Planned dams to double hydropower output

An unprecedented boom in hydropower dam construction is underway, with 3,700 major dams expected to be built in the next twenty years, doubling hydropower electric capacity to 1,700 GW.

By comparison, global wind capacity totalled 318 GW by the end of 2013.



The figures come from a University of Copenhagen study which found that renewables account for 20% of the global electricity production today, with hydropower contributing 80% of the total share.



If all planned dams are built, hydropower powerhouse China will remain the global capacity leader although its share of total hydropower production will decline from 31% to 25%, due to increases in other parts of the world.



The Amazon and La Plata basins in Brazil will have the largest total number of new dams in South America, while the Ganges-Brahmaputra basin (mainly India and Nepal) and the Yangtze basin in China will face the highest dam construction in Asia.



Environmental impact



However, the construction boom occurs primarily in countries that also hold some of the world's most important sites for freshwater biodiversity.



"Hydropower is an integrated part of transitioning to renewable energy and currently the largest contributor of renewable electricity," said Dr. Christiane Zarfl, who contributed to the research.



"But it is vital that hydropower dams do not create a new problem for the biodiversity in the world's freshwater systems, due to fragmentation and the expected changes in the flow and sediment regime. That is why we have compiled available data on future expected hydropower dams - to form a key foundation for evaluating where and how to build the dams and how to operate them sustainably."



Earlier this week, Greenpeace International predicted that wind capacity would reach 2000GW by 2030- enough to supply 20% of the world's energy.

The future of hydropower

Brad Allen