Figures from a new database on sustainable energy production indicate that global hydropower output is set to double on the back of a boom in dam building throughout the developing world.

The study, led by Dr. Christiane Zarfl at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin, found that rising demand for clean energy from renewable sources has prompted a surge in hydropower development following a protracted plateauing of growth.

The world is currently host to an unprecedented number of hydropower dam projects, primarily in the developing economies of Asia, Latin America and Africa.

Renewables currently account for roughly 20 per cent of global electricity production. While solar and wind power dominate media coverage when it comes to clean energy, hydropower continues to comprise the vast preponderance of renewable energy, contributing 80 per cent of the global total.

“Hydropower is an integrated part of transitioning to renewable energy and currently the largest contributor of renewable electricity,” said Zarfl.

According to the database, around 3,700 planned dam projects are expected to double total hydropower capacity to 1,700 gigawatts over the next two decades.

While China will retain the title of the world’s biggest builder of hydropower projects, particularly given a spate of dam construction in the Yangtze basin, the country’s share of global hydropower generation will fall from 31 per cent at present to 25 per cent as other regions ratchet up capacity.

The Amazon and La Plata basins of Brazil will be host to the largest total number of new dams in South America, and the Ganges-Brahmaputra basin in India and Nepal will rival the Yangtze basin in terms of Asian dam building.

Zarfl warns, however, that while this surge in hydropower deployment may bring clean, low-carbon energy to developing economies, it could also have severe ecological ramifications given the impact of large-scale dam construction on local environments. Concerns over these impacts were the motivation behind the compilation of the hydropower database.

“It is vital that hydropower dams do not create a new problem for the biodiversity the biodiversity in the world’s freshwater systems, due to fragmentation and the expected changes in the flow and sediment regime,” said Zarfl. “That is why we have compiled available data on future expected hydropower dams – to form a key for evaluating where and how to build the dams and how to operate them sustainably.”