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 Guaran language, Itaipu means “the sounding stone”.
The dam is the largest operating hydroelectric facility in terms of annual energy generation, generating 98.3 TWh in 2012 and 98.6 TWh in 2013, while the annual energy generation of the Three Gorges Dam was 98.1 TWh in 2012 and 83.7 TWh in 2013. It is a binational undertaking run by Brazil and Paraguay at the Paraná River on the border section between the two countries, 9.3 mi north of the Friendship Bridge. The project ranges from Foz do Iguacu, in Brazil, and Ciudad del Este in Paraguay, in the south to Guaira and Salto del Guaira in the north.
The installed generation capacity of the plant is 14 GW, with 20 generating units providing 700 MW each with a hydraulic design head of 118 m. In 2008 the plant generated a record 94.68 TWh, supplying 90% of the electricity consumed by Paraguay and 19% of that consumed by Brazil. The total length of the dam is 7235 m. The crest elevation is 225 m. Itaipu is actually four dams joined together – from the far left, an earth fill dam, a rock fill dam, a concrete buttress main dam, and a concrete wing dam to the right. The spillway has a length of 483 m. The maximum flow of Itaipu’s fourteen segmented spillways is 62.2 thousand cubic metres per second, into three skislope formed canals. It is equivalent to 40 times the average flow of the nearby natural Iguacu Falls. The flow of two generators (700 m3/s each) is roughly equivalent to the average flow of the Iguacu Falls (1500 m3/s).