Itaipu Dam: The largest operating hydroelectric facility

The Itaipu Hydroelectric Power Plant is located on the Paraná River between Brazil and Paraguay. The Paraná River is the seventh largest river in the world and the second largest in South America. Itaipu Dam is the world’s largest hydroelectric power facility and it is a joint effort of the governments of Brazil and Paraguay.

The project ranges from Foz do Iguaçu, in Brazil, and Ciudad Del Este in Paraguay, in the south to Guaíra and Salto Del Guaíra in the north. The name Itaipu was taken from an isle that existed near the construction site. In the Guarani language, “Itaipu” means "the sound of a stone".

The Itaipu Reservoir is 170 km long with an area of 1.35 km2 and has a volume at maximum normal level of 29 billion tons of water. It consists of a series of various types of dams the height of the dam reaches 196 m, its length 7.76 km. The Powerhouse is located at the toe of the main Dam, most of it on the river bed and the rest on the Diversion Channel.

The main structure, a hollow, concrete gravity dam, has a powerhouse capable of generating 14,000 megawatts (MW) of electricity. The main powerhouse has 18 Francis turbines each with a rated power of 715 MW. The Spillway is located on the right bank, and it has 14 segmented sluice gates with a total discharge rate of 62,200 cubic meters per second.

The volumes of construction in Itaipu are also impressive. The volume of iron and steel utilized in the Dam structure would be enough to build 380 Eiffel Towers, and the volume of concrete used in Itaipu represents 15 times the volume utilized to build the Channel Tunnel between France and England.

The power plant is a major tourist attraction in the Foz do Iguacu area. More than nine million visitors from 162 countries have visited the structure since it was completed in 1991.

HISTORY

On June 22, 1966, the Ministers of Foreign Affairs of Brazil, Juracy Magalhaes, and of Paraguay, Sapena Pastor, signed the "Act of Iguaçu ". A study was carried out under this Act that assessed the potential hydraulic resources of the Paraná River, which is jointly occupied by the two countries. In 1967, the Brazilian-Paraguayan Joint Technical Commission was established to carry out the study and the development of the Paraná River.

On April 26, 1973, the two governments of the states signed a treaty "for the development of the hydroelectric resources of the Paraná River". They founded ITAIPU Binacional (cooperation with the legal, administrative and financial capacities and technical responsibility to plan set up and operate the plant) in May 17, 1974.

The construction work started in 1975, reaching its peak in 1978 with 30 000 people at work. Monthly on-site concrete production reached 338 000 m³. In total, 15 times the mass of concrete used for the "Euro Tunnel" was supplied.

It took almost three years for workers to carve a 1.3-mile long, 300-foot deep, 490-foot wide diversion channel for the river. Fifty million tons of earth and rock were removed in the process. Engineers chose a hollow gravity dam because it required 35 per cent less concrete than a solid gravity dam. The open dam is still heavy and sturdy enough to resist the thrust of water entirely by its own weight.

Sometimes the dam can get blocked with mud and silt. It is expensive to clean the dam out. The mud and silt can cause diseases in the water in the reservoir. Unless the water in the reservoir is cleaned, people can get these diseases. The land behind the dam and reservoir had to be flooded. Much of this land was rainforest, and the trees had to be cut down. Many parrots died because their homes in the trees were destroyed.

In 1982 the land behind the dam was flooded, and within 14 days, the reservoir was created. Unit 1 started to operate in December 1983. Electrical grid connection to Paraguay was established in March 1984, Brazil was connected 5 months later. In March 1991 the last Unit (No.18) was put into operation.

The magnitude of the project also can be demonstrated by the fact that in 1995 Itaipu alone provided 25% of the energy supply in Brazil and 78% in Paraguay.

The Itaipu Dam is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The name "Itaipu" was taken from an isle that existed near the construction site. In the Guaraní language, Itaipu means "the sound of a stone".

The dam is the largest operating hydroelectric facility in terms of annual energy generation, generating 94.7 TWh in 2008 and 91.6 TWh in 2009, while the annual energy generation of the Three Gorges Dam was 80.8 TWh in 2008 and 79.4 TWh in 2009.The dam's 14,000 MW installed capacity is second to the Three Gorges Dam's 22,500 MW, though. It is a binational undertaking run by Brazil and Paraguay at the Paraná River on the border section between the two countries, 15 km (9.3 mi) north of the Friendship Bridge. The project ranges from Foz do Iguaçu, in Brazil, and Ciudad del Este in Paraguay, in the south to Guaíra and Salto del Guairá in the north. The installed generation capacity of the plant is 14 GW, with 20 generating units providing 700 MW each with a hydraulic design head of 118 m. In 2008 the plant generated a record 94.68 TWh, supplying 90% of the electricity consumed by Paraguay and 19% of that consumed by Brazil.

Of the twenty generator units currently installed, ten generate at 50 Hz for Paraguay and ten generate at 60 Hz for Brazil. Two 600 kV HVDC lines, each approximately 800 km long, carry both Brazilian and Paraguayan energy to São Paulo where the terminal equipment converts the power to 60 Hz.

Negotiations between Brazil and Paraguay

The concept behind Itaipu Power Plant was the result of heavy negotiations between the two countries during the 1960s. The "Ata do Iguaçu" (Iguaçu Act) was signed on July 22, 1966, by the Brazilian and Paraguayan Ministers of Foreign Affairs, Juracy Magalhães and Sapena Pastor, respectively. This was a joint declaration of the mutual interest in studying the exploitation of the hydric resources that the two countries shared in the section of the Paraná River starting from, and including, the Salto de Sete Quedas, to theIguaçu River's watershed. The Treaty that gave origin to the power plant was signed in 1973.

The terms of the treaty, which expires in 2023, have been the subject of widespread discontent in Paraguay. The government of President Lugo vowed to renegotiate the terms of the treaty with Brazil, which long remained hostile to any renegotiation.

In 2009, Brazil agreed to a fairer electricity payment to Paraguay and allowed Paraguay to sell excess power directly to Brazilian companies instead of solely through the Brazilian electricity monopoly.

In 1970, the consortium formed by the companies IECO (from the United States of America) and ELC Electroconsult S.p.A. (from Italy) won the international competition for the realization of the viability studies and for the elaboration of the construction project. Work began in February 1971. On April 26, 1973, Brazil and Paraguay signed the Itaipu Treaty, the legal instrument for the hydroelectric exploitation of the Paraná River by the two countries. On May 17, 1974, the Itaipu Binacional entity was created to administer the plant's construction. The works began in January of the following year. Brazil's (and Latin America's) first electric car was introduced in late 1974; it received the name "Itaipu" in honour of the project.

Social and environmental impacts


When construction of the dam began, approximately 10,000 families living beside the Paraná River were displaced.


The world's largest waterfall by volume, the Guaíra Falls were drowned by the newly formed Itaipu reservoir. The Brazilian government liquidated the Guaíra Falls National Park, and dynamited the submerged rock face where the falls had been, facilitating safer navigation, but eliminating the possibility of restoring the falls in the future. A few months before the reservoir was filled, 80 people died when an overcrowded bridge overlooking the falls collapsed, as tourists sought a last glimpse of the falls.


The American composer Philip Glass has also written a symphonic cantata named Itaipu, in honour of the structure.