TED: Electricity through Kites

This TED talk provides a brief overview of a kite based system to generate electricity. Some nice video in there of a kite flying around helping generate 10 kW. They are going for Mega-watt class machines with big kites flying at 2000 ft (~600 m). Video length: 6:35

Since the video is low on technical details, here is an article in the economist shedding further light on how such a system might work. [Link, subscription required]

Meanwhile, Wubbo Ockels of the Delft University of Technology in the Netherlands has been developing another approach to airborne wind generation at lower altitude, with backing from Royal Dutch Shell and Nederlandse Gasunie, a natural-gas company. Dr Ockels’s idea is that a kite (without rotor blades) be launched from a ground station, turning a generator as it rises to an altitude of several hundred metres. When it reaches its full height, it alters its shape to catch less wind, and can thus be reeled back in using much less power than it produced when it was being paid out.

An arrangement of two or more of these kites could act together to produce a steady supply of power. When one kite was being released, part of the electricity produced would reel the other kite back in, and vice versa. The whole system would thus remain in surplus, and if well designed could deliver a constant current. This system has the advantage that it requires only simple parts—generators, kites and cables—and should thus be much cheaper to build than a conventional turbine.