Renewable sources of energy refer to energy sources that can be replenished over a period of time. These include energy from the sun, wind, water, geothermal and biomass. The energy generated from these sources is used provide electricity, power vehicles and machinery; provide lighting, heating and cooling. Availability and cost effectiveness are what makes these renewable sources to vary in the United States . Renewable energy sources in the United States include biomass power, hydropower, geothermal power, solar power, and wind power.
Hydropower is generated from water which produces hydroelectricity. Water is the most common renewable source of energy in the United States. Major hydroelectric dams are found in the Northwest, Colorado River, and the Tennessee Valley. Wind power has become an increasingly attractive source of renewable energy in the US. It increases rapidly with the wind speed therefore location of windmills in areas having strong winds is critical. Currently Wind power supplies about 1% of United States electricity needs, though capacity is expanding rapidly thus cannot supply the US sufficiently.
Solar power provides heat, light, electricity and cooling. It provides less than 1% of US energy needs though it is expected to increase due to the development of new technologies. On the other hand geothermal power uses naturally heat producing sources beneath the earth to produce energy. Currently three technologies are used in the US; direct-use systems, use of deep reservoirs to generate electricity, and geothermal heat pumps . Despite being efficient and environment friendly, it currently meets less than 1% of US energy needs.
Lastly Biomass power is obtained from plants and their derivatives. It is the second most producing source of energy in the US and an important part of waste management infrastructure. Since bio-power is obtained from plants, it can be produced almost everywhere in the US.
References
Associates, National Economic Research. Energy consumption and gross national product in the United States:. New York: oxford, 1971.
Nye, David E. Consuming Power: A Social History of American Energies. Massachussetts: MIT Press, 1999.