28 June 2024
World Water Series – Exploring Leading Hydroelectric Plants Worldwide
Hydroelectricity, harnessed from the force of moving water, stands at the foremost renewable energy source for global electricity generation. Capitalising on both kinetic and potential energy as water propels turbines, subsequently powering generators. Thus, converting water’s energy into mechanical electricity.
Across the globe, numerous hydroelectric plants operate, but in this article, we will focus on select locations in China and Brazil to illustrate their magnitude, output, and local impacts.
Three Gorges Dam
Situated on the Yangtze River in China, the Three Gorges Dam stands as the world’s largest hydroelectric dam. Construction began in 2003, and by 2015 all dam turbines were running. In 2020, it produced a record-breaking 111.88 terawatts of electricity. The dam, towering 185 metres tall and stretching 2,335 metres long, comprises 28 million cubic metres of concrete and 436,000 metric tons of steel, making it the largest engineering project in China’s history.
While the dam contributes significantly to China’s renewable energy goals and prevents downstream flood, it has faced controversies. Archaeological sites have been lost, over a million residents displaced with inadequate compensation, and concerns about environmental impacts, including landslides and ecosystem alterations persist.
Itaipu Dam
Located on the Parana River between Brazil and Paraguay, the Itaipu Dam arose from a cooperative agreement between two nations. Construction began in 1971, with energy generation commencing in 1984. The power plant consists of a hollow concrete structure about 7.9km long with a maximum height of 196m. Running 20 turbine generators it can produce 14,000 megawatts of electricity, serving a vital and stable energy source for both countries without the reliance on fossil fuels.
However, the dam’s construction had led to loss of land and cultural significance, with communities on both sides displaced. Despite compensation being made and natural protection projects put in place it was not enough. Since 2003 social and environmental protection practises have been benefiting the area.
Xiluodu Dam
Situated on the Jinsha River in China, the Xiluodu Dam, inaugurated in September 2013 and fully operational in June 2014, ranks as the world’s third-largest hydroelectric plant. With 18 turbine generators, it generates 64TWh of power annually, significantly reducing carbon dioxide emissions and coal usage. Construction consists of a double curvature arch, concrete dam with a height of 278 metres and a width of 700 meters. Mainly developed for power generation, flood and sediment control while also improving the downstream navigation.
Despite its environmental benefits, the dam has displaced approximately 180,000 people and may have contributed to deadly landslides. Concerns about canyon deformations and dam safety have arisen, prompting proposed solutions such as Therm-Hydro Mechanical mechanism to address structural issues.
Belo Monte Dam
Located on the northern part of the Xingu River in Brazil. The Belo Monte Dam granted a license to be built in June 2011, completed in 2019, ranks as the world’s fourth-largest hydroelectric plant. Consisting of 3 dams, numerous dykes, and a series of canals. Operating with 18 turbines and having a capacity of 11,233 megawatts.
Controversies arose before the project, and even more issues have emerged since start of construction. Impacting indigenous communities and raising environmental concerns. Project developers miscalculated river flow rates, particularly problematic given the rivers seasonal nature. Turbines have had to be switched off when water levels are insufficient. Additionally, deforestation of the Amazon for agriculture is exacerbating climate change, leading to decreased rainfall, which poses structural risk to the unreinforced Pimental dam.
In conclusion, while hydroelectric power offers significant benefits, the construction and operation of hydroelectric plants entail complex social, environmental, and technical considerations. Balancing energy needs with environmental and social impacts remains a crucial challenge for the sustainable development of hydroelectricity worldwide.
