Hydroelectric Power

Hydroelectric power — generating electricity from moving water — is the world's largest source of renewable electricity, producing approximately 16% of global electricity from 3,700 GW of installed capacity. The principle: water's potential energy (height above a turbine) is converted to kinetic energy, driving turbines connected to generators. The first large-scale hydroelectric plant was the Adams Power Plant at Niagara Falls (1895, Tesla/Westinghouse AC system). The Three Gorges Dam (China, completed 2003) is the world's largest power station by installed capacity — 22,500 MW, generating more electricity than 14 nuclear plants and displacing 1.4 million people in its reservoir. The Itaipu Dam (Brazil/Paraguay) is the largest by annual energy production. Hydroelectric dams provide flood control, water storage, and navigation improvements but fragment rivers, block fish migration (salmon runs declined 90%+ on dammed rivers), and displace communities.