The World′s Largest Hydroelectric Power Plants

As we move further into the 21st century, the world’s insatiable demand for energy continues to climb, resulting in an escalating search for new power sources. At the heart of this quest are the contenders for the largest hydro power plant in the world.

The world is home to a huge array of hydroelectric power stations. From the smallest, providing energy for local villages, to the largest, powering nations. Power from water has been used for thousands of years and today, it provides roughly 18% of the world’s electricity.

Majestic in their size and awe-inspiring in their capacity to harness nature’s astonishing power, these colossal structures underscore humankind’s ability to generate energy by utilising the power of the natural world.

There are a number of metrics that can be used to determine the biggest hydro power plant in the world including reservoir volume of the dam, physical size of the powerplant, annual energy production measured in gigawatt-hours, or installed capacity, referring to the maximum amount of electricity that a power plant can potentially produce if conditions are ideal.

For this article, we’re going to use installed capacity in megawatts.

Location: Khakassia, Russia | Installed Capacity: 6,400 MW

Russia’s largest power plant is a contender for the world’s largest hydro-electric dam. Known as the Sayano-Shushenskaya Dam, it was built between 1963 and 1975 on the Yenisei River in southern Siberia. It was named after a Soviet-era Minister of Energy and Electrification, Pyotr Neporozhny. Over 70% of the generated energy is used to supply the Siberian-based smelters for Rusal, the world’s second largest aluminium company.

Location: Washington, USA | Installed Capacity: 6,809 MW

The Grand Coulee Dam on the mighty Columbia River opened in 1942. While it isn’t the largest hydroelectric power plant in the world, it’s one of the most famous. The dammed river created the Franklin Delano Roosevelt Lake, and in addition to power generation it provides water for irrigation projects spanning over 2,700 square kilometres.

Location: Bolívar State, Venezuela | Installed Capacity: 10,235 MW

Also known as the Guri Dam, one of the world’s largest hydro power plants is reported to supply almost 70% of Venezuela’s energy, saving the country the equivalent of almost 48 million litres of oil every day. Sitting on the Caroni River, the reservoir created by the dam is one of the biggest in the world, with a capacity of 135 billion cubic metres of water and a surface area of over 4,200 square kilometres.

Location: Paraná River, Brazil/Paraguay | Installed Capacity: 14,000 MW

Straddling the border of Paraguay and Brazil, the Itaipu Dam was the world’s largest hydroelectric dam for almost twenty years until the Three Gorges Dam was built. It was constructed between 1971 and 1984 at a 2022-equivalent cost of $55 billion. It’s believed to supply Paraguay with almost 90% of its electricity, and around 15% of Brazil’s. In fact, while Paraguay is entitled to 50% of the electricity produced by the dam, it only consumes a fraction of that amount and sells the majority of its share back to Brazil.

Location: JInsha River, China | Installed Capacity: 16,000 MW

The second-biggest hydro power plant in the world went fully operational in December 2022 and cost over $30 billion. The plant is estimated to generate over 62 billion kilowatt-hours of electricity annually, reducing carbon emissions by a reported 248 million tonnes. The dam impounded the Jinsha River, and the newly-formed reservoir has an astonishing capacity of almost 18 billion cubic metres of water.

Location: Hubei Province, China | Installed Capacity: 22,500 MW

One of the world’s most ambitious and complex engineering projects, the $32 billion Three Gorges Dam was completed in 2003. Not only is it the largest hydroelectric power plant in the world, it’s the largest power station of any kind on the planet. At 2,335 metres wide, it’s the world’s biggest dam.

As the world’s largest hydro power plant, the Three Gorges Dam is also believed to be the world’s single largest source of electricity – providing around 2% of China’s entire energy demand.

When constructed, 40 trillion kilograms of water from the Yangtze River built up behind it to a height of 175 metres above sea level. Indeed the build-up of water – effectively the redistribution of mass – was so remarkably powerful it’s said to have caused the Earth’s moment of inertia to alter slightly, slowing the rotation of the Earth by six-hundredths of a millionth of a second, or 0.06 microseconds.

The harnessing of water to power the world has seen mankind undertake truly awe-inspiring engineering feats. These hydroelectric power plants underscore the convergence of human ambition and the indomitable force of nature, resulting in breathtaking structures that not only power cities but also shape the planet.

From the chilling Siberian landscapes where the OJSC PS Neporozhny Sayano-Shushenskaya Hydro Power Plant operates, to the tropical terrain of Venezuela’s Guri Dam, and all the way to the colossal Three Gorges Dam in China, these engineering marvels continue to captivate us with their sheer scale and capacity.

The record-breaking Three Gorges Dam stands as a testament to the immense potential of hydroelectric power, offering an intriguing glimpse into what the future could hold as the thirst for energy sources grows. The impact of such monumental works of engineering is felt far beyond their immediate environments, influencing not just the local ecosystems and economies, but also the very planet itself.