1. Three Gorges Dam, China (22,500 MW): The Three Gorges Dam is a hydroelectric dam that spans the Yangtze River by the town of Sandouping, located in the Yiling District of Yichang, in Hubei province, China. It is the world’s largest electricity-generating plant of any kind.
The dam body was completed in 2006. Except for a ship lift, the originally planned components of the project were completed on October 30, 2008, when the 26th generator in the shore plant began commercial operation. Each generator has a capacity of 700 MW.
2. Itaipu, Brazil/Paraguay (12,600 MW): The Itaipu Dam is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The name “Itaipu” was taken from an isle that existed near the construction site. In the Guarani language, Itaipu means “the sound of a stone”. The American composer Philip Glass has also written a symphonic cantata named Itaipu, in honour of the structure.
The dam is the largest operating hydroelectric facility in terms of annual generating capacity, generating 94.7 TWh in 2008 and 91.6 TWh in 2009, while the annual generating capacity of the Three Gorges Dam was 80.8 TWh in 2008 and 79.4 TWh in 2009. It is a binational undertaking run by Brazil and Paraguay at the Paraná River on the border section between the two countries, 15 km (9.3 mi) north of the Friendship Bridge.
3. Guri, Venezuela (10,200 MW): The Guri Dam is a large dam in Bolívar State, Venezuela on the Caroni River. It is one of the largest dams in the world. Its official name is Central Hidroeléctrica Simón Bolívar (previously named Central Hidroeléctrica Raúl Leoni from 1978 to 2000). It is 1300 meters long and 162 m high. Construction began in 1963; the first part concluded in 1978 and the second in 1986.
The dam has long been the focus of much controversy, because the lake it created forever destroyed thousands of square miles of forest that was renowned for its biodiversity and rare wildlife, including the only place where the recently-discovered Carrizal Seedeater (a finch-like tanager) was ever found.
4. Tucurui, Brazil (8,370 MW): The Tucuruí Dam is a concrete gravity dam on the Tocantins River located on the Tucuruí County in Brazil. The main purpose of the dam is hydroelectric power production and navigation. It is the first large-scale hydroelectric project in the Brazilian Amazon rainforest. The maximum capacity of the 25-unit plant is 8,370 MW. Phase I construction began in 1975 and ended in 1984 while Phase II began in 1998 and is ongoing from delays.
5. Grand Coulee, US (6,809 MW): Grand Coulee Dam is a hydroelectric gravity dam on the Columbia River in the U.S. state of Washington. It is the largest electric power-producing facility and the largest concrete structure in the United States. It is the fifth largest producer of hydroelectricity in the world, as of the year 2008.
The reservoir is called Franklin Delano Roosevelt Lake, named after the United States President who presided over the completion of the dam.