This line is located inside one of the largest industrial complexes in the world, built astride one of the largest rivers in the world, in South America.
This is the Itaipu dam, built across the Paraná River, with a border that passes through the middle line of the river, between Paraguay and Brazil. This boundary therefore also passes through the middle of the dam!
Brazil has a common border with 10 countries (including 730 kilometers with Guyana, an overseas department of France).
Of the nearly 15,000 kilometers of land borders that Brazil has, it shares 1,290 with Paraguay.
By number of kilometers, only Russia and China have longer international land borders.
For its part, Paraguay has common borders with only three countries, for a total of 3,920 kilometers, landlocked between Bolivia, Argentina, and therefore Brazil.
The imposing ITAIPU dam was built about fifteen kilometers upstream from the triple border between Argentina, Brazil and Paraguay. This tripoint is located at the confluence between the Rio Paraná and the Rio Iguaçu.
I take this opportunity to announce that the Iguaçu Falls, among the most spectacular in the world, will soon be the subject of a video report.
The Paraná River, more than four thousand kilometers long, is a little-known river, but one that ranks among the most important in international rankings. It is thus generally ranked 10th in the world in terms of flow and is 5th in terms of catchment area (behind big names such as the Amazon, the Congo, the Nile, or the Ob).
Paraná is equipped with many hydroelectric works. As it separates Brazil and Paraguay over almost 200 kilometers, it is not surprising that these two countries, both then ruled by military dictatorships, and despite their conflicting relations, came to an agreement, in the years 1960, to exploit this common resource. In 1973, the two countries agreed on a 50:50 sharing of the energy produced. In the same Treaty, Paraguay undertakes to resell exclusively to Brazil all the energy produced that it has not consumed, at a fixed price, until the end of this agreement in 2023.
The entire length of the reservoir, on the Paraná, is common to Brazil and Paraguay, over more than 150 kilometers, justifying the principle of production sharing.
The reservoir covers an area of 1,350 km², or just over half the size of Luxembourg. Economic interest prevailed over environmental interest for the choice of this site, with nearly 1,500 km² of agricultural land and flooded forests, and displaced populations. In addition, shortly after the beginning of the current location of the lake of the dam, there was a set of seven groups of spectacular waterfalls, over a width of almost 5 kilometers, with a flow rate far greater than that recorded at the extraordinary Iguazu Falls. This natural site was definitively submerged at the end of 1982, in the space of two weeks, with the filling of the dam.
The construction of the work began in 1975, and ended in 1982. But the plant was far from being operational. All that remained was to install the 18 turbo-alternators originally planned.
A turbo-alternator is the coupling of a turbine and an alternator in order to transform the mechanical power of a moving fluid (here river water) into electricity.
The first electricity production unit entered service in 1984, and the eighteenth in April 1991, each with a capacity of 700 MW. Two new groups were commissioned in 2005 and 2006, bringing the total installed power to 14,000 MW. This currently makes it the third largest hydroelectric power station in the world in terms of installed power, behind two dams built in China, including the Three Gorges dam.
The Three Gorges hydroelectric power station in China, commissioned in 2012, is the most powerful in the world with 22.5 Gigawatts installed, thanks to its 32 700 Megawatt turbines.
The Itaipu engine room, which houses the 20 turbo-generators, is located at the foot of the dam, in a huge concrete cavern. It is almost a kilometer long, 100 meters wide and 100 meters high. The penstocks, each 142 meters long, 10.50 meters in diameter, and weighing 1,450 tons each, end in this room.
It is in this room that the 20 turbines are installed, each coupled to an alternator, under a drop height of 118 meters. The dimensions of each turbine-alternator group are impressive. Thus, the turbine weighs 300 tons for a diameter of 8 meters 60. The alternator is even more excessive, with a weight of 1,760 tons for a footprint of 16 meters in diameter.
In operation, the alternator rotates at a constant speed at just over 90 revolutions per minute. Very impressive.
In addition, a treaty was also signed between the two countries operating the Itaipu plant and Argentina to govern the water levels downstream of the dam and the volumes of water discharged from the plant, in order to guarantee Argentina a level of water adequate to the needs of the cities of Rosario and Buenos Aires.
