Three Gorges 

The Three Gorges Dam is the world’s largest hydroelectric power station by total capacity, which will be 22,500 MW.It will have 34 generators: 32 will be main generators, each with a capacity of 700 MW, and the other two will be plant power generators, each with capacity of 50 MW. Among those 32 main generators, 14 are installed in the north side of the dam, 12 in the south side, and the remaining six in the underground power plant in the mountain south of the dam. After completion, the expected annual electricity generation will be over 100 TWh, 18% more than the originally predicted 84.7 TWh, since six generators were added in 2002.

Itaipu 14,750 MW

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 main dam, and a concrete wing dam to the right.

• The maximum flow of Itaipu’s fourteen segmented spillways is 62.2 thousand cubic metres/sec It is equivalent to 40 times the average flow of the  Iguacu Falls.
• The flow of two generators (700 m³·s−1 each) is roughly equivalent to the average flow of the Falls (1500 m³·s−1).
• If Brazil were to use  Thermal Power Generation to produce the electric power of Itaipu, 434,000 barrels (69,000 m3) of  petroleum would have to be burned every day.
• The dam is 196 metres high, equivalent to a 65-story building.
• Though it is the seventh largest reservoir in size in Brazil, the Itaipu’s reserviorr has the best relation between electricity production and flooded area. For the 14,000 MW installed power, 1350 square kilometres were flooded. The reservoirs for the hydroelectric power plants of Sobradinho, Tucuruí, Porto Primavera, Balbina, Serra da Mesa and Furnasare all larger than the one for Itaipu, but have a smaller installed generating capacity. The one with the largest hydroelecric production, Tucuruí, has an installed capacity of 8,000 MW, but it had to flood 2,430 square kilometres of land.