2. Itaipu Dam, Brazil and Paraguay (14 GW)
Located on the border between Brazil and Paraguay and built with the cooperation of both governments, the Itaipu Dam was hooked onto Paraguay's power grid in March 1984, with Brazil following 5 months later. The dam's power plant has 18 generators, it took 18 years to build and cost $18 billion. The massive facility provides three-fourths of Paraguay's electric power and about one-fourth of Brazil's. Building the dam required construction workers to divert the course of the Parana River around the current site of the dam with a 1.3-mile-long trench that measured 300 feet deep. To do this, workers removed some 50 million tons of dirt and rock.