Itaipu Dam

The Itaipu Dam (Guarani: Itaipu, Portuguese: Itaipu, Spanish: Itaipú;, ) 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 Guaraní language, Itaipu means "the sounding stone".

The dam is the largest operating hydroelectric facility in terms of annual energy generation, generating 94.7 TWh in 2008 and 91.6 TWh in 2009, while the annual energy generation of the Three Gorges Dam was 80.8 TWh in 2008 and 79.4 TWh in 2009. The dam's 14,000 MW installed capacity is second to the Three Gorges Dam's 22,500 MW, though. 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. The project ranges from Foz do Iguaçu, in Brazil, and Ciudad del Este in Paraguay, in the south to Guaíra and Salto del Guairá 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.

Of the twenty generator units currently installed, ten generate at 50 Hz for Paraguay and ten generate at 60 Hz for Brazil. Since the output capacity of the Paraguayan generators far exceeds the load in Paraguay, two 600 kV HVDC lines, each approximately 800 km long, carry the majority of the Paraguayan energy to São Paulo where the terminal equipment converts the power to 60 Hz.