable Yield (MSY) is : harvest rate = renewal rate 17

18. IF theHarvest rate>Renewable rate Then the renewableresource can become Depleted in the short term 18

19. Fossil Fuels • Fossil fuels - organic chemicals that were created by living organisms millions of years ago, buried in sediments, and transformed into energy-rich compounds • Because fossil fuels take so long to form,they are essentially nonrenewable resources. 19

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21. Coal Extraction and Use • Mining & drainage - dangerous to humans and the environment • Coal burning releases large amounts of air pollution (CO2, SO2, NOx , dust, heavy metals, etc), and is the largest single source of acid rain in many areas. • Economic damages - billions of dollars 21

22. One of the largest and most controversial strip mines is at Black Mesa, Arizona • Partially located on Hopi Indian land • Relies on non-renewable 10,000 year old groundwater to transport coal slurry

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24. Oil Extraction and Use The Middle East control two-thirds of all known oil reserves. The U.S. has already used up about 40% of its original recoverable petroleum resource. Drilling - soil and water pollution Combustion - substantial air pollution Controversies – ANWR, Coastal Drilling 24 Photo: Associated press

25. Crude Oil Prices 25

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27. Natural Gas Consumption • Natural gas produces only half as much CO2 as an energy-equivalent amount of coal. • Problems: • difficult to ship across oceans or to store in large quantities • Flaring off - wasted 27

28. Nuclear Power • “Atoms for Peace” in 1953 by Eisenhower (produce enough power ‘to cheap to monitor’) • Nuclear power now produces only about 7% of the U.S. energy supply. • Problemshave made nuclear power much less attractive than was originally expected : • construction costs and • safetyconcerns and…. • waste disposal. 28

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30. Distribution of Nuclear Power Plants in North America 30

31. Nuclear Energy Two types of nuclear power & both involve rearranging the structure of the atom. • Fission - splitting of a radioactive isotope of a heavy element into daughter products (smaller atoms) with the release of energy • Fusion - joining of isotopes of a light element into a heavier element with the release of energy. • All commercial energy generationis run by fission. • The Sun generates heat and light by fusion. • Some nuclear weapons use fusion reactions but controlled fusion is still in the developmental stage. 31

32. Accidents??? Chernobyl - 1986 Three Mile Island - 1979 Public alarm but was under control. Reactors in US are different than the one in Chernobyl and are MUCH safer!! Bad accident!!! Also poor reactor design 32

33. Nuclear Wastes • One of the most difficult problems associated with nuclear power is the disposal of wastes produced during mining, fuel production, reactor operation, and decommissioning of reactors. • Ocean dumping– until 1970? • Radioactive mine wastes, mill tailings • Dry cask storage • High-level waste repository - Yucca Mountain, NV?? • Monitored, retrievablestorage? 33

34. Arctic Ocean permanently contaminated? 1965+ - former Soviet Union disposed of 18 nuclear reactors (7 w/ fuel in the Kara Sea) 34

35. Hanford buried radioactive waste which began leaking, esp into the ground water & Columbia River. Shut down in 1960s. Plant rootsabsorbed the radioactive material and transported it to the ground surface. • Nuclear testingpeaks in 1950-60s. Trees absorb cesium which accumulates in wood. Wood ashfrom trees growing during this time period can be radioactive – 100X higher cesium than other environmental samples. 35

36. ENERGY CONSERVATION • Utilization Efficiencies • Most potential energy in fuel is lost as • In response to 1970’s oil prices, average US automobile gas-mileage increased from 13 mpg in 1975 to 28.8 mpg in 1988. • Falling fuel prices of the 1980’s discouraged further conservation. • waste heat. 36

37. Corporate Average Fuel Economy US Dept of Transportation, March 2005

38. Find more non-renewable oil? Eg, Arctic National Wildlife Refuge 38

39. Hybrid gas-electric engines 39

40. Energy Conversion Efficiencies • Energy Efficiencyis a measure of energy produced compared to energy consumed. • Householdenergy losses can be reduced by one-half to three-fourths by using better insulation, double-paned glass, protective covers, and general sealing procedures.(Indoor Pollution?) • Orient homes to gain advantage of passive solar gain in the winter. 40

41. Heat Losses (Miller 2006) High heat losses = white, red, orange 41

42. Increasing Home Insulation Standard Insulation in U.S. homes = R-12 – R-19 Super-Insulated Homes = R-25 – R-60 Super-insulated homes in Sweden use 90% less energy for heating and cooling than typical homes in the U.S.

43. Mesa Verde NP (SW USA) – many energy efficient features 43

44. Domestic Energy Efficiency Earth-sheltered house in Taos, New Mexico 44

45. Buying energy-efficient appliances can cut your energy consumption considerably. 45