Energy Resources and Consumption

1. Energy Resources and Consumption

2. Areas Tested • Energy Concepts • Energy, forms, power units, conversions, and laws of thermodynamics • Energy Consumption • History – Industrial Revolution, exponential growth, and energy crisis • Present global energy use • Future energy needs • Fossil Fuel Resources and Use – formation of coal, oil, and natural gas, extraction/purification methods, world reserves and global demand, synfuels, and environmental advantages/disadvantages of sources

3. Nuclear Energy – nuclear fission process, nuclear fuel, electricity production, nuclear reactor types, environmental advantages/disadvantages, safety issues, radiation and human health, radioactive wastes, and nuclear fusion • Hydroelectric Power - dams, flood control, salmon, silting, and other impacts • Energy Conservation - energy efficiency, CAFE standards, hybrid electric vehicles, and mass transit • Renewable Energy - solar energy, solar electricity, hydrogen fuel cells, biomass, wind energy, small-scale hydroelectric, ocean waves and tidal energy, geothermal, amd environmental advantages/disadvantages

4. Energy Concepts • See packet for energy forms and units • See free-response for and example of a conversion problem • MW to kW to kWh/yr • First Law of Thermodynamics • Energy can not be created or destroyed • Second Law of Thermodynamics • When energy is converted from one form to another a less useful form results • Most of the energy lost is lost as heat and is considered low-quality energy

5. Energy Consumption • History • wood was the predominant form of energy until the Industrial Revolution • During the Industrial Revolution coal became the primary source • 20th century has seen petroleum overtake coal but natural gas and coal has seen an increase in the later half of the 20th century

6. Present Global Use • US was self-sufficient until the late 1950s • Industrial, Transportation, residential and commercial (greatest to least amount used) • US accounts for 25% of the world consumption of petroleum (tar, oil, and natural gas) • See comparison chart of production vs consumption • Future Energy Needs • The forecast is a continued reliance of oil, natural gas and coal • Viable resources are clean coal, methane hydrates, oil shale, and tar sands

7. Clean coal • This technology refers to the process that reduces the negative environmental impact of burning coal • The coal is washed and the sulfur dioxide and carbon dioxide gas is captured (see picture) • Other forms of clean-coal technology has to do with natural gas or microbial fuel cells which are charged from biomass or sewage • Methane Hydrates • Methane locked in ice – found in permafrost and deep beneath the ocean floor • Type of natural gas can create a greater amount of carbon dioxide a greenhouse gas

8. Oil Shale • Contains an organic material called kerogen that converts to oil in the absence of air • Net energy considered moderate due to the energy needed to put into extracting it • Huge negative environmental impact due to surface mining • Can be mined underground through heating it in the ground and extracting the oil and gases though this can affect aquifers • Tar Sands • Contain a semisolid form of oil called BITUMEN • Similar issues with oil shale – oil in tar sands represents two-thirds of the world’s total oil reserves

9. Fossil Fuel Resources and Use • Coal • Produces by ancient organic matter (286 million year old) under high temperature and pressure • Lignite – softest and lowest heat content • Subbituminous – lower sulfur content leading to cleaner burning fuel • Bituminous - high sulfur content and most plentiful in the US – use to make electricity • Anthracite – hard and high heat component and relatively low sulfur content – home heating least amount

10. Oil • Fossil fuel produced by the decomposition of deeply buried organic material under high temperature and pressures for millions of years • Natural Gas • Known as methane produced by decomposition of organic matter under high temp and pressure usually found along with oil reserves • Can be liquefied mainly for easy worldwide distribution

11. Extraction-Purification Methods • Coal – largest in China • Surface mining and underground mining • Removal of foreign material, screening for size, crushing, and washing to remove contaminants • Oil – Middle East • Expensive machinery used to drill a well…initially high pressure and later pumped • Sent to a refinery to be ‘cracked’ which is where it is separated by its boiling points (see picture) • Natural Gas – Russia and Kazakhstan • Flows from wells under its own pressure and is collected by small pipelines that feed into the large gas transmission pipelines • Removal of water and condensates

12. Synfuels • Liquid fuel synthesized from a non petroleum source such as coal (shale oil and synthetic natural gas) • Pros • Easily transported through pipelines • Produces less air pollution • Large supply of raw materials to meet current demands for hundreds of years • Can produce gasoline, kerosene, or diesel directly without cracking or refining • Cons • Low net energy yield and use of energy to produce most • Plants are expensive and increase depletion of coal • More expensive product than petroleum products

13. Nuclear Energy • Nuclear fission – an atom splits into two or more smaller nuclei along with by-product particles (neutrons, photons, gamma rays, and beta and alpha particles) • If controlled – heat produced makes steam that turns generators that produce electricity • If NOT controlled – nuclear explosion

14. Nuclear Fuel • U-235 – called enriched uranium, nuclear weapons contain 85% or more, nuclear power plants contain about 3% • U-238 – most common isotope, hit with neutrons to decay into Pu-239, most depleted uranium • Pu-239 – 1/3 of energy produced in a typical commercial plant, amount of Pu-239 produced is regulated and control rods have to be changed frequently due to the build up of Pu-239 and Pu-240 – can be used for nuclear weapons

15. The US produces the most nuclear energy but it only makes up 19% of the energy we consume • France produces the highest percentage of what it consumes at 78%

16. Types of reactors • Light-water, heavy-water, and graphite-moderated • Common features • The core contains up to 50,000 fuel rods each stacked with many fuel pellets • Uranium oxide is the fuel: 97% U-238 and 3% U-235 • Control rods move in and out to absorb neutrons and slow down the reaction • Neutron moderator is a medium that reduces the velocity of fast neutrons making them capable of sustaining a nuclear chain reaction (water, graphite – produces plutonium for weapons, or deuterium oxide – heavy water) • Coolant removes heat and produces steam to generate electricity • See the Price-Anderson Nuclear Indemnity Act - 1957

17. Health Risks • Premature death per year • Nuclear – 6,000 • Coal – 65,000 • Genetic defects/damage • Nuclear – 4,000 • Coal – 200,000

18. Nuclear Fusion • Two or more atomic nuclei joining together to form a single heavier nucleus • Not yet controlled enough for use as nuclear power

19. Hydroelectric Power • Supplies 10% of the electricity in the US and 3% worldwide • Flood control • Channelization • Dams • Identify and manage flood-prone areas • Levees or floodwalls • Preserve wetlands • Salmon • Migratory runs blocked and many spawning and rearing habitats are destroyed • Fish passage facilities and fish ladders to help juvenile and adult fish migrate over or around dams

20. Other impacts • Disease – breeding grounds for mosquitoes, snails and flies • Displacement – behind dams destroy rich croplands and displace people • Effects on watershed – downstream deprived of nutrient-rich silt • Impact on wildlife – migration and spawning cycles • Silting – forms behind the dam • Water loss – evaporation and seepage

21. CAFE standards • Corporate Average Fuel Economy • The average fuel economies of a manufacturer’s fleet of passenger cars or light trucks • Standards have not improved since 1996 • Could be expanded to include • Transition to a hybrid technology • Performance-based tax credits • Optimizing transmission improvements

22. Hybrids • Parallel hybrid – gas engine and electric engine work at the same time – Honda Insight • Parallel-split hybrid – can change back and forth with the engine charging the batteries – Toyota Prius • Plug-in hybrid – plug in each time and used first, when used up changes to fuel tank

23. Renewable Energy • Solar Energy • Hydrogen Fuel Cells • Biomass • Wind Energy • Small scale Hydroelectric • Ocean Waves and Tidal Energy • Geothermal