European researchers say an unprecedented surge in the construction of hydropower dams around the world could double renewable electricity generation, but potentially at the expense of freshwater wildlife.
Scientists at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin have developed a new database, called Biofresh Project, to help planners design the most sustainable modes of hydropower possible.
The problem may be thornier than many people believe, according to Christiane Zarfl, who worked on the IGB project. She said global demand for clean electricity has sparked a welcome new era of hydropower, which is emission-free and inexpensive.
Until recently there’s been a flattening trend globally in building hydroelectric dams, but now governments and utilities are building or planning about 3,700 major dams, most in the developing and emerging economies of Africa, South America and Southeast Asia.
Zarlf, of Tubingen University, cautions that the surge of development has a serious downside: The projects could reduce the number of the world’s free-flowing rivers by about 20 percent, threatening freshwater biodiversity, especially in these regions, which include some of the world’s key areas of freshwater biodiversity.
The study found, for example, that the greatest number of dams are planned for in India’s Ganges-Brahmaputra basin, and the Yangtze basin in China, both of which have among the highest rates of biodiversity in the world.
According to Zarlf, “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.”
The IGB’s findings were presented on Oct. 24 at the international congress Global Challenges: Achieving Sustainability, hosted by the University of Copenhagen. They also were published in the journal Aquatic Sciences.
Zarlf said the purpose of the IGB study was not to oppose new hydroelectric dams, but to help evaluate where to build them and how so that they can be operated sustainably.
Klement Tockner, the director of the IGB project, agreed. “When building new dams, it is important to follow a systematic management approach that considers the ecological, social, and economic consequences of multiple dams within a river basin,” he said.
About 20 percent of electricity produced today is generated by renewable methods. Of this amount, fully 80 percent comes from hydropower. The study concludes that new dams are expected to more than double the total electrical capacity of hydropower to 1,700 gigawatts within 20 years.
By Andy Tully of Oil price.com
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Andy Tully is a veteran news reporter who is now the news editor for Oilprice.com