In our previous story we told you how awesome the Iquaçu waterfalls really are. But there is more to do in this town. We also went to the Itaipu dam. This is the second largest dam in the world and we took the special tour which took us all the way into the dam. This is something quite extraordinary.
But more about the dam in a minute. Because we also met up with my nephew and his girlfriend Juliana. They are on holiday in Brazil and it was so much fun to meet again now thousands of kilometers from home. We had a great Brazilian dinner that first night. And on the bus to Foz we met Corinna from Germany. We had such a great time and we ended up spending all three days together.
But now back to the dam. Itaipu means ‘singing rock’ in the language of the natives that still live here in one of the many reserves. The dam is quite controversial because during the production of the dam al lot of nature was destroyed. We find it quite hard to now think of the energy to be ‘green’. And it also doesn’t’ help when the tour starts with an ultra propagandist movie about how much they do for nature. After the construction the company Itaipu Binacional started eight nature reserves to preserve the remaining Atlantic rainforests and compensate the already destroyed nature. Under big public protest by the way.
They started construction in 1975 by pushing the Paraná river. This took 3,5 years and the 33 million cubic meters of rock removed was partly used again in the construction of the dam. This took another 7 years and it resulted in a wall of 8 kilometers long and 200 meters high. The basis of the wall is 170 meters wide and on top its 12 meters.
The weight of the wall would be to heavy for the ground to hold and it meant they had to use a special construction for the wall. The construction consists of 140 columns in a triangular structure that can withstand the enormous pressure of all that water outside the wall. The wall itself is 10 meter of solid armed concrete. After the completion of the dam it was time to fill the lake behind it. It only took 2 weeks to fill all the valleys with water from the Paraná river. It is the eight largest river in the world.
In 1984 the first of 20 generators was put into use and the last in 2007. Together they now produce 14.000 megawatt a day. And the power is generated into two frequencies. 50 hertz for Paraguay and 60 hertz for Brazil. 120.000 liter of water run through the turbines with a constant of 92 rpm. We saw one of these rotors with our own eyes and the vibrations it makes can be felt throughout the building. It literally shakes all the time.
The Itaipu dam lies on Paraguayan and Brazilian territory and everything is divided in two. 10 generators generate power for Paraguay and 10 for Brazil. There are two CEO’s and the same number of people per nationality work inside the dam. A good example can be seen inside the control room. 3 Paraguayan and 3 Brazilians work here all the time. A contract between the two countries was made for 50 years and this is one of the many deals they made. Even the territory is equal and it is kind of a no mans land. The rules of the country are suppositions to the companies rules.
50% of the power goes to Paraguay but Paraguay only needs about 14%. The rest is sold to Brazil. This further means that the dam generates 80% of the power needed for Paraguay per year and 15% of the power needed for Brazil. Impressive numbers I would say.
The dam doesn’t aways produce power and then the excess water in the lake need to go somewhere. Therefor they installed a massive spillway that can spill water 40 times more than the Iquaçu falls. Sadly we were not able to see this with our own eyes. We had a small chance. Only 10% per year it is used.
The construction costed 12 billion dollar of which only 100 million came from the Paraguayan and Brazilian government. The biggest part came from European banks. The yields must be massive because somewhere in the mid nineties they sold off the last of their depths.
I do hope I used all the right phrases in this story. I am not an engineer so please forgive me. I particularly want to demonstrate how big of a dam it is and in what way it influences the area economically and ecological.