A new generation of free-standing turbines will liberate hydroelectricity from its dependence on dams
IN TODAY’S green world, hydroelectric dams are often unwelcome. Though their power is renewable and, on the face of it, carbon-free, there are lots of bad things about them, too. Blocking a river with a dam also blocks the movement of fish upstream to spawn and the movement of silt downstream to fertilise fields. The vegetation overwhelmed by the rising waters decays to form methane—a far worse greenhouse gas than carbon dioxide. The capital cost is huge. And, not least, people are often displaced to make way for the new lake. The question, therefore, is whether there is a way to get the advantages without suffering the disadvantages. And the answer is that there may be....MORE
