Waterpower, power derived from the fall of water from a higher to a lower level, and extracted by means of waterwheels or hydraulic turbines (see Turbine). Waterpower is a natural resource, available wherever a sufficient volume of steady water flow exists. The development of waterpower today requires extensive construction, including storage lakes, dams, bypass canals, and the installation of large turbines and electric generating equipment. Because the development of hydroelectric power requires a large capital investment, it is often uneconomical for a region where coal or oil is cheap, even though the cost of fuel for a steam-powered generating plant is higher than the cost of running a hydroelectric plant. However, increasing environmental concerns are focusing attention on renewable energy sources.
Hydroelectric power generation was made more efficient by the establishment of the Federal Power Commission in 1920. Although additional hydroelectric plants were being built, the simultaneous development of larger and more cost-efficient steam-power plants made it obvious that only very large and costly hydroelectric installations could compete effectively, and that the federal government would have to assume a major share in their construction. Motivated by the search for the multiple use of water resources, including navigation, flood control, and irrigation, in addition to power production, the Tennessee Valley Authority, or TVA, started government participation in large-scale waterpower development in 1933.
Most major installations depend on a large water-storage reservoir upstream of the dam where water flow can be controlled and a nearly constant water level can be assured. In contrast to storage-type plants, which depend on the ...