Hydropower
Hydropower is our most mature and
largest source of renewable power, pro-
ducing about 10 percent of the nation’s
electricity. Existing hydropower capacity
is about 77,000 megawatts (MW). Hydro-
power plants convert the energy in flowing
water into electricity. The most common
form of hydropower uses a dam on a river
to retain a large reservoir of water. Water is
released through turbines to generate
power. “Run of the river” systems, how-
ever, divert water from the river and
direct it through a pipeline to a turbine.