Three Gorges Dam

The Three Gorges Dam on China's Yangtze River has 34 generators with a combined capacity of 22,500 megawatts, the biggest of any power station on Earth. The dam is about 2.3 km long and also helps control floods.

Capacity is not the same as annual output. Itaipu Dam, for example, has out-produced Three Gorges in some years for the energy it actually generated.

Context

The installed capacity of 22,500 megawatts is the sum of 32 main generators of 700 megawatts each and two smaller ones of 50 megawatts. Installed capacity is the maximum power the plant could produce when running flat out, not what it actually generates over a year.

The dam is about 2.3 kilometres long and around 180 metres high, and it created a reservoir that stretches hundreds of kilometres up the Yangtze. Its purposes include electricity, flood control and improved river navigation, with a large ship lift and locks for vessels. Construction began in the 1990s, and the last generators were commissioned around 2012.

The project was controversial. Well over a million people were relocated, and critics raised concerns about sediment, ecology and landslides, while supporters point to reduced flood risk and coal not burned. Annual energy production depends on rainfall and river flow, and some other large plants, for example Itaipu on the Brazil–Paraguay border, have in some earlier years produced more energy in a year than Three Gorges, even with a smaller capacity.