Brazil’s planned new 11-GW hydroelectricity station, to be located in the Amazon jungle, has attracted protests from celebrities from Sting, Sigourney Weaver, and James Cameron, who said it was a “real-life Avatar” situation. It looks like going ahead anyway now that Brazil has sold a contract to build the station, despite protesters arguing that the project will destroy the homes and livelihoods of thousands of people living beside the Xingu River, when 516 square kilometres of land is flooded for the project.
It’s a familiar story for hydropower and one that is increasingly heard with other sources of renewable energy. The impact on local residents (whether by destroying their homes or just their views) and on local flora and fauna is a big issue for many large wind and solar plants, not to mention CCS.
Hydropower certainly gets a worse rap. The scale and location of some new big hydro projects, such as the Three Gorges in China and the Ilusi dam in Turkey, have seen them linked with human rights abuses in a way that is rarely seen for other renewable projects.
Meanwhile, hydropower’s emissions credentials are somewhat tarnished by reports that projects where land clearing is not properly carried out prior to flooding can actually lead to more emissions than a comparable fossil fuel power plant. Still less endearing to environmentalists is the fact that big dams are sometimes sited in order to power mining projects.
But hydroelectricity has benefits that are sometimes overlooked. It accounts for 20 per cent of the world’s electricity, making it by far the biggest source of renewable energy. Its supporters point out that after a big initial outlay, hydro projects tend to have a good payback ratio, partly thanks to their longevity and low running costs. It’s also one of the few large-scale ways to store energy; and is touted as a good companion to wind and solar for this reason; excess energy can be used to pump more water into a hydropower dam, and used later. This is why Denmark exports excess wind energy to Norway.
It’s not limited to huge-scale projects either; ‘micro’ and ‘mini’ hydro projects (somewhere around the 10MW to 300MW range, depending on your definition) are growing faster than big projects — partly because much of the terrain suitable for hydropower has already been used, especially in Europe and America.
Also, supporters also point out, it’s good for both baseload and peak power supplies.
Except when there’s a drought. And this has been a problem recently for several countries, such as Vietnam. The NY Times reported this month that south-east Asian countries were blaming China’s hydropower, something that China has strenuously denied – and China itself has seen its hydropower output suffer from droughts. Meanwhile in the US, the Hoover dam is being upgraded to cope with lower water levels, which have tested its ability to keep generating large amounts of electricity.
It just goes to show — there are few easy options in energy.