Itaipu Dam produces the most energy of any hydroelectric dam in the world

Tijana Radeska
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The hydroelectric dam Itaipu is on the Paraná River, which is the natural border between Paraguay and Brazil and the seventh biggest river in the world. Although Argentina first contested the dam, the negotiations and resolution of the dispute ended up creating a plan for the Argentine-Brazilian border to be implemented. Negotiations about the Itaipu Power Plant started between Paraguay and Brazil in the 1960s.

On July 22, 1966, the act “Ata do Iguaçu” was agreed to between the two countries and signed by their ministers of foreign affairs: Raúl Sapena Pastor, the Paraguayan minister, and the Brazilian, Juracy Magalhães. In 1973, the treaty giving the go-ahead to the power plant was signed. “Itaipu” was the name of an island that existed near the site before the construction. It means “the stone that dreams and sings” or “the sounding stone” in the Guarani language.

The route of the Paraná River was shifted on October 14, 1978, so that the riverbed could dry to allow the construction of the dam. Along with it, 50 tons of rocks and earth were replaced. After a year, the Acordo Tripartite was signed between Argentina, Brazil, and Paraguay, which was an agreement that determined the levels of the river and how much they could be changed as there were several hydro electrical undertakings on the river at the time.

Itaipú Power Plant. Author: Angelo Leithold. CC BY-SA 3.0.

On October 13, 1982, the formation of the reservoir began. By that time, the work on the dam was completed, and the side canal’s gates were closed. During this period, there were heavy rains and floods that saw the water to rise 330 feet, reaching the spillway gates on the 27th of October.

Itaipu Dam, Paraguay/Brazil. Author: International Hydropower Association (IHA). CC BY 2.0.

The first generation unit in Itaipu started running on May 5, 1984. Each year, until 1991, there were two or three units installed. There was a clause in the treaty signed by the three countries that the number of generation units operating simultaneously could not exceed 18. However, in September 2006 and then in March 2007 the last two of the total 20 electric generation units started operating. This completed the power plant, and the installed capacity rose to 14 GW.

Some of the 20 tubes leading water to the turbines at Itaipú Dam. Author: Wutzofant. CC BY-SA 3.0.

Ten of the 20 generator units generate at 60 Hz for Brazil and 10 generate at 50 Hz for Paraguay. The production of the Paraguayan generators far exceeds the load in Paraguay, so most of it is directly exported to Brazil, from where two 500 miles long, 600 kV HVDC lines provide energy for the cities of Rio de Janeiro and São Paulo, and the areas around them. The terminal equipment there converts the power to 60 Hz.

Operating ring in Itaipu Dam. Author: Marco Verch. CC BY 2.0

On the site of the dam there used to exist the Guaíra Falls, the largest waterfall by volume in the world, but the whole National Park was liquidated by the Brazilian government, and the falls were drowned. Before the destruction of the falls, tourists from all over the world gathered to see them for the last time. At one point the bridge that overlooked the falls collapsed because it was overcrowded, and 80 people died.

The dam undergoes expansion work.

There were around 10,000 families that lived near Paraná River who were displaced when the construction of the dam began. There were 40,000 Brazilian and Paraguayan workers involved in building the dam. The amount of concrete used for the Itaipu Power Plant is equal to building 210 Estádio do Maracanã football stadiums, while the iron would be enough for the construction of 380 Eiffel Towers. The volume of rock and earth excavated in Itaipu is 8.5 times greater than in the Channel Tunnel, while the volume of concrete used is 15 times greater. The Itaipu dam is one of the most expensive things ever built in the world.

Central Control Room (CCR) at Itaipu Power Plant. Author: Anagoria. CC BY 3.0.

The complete length of the dam is 23,737 feet. The spillway is 1,585 feet long. There are 14 segmented spillways at Itaipu with a maximum flow of 62.2 thousand cubic meters per second which is equivalent to 40 times the flow of the Iguaçu Falls, the biggest waterfall system in the world. The crest elevation is 738 feet. The dam is 643 feet high which is equivalent to a 65-story building. The electricity produced by the Itaipu Dam is 55 percent cheaper than the other types of power plants in the area.

Panoramic view of the Itaipu Dam. Author: Martin St-Amant. CC BY-SA 3.0.

In 2016, the Itaipu Dam’s hydroelectric power plant set a new world record by producing the most energy of any other plant in the world: 103,098,366 megawatt hour (MWh). In 2015 and 2016, the Itaipu plant surpassed the Three Gorges Dam plant in energy production. On November 10, 2009, the plant’s transmission was completely disrupted, possibly because of a storm that damaged three high-voltage transmission lines. There weren’t any other, serious damages to the dam but the whole country of Paraguay was blacked out for 15 minutes, while Rio de Janeiro and São Paulo fell into darkness for more than 2 hours. Reportedly, there were 50 million people affected.

Read another story from us: At least 96 workers lost their lives during the construction of Hoover Dam

The Itaipu dam is incredible, and it was elected as one of the seven modern Wonders of the World in 1994 by the American Society of Civil Engineers. The American composer Philip Glass composed a symphonic cantata, “Itaipu,” honoring the construction.