Itaipu Binational Hydroelectric Project

The Itaipu Binational Hydroelectric Project grew out of a 1973 treaty between Brazil and Paraguay establishing Itaipu Binacional, a jointly owned company charged with building and operating a dam on the shared stretch of the Parana River. Construction began in 1975 and the first generating unit entered service in 1984, with the full complement of 20 units completed by 1991 and later upgraded. The project stands as a rare example of a major energy scheme built and governed jointly by two sovereign states, with output split between them under the founding treaty, and it long supplied a large share of both countries' electricity.