5 largest hydropower plants in the world
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If you’ve ever stood on the aisle of Hoover Dam, you will know that there is something awesome about huge hydropower plants. The largest dams in the world are listed among the largest man-made structures on the planet.
As the Hoover Dam nears its 100th anniversary, it is no longer in the top 10 in terms of installed capacity. In fact, it’s not even in the top 60. Over the past century, hydropower plants have grown a lot, with the lion’s share of megaprojects being built in China.
There are several ways to estimate the size of hydropower plants, for example according to the flooded area (the Churchill Falls Generating Station take the cake at 2700m2), the highest dam wall (the Jinping-I dam wall in China is 300 meters high, or slightly higher than the Eiffel Tower), or the annual output (the Three Gorges Dam in China, to which we will be back very soon).
For this article, let’s use the installed capacity in MW to list the five largest hydropower plants on the planet.
The Three Gorges Dam in China was built between 1994 and 2003 at a cost of nearly $ 32 billion. Straddling the longest river in Asia, the dam has an installed capacity of 22,500 MW and an average annual production of 103.1 TWh. The flooding of the region necessitated the displacement of 1.3 million (yes, a million) people as 13 towns and 1,600 villages were inundated. While these numbers are staggering, the main reason the Chinese government built a dam on the Yangtze was to prevent catastrophic floods that killed hundreds of thousands of people living along the river.
Fun fact: NASA calculated that the volume of water accumulated behind the dam wall has slow down the Earth’s rotation by 0.06 microseconds.
2. Itaipu Dam, ParanÃ¡ River, Paraguay and Brazil
With 14,000 MW, the world’s second largest hydropower plant has almost half the installed capacity of the Three Gorges Dam, but it generates almost the same average annual output (103 TWh) as the largest dam in China. Indeed, the ParanÃ¡ has a low seasonal variation while the flow of the Yangtze decreases considerably for six months out of 12. The Itaipu dam was built between 1971 and 1984 for an equivalent of 48.8 billion dollars in current dollars. The project is a binational enterprise between Paraguay and Brazil.
Fun fact: Itaipu Dam was chosen as one of the Seven wonders of the modern world by the American Society of Civil Engineers.
3. Xiluodu Dam, Jinsha River, China
Built in a spectacular landscape where mountains rise 6,600 feet on either side, the Xiluodu Dam is reminiscent of the giant wall of Game of thrones. It is part of a large network of hydroelectric projects along the Jinsha River, many of which are still under construction. Xiluodu has an installed capacity of 13,860 MW, an annual output of 55.2 TWh, and was completed in 2013 for $ 6.2 billion. Like the Three Gorges Dam, Xiluodu has a dual purpose of power generation and flood control.
Fun fact: The flow is controlled by five huge control doors, one of which is 1,600 tonne gate which is currently the heaviest in the world.
Belo Monte has an installed capacity of 11,233 MW and an annual production of 39.5 TWh. The largest dam in the Amazon basin is located on the Xingu, one of the tributaries of the Amazon, and is actually a complex of three dams, several dikes and canals that supply two power plants. Belo Monte was first proposed in 1975 and faced decades of opposition (including protests from indigenous Amazonian groups), trials and reshuffles before finally being built 40 years later in 2016.
Anecdote: hydropower plants provide more than 65% of electrical energy in Brazil.
5. Guri dam, Caroni River, Venuzuela
Otherwise known as the SimÃ²n Bolivar Hydroelectric Power Station, the Guri Dam opened in 1978 and was for a time the largest hydroelectric power station in the world. Guri has an installed capacity of 10,200 MW and an annual production of 53.41 TWh. The plant suffered three major production outages causing power outages to millions of homes in 2010 and 2016 (due to low water levels) and 2019 (attributed to sabotage).
Fun fact: Guri Dam has the 4th largest reservoir in the world.
The largest hydroelectric plants in the United States
The three largest hydroelectric plants by installed capacity in the United States are:
- Great Casting (8th worldwide with 6,809 MW)
- Bath County Pumped Storage Station (3,003 MW and described as the the biggest battery in the world)
- Robert Moses on Niagara Falls (3,840 MW of combined US / Canadian capacity).
Image Credit: gyn9037 / Shutterstock.com
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