Hydropower Facts
Hydropower is the renewable energy source that produces the most electricity in the United States. It accounted for 6% of total U.S. electricity generation and 67% of generation from renewables in 2008.
Source: US Energy Information Administration
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Electricity from Hydropower
The movement of water as it flows downstream creates kinetic energy that can be converted into electricity. A hydroelectric power plant converts this energy into electricity by forcing water, often held at a dam, through a hydraulic turbine that is connected to a generator. The water exits the turbine and is returned to a stream or riverbed below the dam. Hydropower is mostly dependent upon… Learn more
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Often, water at the bottom of the lake created by a dam is inhospitable to fish because it is much colder and oxygen-poor compared with water at the top. When this colder, oxygen-poor water is released into the river, it can kill fish living downstream that are accustomed to warmer, oxygen-rich water… Learn more
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In the United States, hydropower generates nearly nine percent of the total electricity supply. In the Pacific Northwest alone, hydropower provides about two-thirds of the region’s electricity supply.2 Currently, facilities in the U.S. can generate enough hydropower to supply electricity to 28 million households, which is equivalent to about 500 million barrels of oil. In 2003, total hydropower capacity in the United States was 96,000 MW.3 The undeveloped capacity for the United States is approximately 30,000 MW.
Source: US Environmental Protection Agency
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Over half of U.S. hydroelectric capacity for electricity generation is concentrated in three States: Washington, California, and Oregon. Approximately 31% of the total U.S. hydropower is generated in Washington, the location of the Nation’s largest hydroelectric facility — the Grand Coulee Dam.
Source: US Energy Information Administration
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Most dams in the United States were built mainly for flood control and supply of water for cities and irrigation. A small number of dams were built specifically for hydropower generation. While hydropower (hydro-electric) generators do not directly produce emissions of air pollutants, hydropower dams, reservoirs, and the operation of generators can have environmental impacts… Learn more
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Tidal power is more predictable than wind energy and solar power. A large enough tidal range — 10 feet — is needed to produce tidal energy economically.
Source: US Energy Information Administration
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Waves are caused by the wind blowing over the surface of the ocean. There is tremendous energy in the ocean waves. It’s estimated that the total potential off the coast of the United States is 252 billion kilowatthours a year, about 7% of the United States’ electricity consumption in 2008. The west coasts of the United States and Europe and the coasts of Japan and New Zealand are good sites for harnessing wave energy.
Source: US Energy Information Administration
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Ocean Thermal Energy Conversion
Hawaii has experimented with OTEC since the 1970s. There is no large-scale operation of OTEC today, mainly because there are many challenges. The OTEC systems are not very energy efficient. Pumping water is a major engineering challenge… Learn more
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