1. Chapter 12 Nonrenewable Energy Resources

2. All Energy Use Has Consequences Oil spill off the coast of Santa Barbara in 1969 11.4 million liters (3 million gallons) March 1989 Exxon Valdez spilled 53 million gallons crashed into a reef in Prince William Sound, Alaska. April 2010 BP Deepwater Horizon oil well suffered a blowout releasing 206 million gallons.

3. In 2005 15 workers died in an explosion in a BP refinery in Texas. Combustion process emits pollutants. April 2010 an explosion in WV killed 29 coal miners. Natural gas (“clean” fossil fuel) has lower particulate emissions. Finding natural gas is detrimental to the environment (Thumper Trucks). Use of water contaminates water. Building pipelines is disruptive to the environment.

5. Nonrenewable Energy Accounts for Most of Our Energy Use Non-renewable: once used up cannot be replenished. Fossil Fuels: derived from biological material that became fossilized millions of years ago. Nuclear Fuels: are derived from radioactive materials that give off energy.

6. Worldwide Patterns of Energy Use Determined by resource availability and affordability. Basic unit of energy is the joule (J). A gigajoule(GJ) is 1 billion joules (1x10 9) about 8 gallons of gasoline. An exajoule (EJ) is 1 billion(1x10 9 ) gigajoules. Quadrillion=s 1x10 15 BTU

7. Oil, coal, and natural gas are the three largest energy sources. Commercial Energy Sources: those bought and sold (coal, oil, and natural gas). Subsistence Energy Sources: those gathered by individuals for their own immediate needs (developing countries).

10. The United States The US produces about 70% of its energy needs. 30% comes from other countries, primarily petroleum imports. Industry uses the most followed by transportation.

13. Energy Types and Quality Gasoline has good energy-mass ration, can provide energy relatively fast. Produces large amount of air pollution per joule of energy released.

14. Energy Return on Investment (EROEI) EROEI = Energy Obtained from the Fuel ------------------------------------------ Energy invested to obtain the fuel The larger the EROEI the more efficient (and more desirable : )

16. Finding the Right Energy Source Consider efficiency! Electric Hot Water Heater 99% efficient Does not take into account the coal used to supply the electricity Only 35% efficiency of fossil fuel to electricity

17. Gas Hot Water Heater 80% efficiency. Does not take into account delivering the natural gas. Even though an electric water has a higher direct efficiency than the natural gas the overall efficiency of the electric water heating system is lower..but not much less. Need to look at the overall system!!

18. Efficiency and Transportation 30% of our energy usage in the US is used for transportation. Uses gas, diesel and electricity. Contributes to greenhouse gas emissions. Public ground transportation more efficient than air.

19. Personal preference has an effect. SUVs, minivans, and pick up trucks account for ½ of the vehicle sales in the US. Hybrid electric vehicles account for only 2-3% of total sales.

21. Electricity is Convenient! Primary Sources of Energy: Coal, oil, and natural gas. Secondary Sources: Electricity (obtain it from a conversion of the primary source). Electricity is an energy carrier: can be moved and delivered in a usable form! 40% of energy used in the US generates electricity. Of that 40% only 13% is available for end users.

23. Electricity Generation Comes from primary sources: coal, natural gas, wind, or solar. “Clean” at the point of use (no pollutants are emitted). Pollution released at the point of production. Only 35% efficient (from fuel to electricity). Looking at the overall system, more efficient to burn wood or oil. The energy source that entails the fewest conversions from its original form to the end is the most efficient.

24. Efficiency of Electricity Generation Typical coal burning power plant has an efficiency of 35%. Combined Cycle: natural gas-fired power plant has two turbines and generations is more efficient. Natural gas is combusted and the combustion turns a gas turbine. Waste heat boils water which turns a turbine. May achieve efficiencies up to 60%.

25. Power plants have capacities- the maximum amount of electrical output. 500 megawatts per hour =s 12,000 MWh (500mw x 24 hours). Home electricity use is measured in kilowatt hours(kWh). 1 megawatt =s 1000 kWh Most power plants do not operate every day of the year. Capacity Factor: the fraction of time a plant is operating (.9).

27. Cogeneration(combined heat and power): use of a fuel to generate electricity and produce heat. Over 17,000 power plants in the US. In 2009 they generated 3.9 billion MWh. Coal is the backbone at 45%. Natural gas is 2 nd at 23%.

28. Fossil Fuels Provide Most of the World’s Energy Coal, oil, and natural gas. Come from organic matter that was formed 50-350 million years ago. Decomposers typically break down dead biomass. In places such as swamps, river deltas, and the ocean floor, a large amount of detritus material builds up in an anaerobic environment.

29. Decomposers cannot break this down. Heat and pressure turns it into high energy solids, liquids and gases.

30. Coal Largest coal reserves are found in the US, Russia, China, and India Peat: precursor to coal. Made up of partly decomposed organic material, including mosses. Four Types of of Coal: 1.Lignite 2.Subbituminous 3.Bituminous 4.Anthracite

32. Advantages: Energy dense. Plentiful. Easy to exploit with surface mining. Low cost to extract, not much technology needed. Once extracted, easy to handle, needs little refining. Easy to transport.

33. Disadvantages Released far more carbon dioxide into the atmosphere compared to natural gas or oil. Contains impurities, sulfur, which is released into the atmosphere when burned. Trace metals such as mercury, lead, and arsenic are also released. When burned these are released into the air or left behind in the ash. 1,450 coal mines in the US. 3-20% of what is burned is left as ash. Ash deposits must be maintained.

35. Petroleum Hydrocarbons, water, and sulfur liquid found in underground deposits. Being fluid is great! Remains of ocean-dwelling organisms phytoplankton that died 50m-150mya. Found in porous less dense sedimentary rocks. Once formed must be extracted and transported by a pipeline. Petroleum also contains natural gas. Crude Oil: liquid petroleum that is removed from the ground.

36. Crude oil can further refined into a variety of compounds including tar, asphalt, gas, diesel, and kerosene. Oil refineries boil oil and make it into different things. 150 oil refineries in the US. Oil sales measured in barrels..one barrel equals 160 Liters (42 gallons)

37. US uses petroleum more that any other fuel (816 million gallons per day) 22% of worldwide use. Mostly for transportation. Petrochemicals: plastics, lubricants, pharmaceuticals, and cleaning solvents. Top Petroleum Producing Countries: Saudi Arabia, Russia, US, Iran, China, Canada, and Mexico.

38. Advantages Easy to transport and use. Energy dense, cleaner than coal. Produces less carbon dioxide than coal. Less sulfur than coal(removed during refining).

40. Disadvantages Releases trace metals: mercury, lead, and arsenic. When extracted or transported there is the potential for oil leak or spill. 2010: Santa Barbara Spill 1989: Exxon Valdez tanker spill in Alaska 2005: Blowout of BP Deepwater Horizon oil well off of the coast of Louisiana (206 million gallons)

42. 85% of oil entering marine waterways came from runoff from land and rivers, airplanes, small boats and personal watercraft. Alaskan Pipeline 800 mile pipeline was constructed to transport oil. Inconclusive results of how it has effected wildlife. ANWR: pristine area (25 million gallons). Could harm wildlife.

45. Natural Gas With petroleum and also found separately. 80-95% methane (CH 4 ). 5-20% ethane, propane, and butane. Lighter than oil lies above the oil. Largest use: electricity usage and industry. Used to produce nitrogen fertilizer, cooking, heating, clothes dryers, and water heaters. Transported by pipeline, not viable to use for cars. Liquefied Petroleum Gas (LPG): less energy dense, used in place of natural gas. Can be transported.

47. Advantages Few impurities when burned. ½ homes in the US use natural gas for heating. Emits only 60% as much carbon dioxide as coal.

48. Disadvantages Emits methane (a greenhouse gas worse than carbon dioxide). Methane escapes when harvesting natural gas. When extracted have to drill and open rock: hydraulic fracturing “fracking”. Fracking: drilling with water, sand, and chemicals. Need large quantities of water and it releases chemicals that must be disposed.

49. Oil Sands and Liquefied Coal Oil Sands: slow flowing, viscous deposits bitumen mixed with sand, water, and clay. Bitumen: tar or pitch not capped with rock. Mining is energy intensive. Requires a lot of water. Lower efficiency, more CO 2 emitted.

50. Coal to Liquid (CTL) converting coal to a liquid fuel. Expensive. More greenhouse emissions (2x). Takes a lot of water. BAD for the environment.

51. Fossil Fuels are a Finite Resource Finite: will run out!! NON RENEWABLE!! NOT sustainable! Total energy use continues to increase. Energy use per person has leveled off. Energy Intensity: the energy use per unit of GDP, has been decreasing. We are using energy more efficiently but our overall energy usage has increased.

52. Hubbert Curve Projected the point at which world oil production would reach a maximum point at which we would run out. He predicted that oil extraction and use would increase steadily until roughly half the supply had been used up. Peak Oil: extraction and use begins to decline.

54. Future of Fossil Fuels If current global use patterns continue, we will run out of conventional oil supplies in less than 40 years. Natural gas will last slightly longer. Coal will last for at least 200 years, and maybe longer. Global warming has shifted the thought process concerning fossil fuel dependency.

55. Nuclear Energy: A Second Look Alternative energy source! Usually denied due to concerns about nuclear accidents, radioactivity, and possible weapon construction.

56. The Use of Fission in Nuclear Reactors Steam turns a turbine that turns a generator that generated electricity. Nuclear power uses a radioactive isotope, uranium 235 ( 235 U) as a fuel source. Fission: nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which splits into two or more parts. This releases addition neutrons and energy in the form of heat and propagates a chain reaction.

57. Uranium-235 is used. A neutron colliding with 235 U splits the uranium into smaller atoms, barium and krypton and results into 3 neutrons in motion (kinetic energy). By-products include radioactive waste that remains hazardous form may half-lives.

59. How it Works Fuel Rods: where the Uranium goes. Found in the core, or the center of the reactor. Heat produced nuclear fission is used to heat water which circulates in a loop. This turns a turbine, which turns a generator. Water slows down the neutrons so they can trigger the next reaction. Control Rods: absorb excess neutrons, slowing or stopping the fission reaction

60. Control rods are inserted routinely to prevent the fuel rods from becoming too hot and “melting down” which can cause a fire and a nuclear accident. Uranium needs to be mined. Mining uses fossil fuels and leaves mine tailings.

62. Advantages NO air pollution. 20% in the US (104 nuclear power plants) More in other countries. Higher energy density. Ample supply. Offers independence from imported oil.

63. Disadvantages Accidents: 1.1979: Three Mile Island, Pennsylvania. A cooling water valve had been closed the previous day. Lead to a lack of cooling around the core. Partial meltdown. Radioactive components were released. People were evacuated, lots of anxiety and fear. No documented increase in adverse health issues.

64. 2. Chernobyl, Ukraine 1986 Occurred during a test of the plant. Cooling system and control rods were removed. Resulted in a fire and explosion that damaged the plant beyond use. 31 died and many more later due to radiation exposure. Radiation was blown across much of Europe where it contaminated grass hence milk and beef. Resulted in increased cases of cancer(thyroid) and addition deaths.

65. Radioactive Waste No longer useful material but still emits radioactivity. Must be stored in special, highly secure locations. High Level Waste: old fuel rods. Low Level: rags tools and protective clothing. Uranium Mine Tailings: residue left over after the uranium is mined and enriched. All regulated by the government.

66. 235 U has a half life of 704 million years! Radiation can be measured with a variety of units. Becquerel (Bq): The rate at which a sample decays. 1Bq: 1 atom per second. Curie: 37 billion decays per second.

67. Power plants are currently required to store spent fuel rods at the plant itself. Spent fuel rods remain a threat to human health form 10 or more half-lives. A challenge! Cannot be burned, shot into space, dumped or buried. Has to be far away from humans, and secure from terrorists. Also cannot leak into the soil or groundwater. Yucca Mountain in Nevada a possibility?

69. Fusion Power Nuclear Fusion: the reaction that powers the sun and other stars. Occurs when lighter nuclei are forced together to produce heavier nuclei. Produces a great amount of heat. Only needs hydrogen, produces a small amount of radioactivity. Needs HIGH temps! So far the amount of energy needed to make this happen outweighs the output.