Geol110 chapter 14 PowerPoint

Energy ResourcesAlternative Sources: 

Energy Resources Alternative Sources

Figure 14.33: 

Figure 14.33

Figure 14.1 World energy production by source, 1999: 

Figure 14.1 World energy production by source, 1999

Table 14.1: 

Table 14.1

Figure 14.2 Regional variations in energy consumption in the United States. 1999: 

Figure 14.2 Regional variations in energy consumption in the United States. 1999

Figure 14.3 Actual and projected vehicle ownership for selected countries.: 

Figure 14.3 Actual and projected vehicle ownership for selected countries.

Figure 14.4 World energy consumption, historic and projected to 2020. projected increase from 1999 to 2020 is about 60%: 

Figure 14.4 World energy consumption, historic and projected to 2020. projected increase from 1999 to 2020 is about 60%

Nuclear Power - Fission: 

Nuclear Power - Fission Fission – splitting apart the atom releases energy Currently commercially feasible Uranium-235 fuels most fission reactors A controlled chain reaction occurs with continuous and moderate release of energy The energy release heats water within the core of a reactor This heat is transferred through heat exchangers to outer loops where steam generation is possible for generating power or propulsion

Figure 14.5 Nuclear fission and chain reaction involving uranium-235 (schematic. Neutron capture by uranium-235 causes fission into two smaller nuclei plus additional neutrons, other subatomic particles, and energy. Released neutrons, in turn, cause fission in other uranium-235 nuclei. As U-235 nuclei are used up, reaction rate slows; eventually fresh fuel must replace “spent” fuel.: 

Figure 14.5 Nuclear fission and chain reaction involving uranium-235 (schematic. Neutron capture by uranium-235 causes fission into two smaller nuclei plus additional neutrons, other subatomic particles, and energy. Released neutrons, in turn, cause fission in other uranium-235 nuclei. As U-235 nuclei are used up, reaction rate slows; eventually fresh fuel must replace “spent” fuel.

Figure 14.6 Schematic diagram of conventional nuclear fission reactor. Heat is generated by chain reaction; withdrawing or inserting control rods between fuel elements varies rate of reaction, and thus rate of release of heat energy. Cooling water also serves to extract heat for use. Heat is transferred to power loop via heat exchanger, so the cooling water, which may contain radioactive contaminants, is isolated from the power generating equipment.: 

Figure 14.6 Schematic diagram of conventional nuclear fission reactor. Heat is generated by chain reaction; withdrawing or inserting control rods between fuel elements varies rate of reaction, and thus rate of release of heat energy. Cooling water also serves to extract heat for use. Heat is transferred to power loop via heat exchanger, so the cooling water, which may contain radioactive contaminants, is isolated from the power generating equipment.

Table 14.2: 

Table 14.2

Geology of Uranium: 

Geology of Uranium 95% of uranium found in sedimentary (or metasedimentary) rocks Generally found in sandstones Uranium is weathered from other rocks and deposited by migrating ground water

Figure 14.7 The nuclear fuel cycle, as it currently operates and as it would function with fuel reprocessing.: 

Figure 14.7 The nuclear fuel cycle, as it currently operates and as it would function with fuel reprocessing.

Extending the Nuclear Fuel Supply: 

Extending the Nuclear Fuel Supply Uranium-235 is not the only fuel useful for fission-reactors It is the most plentiful naturally occurring one Uranium-238 can absorb a neutron and converts to plutonium-239 and is fissionable U-238 makes up 99.3% of natural uranium Used for over 90% of reactor grade enriched uranium Breeder reactor can maximize the production of other radioactive fuels Expensive and complex

Figure 14.9 Locations of U.S. uranium reserves.: 

Figure 14.9 Locations of U.S. uranium reserves.

Concerns Related Nuclear Reactor Safety: 

Concerns Related Nuclear Reactor Safety Nuclear reactor safety is a serious undertaking Controlled release of very minor amounts of radiation occur Major concerns are with accidents and sabotage Loss of coolant in the core could produce a core meltdown This event could allow the fuel and core materials to melt into an unmanageable mass and then migrate out of the containment structure Could result in a catastrophic release of radiation into the environment Reactors must be located away from active faults

Figure 14.8 Three Mile Island near Harrisburg, Pennsylvania; damaged reactor remains shut down, while others are still operative.: 

Figure 14.8 Three Mile Island near Harrisburg, Pennsylvania; damaged reactor remains shut down, while others are still operative.

Concerns Related to Fuel Handling: 

Concerns Related to Fuel Handling Mining and processing of uranium ore is a radioactive hazard Miners are exposed to higher levels of radioactivity than the general population Tailings piles are exposed to weather and the uranium is mobilized into the environment Plutonium is both radioactive and chemically toxic Easy to convert into nuclear weapons material Uranium (enriched) is serious security problem

Radioactive Wastes: 

Radioactive Wastes Energy produced by nuclear fission produces radioactive wastes Difficult to treat No long-term, permanent storage or disposal sites in operation Nuclear power plants are decommissioned once operations cease Expensive to decommission these plants Abundant radioactive contaminated material associated with these plants that must be permanently stored somewhere and safely

Figure 14.10 Age distribution of nuclear reactors worldwide, February 2003. Few face decommissioning yet, but many may be in the next decade or two.: 

Figure 14.10 Age distribution of nuclear reactors worldwide, February 2003. Few face decommissioning yet, but many may be in the next decade or two.

Figure 14.11 Distribution of U.S. nuclear power plants. In December 2002, there were 104 operable plants, and three for which construction permits had been granted. (Due to space limitations, symbols do not represent actual locations; the number of plants in each state is accurate.: 

Figure 14.11 Distribution of U.S. nuclear power plants. In December 2002, there were 104 operable plants, and three for which construction permits had been granted. (Due to space limitations, symbols do not represent actual locations; the number of plants in each state is accurate.

Figure 14.12: 

Figure 14.12 Percentage of electricity generated by nuclear fission varies greatly by country, and not simply in proportion to numbers of reactors; where electricity consumption is moderate, a few reactors can account for a large share.

Nuclear Power - Fusion: 

Nuclear Power - Fusion Sun is a gigantic fusion reactor Fusion is a cleaner form nuclear power than fission Fusion – involves combining smaller nuclei to form larger ones Can produces abundant energy Hydrogen is plentiful and is the raw material required Fusion difficult to achieve given current technology Theoretical – not yet economically attained

Figure 14.13 Schematic diagram of one nuclear fusion reaction. Other variants are possible.: 

Figure 14.13 Schematic diagram of one nuclear fusion reaction. Other variants are possible.

Solar Energy: 

Solar Energy Abundant solar energy reaches the earths surface Solar energy is free, clean, and a renewable resource Limitations are latitude and climate Solar Heating Passive solar heating Active solar heating Solar Electricity Photovoltaic cells

Distribution of solar energy over the continental United States. Maximum insolation occurs over the southwestern region. Numbers are watts per square meter; boundaries between zones connect points of equal insolation. : 

Distribution of solar energy over the continental United States. Maximum insolation occurs over the southwestern region. Numbers are watts per square meter; boundaries between zones connect points of equal insolation.

Figure 14.15 (A) Basics of passive-solar heating with water or structural materials as thermal reservoir: Sunlight streams into greenhouse with glass roof and walls, heat is stored for nights and cloudy days.: 

Figure 14.15 (A) Basics of passive-solar heating with water or structural materials as thermal reservoir: Sunlight streams into greenhouse with glass roof and walls, heat is stored for nights and cloudy days.

Figure 14.15 (B) Design features of home and landscaping can optimize use of sun in colder weather, provide protection from it in summer.: 

Figure 14.15 (B) Design features of home and landscaping can optimize use of sun in colder weather, provide protection from it in summer.

Figure 14.15 (C)A common type of active-solar heating system with a pump to circulate the water between the collector and the heat exchange/storage tank.: 

Figure 14.15 (C)A common type of active-solar heating system with a pump to circulate the water between the collector and the heat exchange/storage tank.

Figure 14.16 Schematic diagram of a photovoltaic (solar) cell for the generation of electricity.: 

Figure 14.16 Schematic diagram of a photovoltaic (solar) cell for the generation of electricity.

Figures 14.17 (A) Solar electricity is very useful in remote areas. High in the mountains of Denali National Park, at the base camp that is the takeoff point for expeditions to climb Denali (Mount McKinley), solar cells (right) power vital communications equipment.: 

Figures 14.17 (A) Solar electricity is very useful in remote areas. High in the mountains of Denali National Park, at the base camp that is the takeoff point for expeditions to climb Denali (Mount McKinley), solar cells (right) power vital communications equipment.

Figures 14.18 Some possible schemes for storing the energy of solar-generated electricity. (A) Use solar electricity to break up water molecules into hydrogen and oxygen; recombine them later (burn the hydrogen) to release energy. (B) Use solar energy to pump water up in elevation; where the energy is needed, let the water fall back and use it to generate hydropower.: 

Figures 14.18 Some possible schemes for storing the energy of solar-generated electricity. (A) Use solar electricity to break up water molecules into hydrogen and oxygen; recombine them later (burn the hydrogen) to release energy. (B) Use solar energy to pump water up in elevation; where the energy is needed, let the water fall back and use it to generate hydropower.

Geothermal Power: 

Geothermal Power Interior of the earth is very hot Abundant source of heat and hot water Magma rising into the crust bring abundant heat up into the crust as geothermal energy Heat escaping from the magma heats water and the water convectively circulates

Figure 14.19 Geothermal energy is utilized by tapping circulating warmed ground water.: 

Figure 14.19 Geothermal energy is utilized by tapping circulating warmed ground water.

Figure 14.20: 

Figure 14.20 One of the many thermal features in Yellowstone National Park. Lone Star Geyser. Structure is built by deposition of dissolved minerals.

Geothermal Power: 

Geothermal Power Applications of Geothermal Energy Circulating geothermal water through buildings to heat them Use the hot geothermal water to raise the temperature of other water to reduce cost of heating that water Environmental Considerations Some locations have sulfur gases in the geothermal fluids Other chemical (caustic) elements may be present that can clog geothermal circulation systems

Figure 14.21 Geothermal power plants worldwide: 

Figure 14.21 Geothermal power plants worldwide

Figure 14.22: 

Figure 14.22 The Geysers geothermal power complex, California is the largest such facility in the world. Hydrothermally altered rocks expose in foreground

Limitations on Geothermal Power: 

Limitations on Geothermal Power First, most geothermal fields have limited life times and taper off Second, geothermal fields are stationary – not mobile Third, not many geothermal sites are suitable for energy production

Figure 14.23: 

Figure 14.23 Mammoth Terraces in Yellowstone National Park have been built by centuries of deposition of minerals dissolved in circulating geothermal waters that have seeped out at the surface

Alternative Geothermal Sources: 

Alternative Geothermal Sources Many areas away from plate boundaries have high geothermal gradients These areas contain hot-dry-rock type geothermal resources Deep drilling into such rocks may produce appreciable amounts of geothermal energy

Figure 14.24: 

Figure 14.24 The area east of the Rocky Mountains has a geothermal gradient and surface heat flow typical of world average continental curst; selected areas west of the Rockies have more energy potential.

Hydropower: 

Hydropower Falling or flowing water has long been used to produce energy for humans Hydroelectric power produces less than 5% of U.S. energy requirement Typically, a stream is dammed and the discharge is regulated to produce electricity Hydropower is clean and non-polluting Hydropower is renewable as long as streams have water flowing in them

Figure 14.25 Glen Canyon Dam hydroelectric project. In dry surroundings such as these, evaporation losses from reservoirs are high and can exacerbate regional water-supply problems: 

Figure 14.25 Glen Canyon Dam hydroelectric project. In dry surroundings such as these, evaporation losses from reservoirs are high and can exacerbate regional water-supply problems

Figure 14.26 water use for hydropower generation in the United States is concentrated where stream flow is plentiful.: 

Figure 14.26 water use for hydropower generation in the United States is concentrated where stream flow is plentiful.

Figure 14.27 Hydropower is currently the dominant renewable energy source in the United States, although renewable sources still provide a relatively small proportion of energy used.: 

Figure 14.27 Hydropower is currently the dominant renewable energy source in the United States, although renewable sources still provide a relatively small proportion of energy used.

Limitations on Hydropower Development: 

Limitations on Hydropower Development Reservoirs tend to: Silt up Increase surface area exposed to evaporation Destroy habitats Encourage earthquakes Expensive to build Reservoirs are stationary power sources

Tidal Power: 

Tidal Power Limited energy production possible Not enough difference in high-tide versus low-tide displacement of water (only about 1 meter difference) Most economic potential requires about 5 meters difference

Figure 14.28: 

Figure 14.28 Tidal-power Generation uses flowing water to generate electricity, as with conventional hydropowere.

Figure 14.29 Given the thermal and other requirements of OTEC, tropical islands are likely to be the first sites for its development.: 

Figure 14.29 Given the thermal and other requirements of OTEC, tropical islands are likely to be the first sites for its development.

Wind Energy: 

Wind Energy Clean and renewable energy resource Many technological improvements have increased the energy production from windmills Areas of best wind generation potential tend to be far from population centers that would benefit from them “Wind Farms” are large scale operations producing about 1 megawatt per windmill Abundant small scale windmills involve small wind turbines lifting water on a ranch or farm

Figure 14.30 Numbers indicate the percentage of 1990 electricity demand that the corresponding region could theoretically supply with full utilization of wind-power technology.: 

Figure 14.30 Numbers indicate the percentage of 1990 electricity demand that the corresponding region could theoretically supply with full utilization of wind-power technology.

Figure 14.31 Wind-turbine array near Palm Springs, California. Different elements of the array can take advantage of various velocities of wind. Some of the smaller turbines turn even in light wind, while the larger turbines require stronger winds to drive them.: 

Figure 14.31 Wind-turbine array near Palm Springs, California. Different elements of the array can take advantage of various velocities of wind. Some of the smaller turbines turn even in light wind, while the larger turbines require stronger winds to drive them.

Figure 14.32 U.S. wind power installed capacity, 1981-2002: 

Figure 14.32 U.S. wind power installed capacity, 1981-2002

Biomass: 

Biomass Biomass energy uses discarded waste material that is burned as a fuel to produce energy Biomass fuels include wood, paper, crop waste, and other combustible waste Alcohol, as a fuel, is produced from grains, such as corn Mixed with gasoline to form gasohol Qualifies as a renewable resource