The wind blows up to eight times stronger at a height of 500 metres than at 120 metres – the hub height of modern turbines. Since it is impractical to build structures tall enough to take advantage of this surplus energy inventors are attempting to develop kites that can capture it. Ten start-up companies hoping to exploit the idea are holding an Airborne Wind Energy Conference at the University of Strathclyde, Glasgow, next week.
As every child discovers, keeping a kite airborne can be tricky and one large and heavy enough to produce electricity would be a hazard if it came down in the wrong place. The problem designers face is producing a kite that stays safely aloft and can harness wind energy in a form that produces electricity in a reliable manner.
One company thinks it has cracked the problem, developing a revolving kite that generates electricity as it climbs and will take off and land automatically on the same spot. They have already flown a three-metre wingspan prototype from a Swiss mountain producing electrical energy and landing safely. The next step is a commercial prototype 15 metres across which they think will suit islands and other remote locations where soaring energy kites won’t bother anyone.