The latest research suggests that high-altitude kites could be used to generate clean energy at a cost comparable with conventional power stations.
A chain of controllable ‘kites’ are attached to a looped cable stretching more than five miles into the sky to create a Laddermill. Strong winds acting on the ‘kitewings’ produce an upward force on one side of the loop and a downward force on the other, causing it to rotate. The slowly-turning cable drives a power generator in the base station.
Developers at Delft Technical University in the Netherlands hope to build a model within four years and claim that one Laddermill could generate 100MW of electricity, compared with only a few megawatts from a conventional wind turbine. They explain that winds at 30,000ft are 20 times more powerful than at sea level.