Where Is The World’S Largest Hydroelectric Dam?

Hydroelectric dams are an immense source of renewable power across the globe, capable of generating electricity for millions of people. The incredible scale and capacity of these structures is mind-boggling. When it comes to the world’s largest hydroelectric dams, there are several contenders vying for the top spot.

The current record-holder for the world’s largest hydroelectric dam is the Three Gorges Dam in China. This massive dam spans the Yangtze River in Hubei province. Since its full operation in 2012, it has taken the title of the world’s largest power station in terms of installed capacity. The Three Gorges Dam is a feat of modern engineering, but also highly controversial due to its staggering impact on the land, people, ecosystems and culture along the Yangtze River.

In this article, we will take a closer look at the specifications and history behind the construction of the Three Gorges Dam. We’ll also examine its purpose, impact and controversies. And we’ll see how it compares in scale to other mega hydroelectric dams around the world.

What is a Hydroelectric Dam?

A hydroelectric dam is a structure built across a river or stream to capture the kinetic energy from flowing water and convert it into electricity. Here’s a brief explanation of how hydroelectric dams work:

Dams are constructed to form large reservoirs that control the flow of water. The water in the reservoir has potential energy due to its height above the turbines. When the water is released from the reservoir, it flows through tunnels and spins the blades of turbines to activate generators. The generators then convert the mechanical energy of the spinning turbines into electrical energy. The electricity produced can be transmitted to homes, businesses, and industries through transmission lines.

Hydroelectric dams provide a renewable source of energy that does not directly produce greenhouse gas emissions. The technology is also flexible – electricity output can be adjusted to meet demand. Dams often serve additional purposes like flood control, irrigation, and recreation.

Largest Hydroelectric Dams

Hydroelectric dams harness the energy of flowing water to generate electricity. Here are some of the largest hydroelectric dams in the world based on key metrics like height, reservoir size, and power generating capacity:

• Three Gorges Dam, China – With a height of 185 meters and a reservoir that stretches 660 km, Three Gorges is the world’s largest hydroelectric dam by several measures.



• Itaipu Dam, Brazil/Paraguay Border – Itaipu is the world’s most powerful hydroelectric dam, with a generating capacity of 14,000 megawatts.
• Xiluodu Dam, China – At 286.5 meters tall, Xiluodu is the world’s tallest dam and third largest power station.
• Guri Dam, Venezuela – With a capacity of 10,200 megawatts, Guri is one of the largest dams in South America.
• Tucurui Dam, Brazil – The fourth largest hydroelectric power station in the world at 8,370 megawatts.
• Grand Coulee Dam, United States – One of the world’s largest concrete structures, able to produce 6,809 megawatts.

While there are larger dams by some measures, Three Gorges stands out as the world’s biggest and most powerful overall hydroelectric dam project.

Three Gorges Dam

The Three Gorges Dam is located in the town of Sandouping in the Yiling District of Yichang, in the Hubei province of central China. It spans the Yangtze River and is the world’s largest hydroelectric power station in terms of installed capacity (22,500 megawatts). The Three Gorges Dam is enormous, measuring 1.4 miles long and 607 feet high. It also created a reservoir over 400 miles long.

Construction on the Three Gorges Dam began in 1994 and was fully operational in 2012 after nearly 20 years of construction. The project was incredibly ambitious, requiring the relocation of over 1 million people living in the area that would become flooded by the reservoir. Significant funds were invested by the Chinese government to build new towns, factories, roads and other infrastructure to support the displaced people.

The purpose of the Three Gorges Dam is primarily for electricity production to replace fossil fuels, but it also plays a role in flood control, improved navigation and access along the Yangtze River. However, the project has been controversial due to the enormous environmental and social impacts from flooding hundreds of villages, displacing millions of residents, and altering the ecosystem of the Yangtze River.

Three Gorges Dam Specifications

The Three Gorges Dam is a massive hydroelectric gravity dam built on the Yangtze River in China. Here are some key facts and figures about its technical specifications:

Structure Height: 181 meters (594 feet)

Length: 2,335 meters (7,660 feet) – This makes it the longest concrete dam in the world

Reservoir Capacity: 39.3 cubic kilometers (9.4 cubic miles) – This creates the largest reservoir in the world by storage capacity

Number of Turbine Generators: 32 main turbines each with capacity of 700 MW, plus 2 smaller generators of 50 MW each

Total Electricity Generation Capacity: 22,500 MW (22.5 GW), making it the largest hydroelectric power station in the world by installed capacity

Flood Discharge Capacity: 102,500 cubic meters per second (3.6 million cubic feet per second), setting a world record for maximum flood discharge capacity for a hydroelectric dam

Construction Materials: 463,000 tons of steel and 28 million cubic meters of concrete were used to build the dam

The specifications of the Three Gorges Dam clearly demonstrate its unprecedented scale and capacity as the world’s largest hydroelectric dam.

Construction of the Three Gorges Dam

The Three Gorges Dam is one of the largest and most ambitious engineering projects ever undertaken. Construction began in 1994 and took nearly 20 years to complete, finally wrapping up in 2012.

The construction process involved several phases:

• 1994 – Construction on the dam formally kicked off.
• 1997 – The river was closed and damming began.
• 2003 – The main body of the dam was completed.
• 2006 – Reservoir water level reached 135 meters.
• 2008 – First generator operational.
• 2009 – Reservoir water level reached 156 meters.
• 2012 – All 32 main generators operational and project completed.

At its peak, nearly 30,000 workers were employed on the massive construction project. 44.3 million cubic meters of concrete were used to construct the dam, accounting for about 16% of global concrete output at the time. The Three Gorges Dam stands 185 meters tall and 2,335 meters wide.

Purpose and Impact

The Three Gorges Dam was built with several main purposes in mind. First, it aimed to generate clean hydroelectric power to help meet China’s growing energy demands. The dam has an installed capacity of 22,500 megawatts, making it the world’s largest hydroelectric power station. This provides electricity for millions of people in central and eastern China.

Second, the dam was built for flood control purposes. The dam is able to store huge amounts of water and release it slowly after a flood has passed, regulating the water flow during China’s rainy season. This protects communities along the Yangtze River from destructive flooding.

Third, the dam was intended to make the Yangtze River more navigable for large cargo ships to travel further inland. The reservoir’s depth allows 10,000-ton ships to travel upstream as far as Chongqing, over a thousand miles from the sea.

While the dam has achieved its main goals, it has also had major environmental and social consequences. The rising waters of the reservoir flooded towns, villages, and agricultural lands. Over 1.3 million people were displaced by the project. Additionally, the dam blocks fish migration and sediment flow down the Yangtze, harming local ecosystems and biodiversity.

Controversies

The Three Gorges Dam project has been highly controversial since it was first proposed in the early 1990s. Critics argue the project has caused severe environmental damage and required the relocation of over 1.2 million people. There are major concerns about the dam’s overall impact:

Environmental Impact: The enormous reservoir the dam created flooded hundreds of villages, towns, and cities along the banks of the Yangtze River. Entire ecosystems were altered by the flooding, threatening endangered plant and animal species. The dam has retained huge amounts of sediment, depriving downstream areas of nutrient-rich silt deposits. This is causing massive erosion and landslides. The project also increased the risk of earthquakes, landslides, and floods from additional pressure on the surrounding land.

Population Displacement: Over 1.2 million people were displaced by the dam’s reservoir. This lead to widespread criticism that the government was indifferent to local populations who were uprooted and displaced. Many argued the number of displaced people was underestimated by officials to justify the project. There were also concerns about lack of compensation and job training for displaced residents.

Cultural Destruction: As the reservoir waters rose, hundreds of cultural relics, archaeological sites, historic buildings, and entire cities with ancient architecture were flooded and lost forever. The government was criticized for not properly protecting cultural heritage sites before they were submerged.

Economic Viability: Questions remain about whether the economic benefits of the dam will outweigh its multi-billion dollar price tag. Corruption and embezzlement concerns have also surrounded the project’s massive budget. Critics argue the money could have been better spent on developing renewable energy sources.

Comparison to Other Dams

The Three Gorges Dam is the world’s largest hydroelectric dam by several measures. At 1.4 miles wide and 607 feet tall, it has greater dimensions than any other hydroelectric dam. The dam’s enormous reservoir capacity of 39.3 cubic kilometers also makes it the largest in the world. However, when it comes to power generation capacity, the Three Gorges Dam ranks third globally.

The Itaipu Dam on the Paraná River between Brazil and Paraguay is the hydroelectric dam with the highest electricity production capacity at 14,000 megawatts. The Three Gorges Dam has an installed capacity of 22,500 megawatts but typically operates at around 9,800 to 11,000 megawatts. The Guri Dam in Venezuela is the second largest power producing hydroelectric dam in the world with a capacity of 10,200 megawatts.

While smaller in electricity output, the Three Gorges Dam far exceeds other dams in size and scale. Its massive reservoir required the relocation of over 1 million people living in the potential flood zone. The project utilized 27 million cubic meters of concrete in its construction. While controversy surrounds its environmental and social impacts, the Three Gorges Dam remains the largest hydroelectric project ever undertaken.

Conclusion

In summary, the Three Gorges Dam on the Yangtze River in China is the world’s largest hydroelectric power dam. With a capacity of 22,500 MW, it is able to produce about one-tenth of China’s electricity needs. Construction of the dam took decades and required the relocation of over 1 million people living in the area that was flooded. While controversial, the Three Gorges Dam provides flood control, improved navigation, and renewable hydroelectric energy on a massive scale. Despite criticisms regarding environmental impact and displacement of residents, the sheer size and power generation capabilities make the Three Gorges Dam a modern engineered marvel and the undisputed largest hydroelectric dam in the world.