Itaipu Hydroelectric Dam is the world’s second-largest operational hydroelectric power plant in terms of installed power. With an installed generation capacity of 14GW, the plant is operated by Itaipu Binacional and located on the border between Brazil and Paraguay. Energy generated by Itaipu helps to meet the demands of the two countries. Approximately 90% of the energy generated by the plant is used by Brazil.
The Itaipu dam and the hydroelectric plant are on the Paraná River. The construction of the dam began in February 1971 and cost $19.6bn. The first unit began generating power in May 1984 and the second generating unit started operating the same year. Itaipu has 20 generating units, each with a capacity of 700MW.
The dam’s reservoir, which covers an area of 1,350km², is the seventh-largest reservoir in Brazil with the best coefficient of water utilisation of 10.4MW/km². Itaipu generated 79.44 million MWh of energy in 2019, while plant achieved a milestone in 2016 by setting a new world record for annual power generation with a production of 103.1 million MWh.
It is equal to the energy consumed by Paraguay for 11 years and by Argentina for one year.
The energy generated in 2008 was used to supply 87% of the electricity consumed in Paraguay and 19% demanded by the Brazilian interconnected system.
A consortium, comprising GE Power and CIE Sociedad Anonima, was awarded a contract to supply electrical equipment for the replacement of obsolete equipment. The three-year contract supports the modernisation project of the Itaipu Dam. The new equipment will be integrated into the 24 overhead cranes and gantries to improve their efficiency.
The proposal for construction of Itaipu was made in February 1971. Paraguay and Brazil signed a treaty in April 1973 for the exploitation of the Paraná River by both countries for hydroelectric power. The treaty put the maximum number of generating units at 18. The plant has two other units as a reserve.
Itaipu Binacional was created in May 1974 to undertake Itaipu’s construction. The construction of the plant began in January 1975.
The first two units of the plant were installed in 1984, while the 19th unit was installed in 2006. The plant was completed with the installation of its 20th unit in 2007.
An environmental study was taken up by the Meteorological System of Paraná (Simepar) from September 1997 to 2000. It was found that the reservoir had not influenced the climate of the region.
The treaty, when originally signed, required Paraguay to sell its unused electricity to Brazil for $124m a year until 2023. The treaty expired that year and caused widespread discontent in Paraguay for a number of years.
In July 2009, the two countries signed a deal, under which Brazil agreed to triple its payments to Paraguay. It also permitted Paraguay to sell excess power directly to Brazilian companies instead of going through the Brazilian electricity monopoly. The deal also included the construction of an electricity line, which was completed by 2012.
Itaipu Hydroelectric Dam construction
A consortium of US-based IECO and Italy-based ELC Electroconsult carried out the viability studies of the project and its construction.
The Itaipu project included the construction of a 7,919m-long and 196m-high dam. The dam was built to form an artificial lake that accumulates water. Itaipu’s main dam was made from concrete while the auxiliary dams were made from rockfill and earth fill rocks and earth from local excavations.
The construction of the dam involved installing four rock-crushing centres, two on each bank, with a total capacity of 2,430t/h, and six concrete mixing plants with a capacity of 180m³/h each. The site also included two monorails, seven aerial cableways and 13 tower cranes. The Itaipu dam used 12.3 million m³ of concrete.
Itaipu Hydroelectric plant details
The power plant includes a turbine, generator, excitation system and speed governor. All units are separated by a distance of 34m. The power plant has three substations, of which two are gas-insulated and one is a conventional 50Hz substation.
The installed generation capacity of the plant is 14GW, while the instantaneous generation and accumulated generation capacities are 10.571MW and 85 million MWh. The accumulated generation of the plant is 1.6 billion MWh.
The plant utilises a hydrometeorological telemetry system (HTS) to obtain data for forecast, supervision and operations control. This model reads information from sensors and relays them to the plant through satellite and the internet.
Power transmission from Itaipu
Furnas Centrais Elétricas of Brazil and Administración Nacional de Electricidad (ANDE) of Paraguay are responsible for the transmission of power to load centres.
The power generated by Itaipu is distributed through an interconnected system. The system is connected from Brazilian substation Foz do Iguaçu owned by Furnas to the Paraguayan right bank substation within the plant’s area.
The two gas-insulated substations of the power plant are of 50Hz and 60Hz. The 50Hz substation contains six 500kV transmission lines. Two lines are 2km long and link the power plant to the right bank. Two 10km-long lines connect the power plant to the Foz do Iguaçu substation. The remaining two transmission lines connect the right bank and Foz do Iguaçu substations.
The 60Hz substation contains three to four 500kV transmission lines. Each line links the power plant to the Foz do Iguaçu substation.