The environmental risks of hydroelectric power outweigh its benefits for the developing world, according to a new study published this week in the journal Proceedings of the National Academy of Sciences. The researchers say the prospect of cheap, renewable energy is distracting leaders from the damage that hydroelectric projects can inflict.
While this has become clear in Europe and the US, with dozens of dams removed each year, thousands of new projects are planned for Asia and Africa. Plans and construction on nearly 4,000 new dams are currently in progress in the developing world, according to BBC News.
Hydroelectric projects account for almost three quarters of renewable energy worldwide, but have been in decline in Europe and the US since the 60s. More projects have been removed than built since then, and hydropower now provides just 6 percent of US electricity.
Dams have displaced millions of people, disrupted river ecosystems, and even led to carbon emissions through the destruction of flooded forests and other land. Also, 90 percent of dams built since the 1930s turned out to be more expensive than planned.
“They make a rosy picture of the benefits, which are not fulfilled and the costs are ignored and passed on to society much later,” said the study’s lead author, Professor Emilio Moran, of Michigan State University.
For all of the harm that comes from these projects, the report points out that there is often minimal benefit for the people most affected. Two dams finished five years ago on Brazil’s Madeira river will produce far less power than expected due to climate change. The Grand Inga dam project in the Congo will increase Africa’s power generation by a third, but over 90 percent of the project’s electricity will go toward mining in South Africa, bypassing locals entirely.
“The nice goal of rural electrification has become completely subverted by large scale interests who are pushing this technology and governments are open to being convinced by them that this is the way to go,” Moran said.
The dams will not only damage biodiversity, but will also destroy food sources and livelihoods for local people. The report estimates that hydropower on the Mekong river in Southeast Asia will lead to $2 billion in lost livelihoods.
The researchers do not call for hydroelectric to be abandoned entirely, but for large projects to be scaled back, with more focus on other types of renewable energy.
“There should be more investment in solar, wind and biomass, and hydro when appropriate. As long as we hold them to rigorous standards where the costs and benefits are truly transparent.”