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Hydroelectric Power Jackie Richards 1 & Greg Samuels 2 1 Department of Chemical and Biochemical Engineering, 2 Department of Mechanical and Industrial Engineering, 52:133:001 Engineering Analysis of Alternative Energy Systems, http://wiki.uiowa.edu/display/greenergy/ ,
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Hydroelectric Power Jackie Richards1 & Greg Samuels2 1Department of Chemical and Biochemical Engineering, 2Department of Mechanical and Industrial Engineering, 52:133:001 Engineering Analysis of Alternative Energy Systems, http://wiki.uiowa.edu/display/greenergy/, The University of Iowa
History • BC: • 700 BC: Egyptian water wheel • BC-1000 AD: • 762 AD: Saxons use water mill • 1800’s: • 1824 AD: Scottish cotton mill uses water wheel, gearing achieves 9000 RPM! • 1880 AD: Michigan chair factory generates its own electricity using water turbine • 1881 AD: Niagara falls hydroelectricity powers street lamps • 1886 AD: 45 hydroelectric plants in U.S. and Canada • 1900’s: • 1907 AD: 15% of electricity generated in U.S. from hydropower • 1920 AD: 25% of electricity generated in U.S. from hydropower • 1929 AD: U.S.’s first pumped storage facility completed in Connecticut • 1937 AD: U.S.’s first federally regulated hydroelectric facility (Bonneville Dam) in Oregon • 1940 AD: 40% of electricity generated in U.S. from hydropower • 1974 AD: Fish and Wildlife Coordination Act ensures environmental considerations accounted for in federal hydroelectric facilities • 1983 AD: Largest hydroelectric power plant at this timefinished in Brazil at 12,600 MW • 2000’s: • 2008 AD: Hydroelectricity provides about 7 percent of U.S.’s electricity • 2011 AD: Three Gorges Dam (China) expected to produce 22,500 MW upon installation of additional generators
Hydrological Cycle • Large-body water motion is governed by the hydrological cycle. • As long as water is available, this cycle is renewable.
How a Hydroelectric Facility Works • Kinetic energy is converted to mechanical energy in turbine machinery and then converted to electrical energy and distributed using power lines.
Power Generation • Primary equation for determining hydroelectric facility electrical output: • Pactual = (ηtotal) ρ Q H g • ηtotal =combined efficiency of power generation including: • Water energy extraction efficiency • Mechanical efficiencies • Electrical efficiencies • ηtotal = 80-95%
Types of Hydroelectric Plants Impoundment • Most common type. • Uses a dam to store water in a reservoir (consistently reliable water source). • Water released from the reservoir flows through the system and turns the turbine. • Conventional flow: uses single-directional water flow.
Types of Hydroelectric Plants Diversion • Funnels a portion of river flow to a turbine system. • Complex system of pipes used to achieve flow diversion (no dams). • Conventional flow. • Less environmental impact because it is not blocked flow, just redirecting a portion of it. • Depends on river flow rate (better on a small scale).
Types of Hydroelectric Plants Pumped Storage • Utilizes upper and lower reservoirs and a reversible turbine to pump water in both directions (Unconventional flow). • Facility generates power during peak electrical hours (upper to lower), stores water during off hours (lower to upper). • Often used in conjunction with nuclear plants to help regulate electrical output.
Size Designations for Hydroelectric Plants • Large Hydropower • 30+ MW • Small Hydropower • 100 kW-30MW • Micro Hydropower • Less than 100 kW
Advantages of Hydroelectric Power • Hydroelectric plants can be constructed anywhere there is a water source; so it is a secure form of domestic energy. • It is a renewable source of power. • No pollution is created by the process. • There are no carbon dioxide emissions. • Cheap to maintain a facility (about ¢0.7 per kWh), which keeps cost of electricity low to consumers • Extremely efficient conversion of hydropower to electricity
Disadvantages of Hydroelectric Power • The initial construction of a plant requires a large capital cost and a lot of time ($1700-$2300/kW). • The pay back period is 10 or more years depending on the size of the plant. • Hydroelectric dams impact the migration and population of fish because they can become obstructed in the dam. • Power plants affect the temperature of the water; adversely affecting the native plants and animals in the water and on land. • The construction of dams and reservoirs may require the destruction of homes and relocation of people. • The use of power plants is dependent on water availability (climate). • Failure of large hydroelectric facilities (dam breach) results in catastrophic damage.
Hydroelectricity in the U.S. • Current U.S. hydroelectric generation amounts to about 95,000 MW, which is enough to power 28 million households.
Hydroelectricity in the U.S. • More than 75% of U.S.’s hydroelectric generation occurs in Montana, Oregon, Idaho, California, and Washington • Grand Coulee Dam, WA • Largest hydroelectric facility (and largest concrete structure) in U.S. • 6809 MW installed capacity
The Future of Hydroelectric Power in the U.S. • U.S. D.O.E. entire 50 states have ~30,000 MW of undeveloped potential hydroelectric capacity. • Large scale hydroelectric facilities (30+ MW) economically unattractive: • high capital costs • long pay back periods, and • extended construction times • Development of small scale (100 kW-30MW) and micro scale (less than 100 kW) hydropower facilities have promise in the future.
References • "International Energy Statistics." Energy Information Administration. http://tonto.eia.doe.gov/cfapps/ipdbproject/IEDIndex3.cfm. • "The History of Hydropower Development in the United States." U.S. Department of the Interior Bureau of Reclamation. Web. http://www.usbr.gov/power/edu/history.html. • "Hydropower Explained." Energy Information Administration. http://tonto.eia.doe.gov/energyexplained/index.cfm?page=hydropower_home. • "History of Hydropower." U.S. Department of Energy. http://www1.eere.energy.gov/windandhydro/hydro_history.html. • "History of Hydroelectric Power." University of Alaska at Fairbanks. http://ffden-2.phys.uaf.edu/104_spring2004.web.dir/Todd_Robyn/Page5.htm. • "Hydropower Resource Potential." U.S. Department of Energy. http://www1.eere.energy.gov/windandhydro/hydro_potential.html. • "Hydroelectric Power." U.S. Department of the Interior, Bureau of Reclamation, Power Resources Office. July 2005 Report. http://www.usbr.gov/power/edu/pamphlet.pdf. • "How Hydropower Works." U.S. Department of Energy http://www1.eere.energy.gov/windandhydro/hydro_how.html. • "How Hydropower Plants Work." How Stuff Works. http://science.howstuffworks.com/hydropower-plant1.htm. • "Hydropower." The Engineering Toolbox. http://www.engineeringtoolbox.com/hydropower-d_1359.html. • "Microhydropower." The Encyclopedia of Alternative Energy and Sustainable Living. http://www.daviddarling.info/encyclopedia/M/AE_microhydropower.html. • "Types of Hydropower Plants." U.S. Department of Energy.http://www1.eere.energy.gov/windandhydro/hydro_plant_types.html. • "Energy Producing Systems: Hydropower." Department of Natural Resources. http://www.dnr.mo.gov/teachers/energy/hydropower.pdf. • "Small Hydropower Design." Hydroventura. http://www.hydroventura.com/smallhydro_design.html. • "State Hydroelectric Statistics." Energy Information Administration. http://www.eia.doe.gov/cneaf/solar.renewables/page/hydroelec/hydroelec.html. • "2008 Annual Energy Review." Energy Information Administration. http://www.eia.doe.gov/emeu/aer/pdf/aer.pdf. • Perry, Z. "Advantages of Hydroelectric Power." http://hubpages.com/hub/advantages-hydroelectric-power. • "Hydroelectric Power and Water". USGS. http://ga.water.usgs.gov/edu/wuhy.html. • "An introduction to pumped storage." International Hydropower Association. http://www.hydropower.org/psd/articles/introduction.html. • "Ludington Pumped Storage." Consumers Energy. http://www.consumersenergy.com/content.aspx?id=1830&sid=109. • "Pumped storage hydroelectricity." Wikipedia. http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity.