KiteGen

KiteGen is a concept developed in Italy for a wind harnessing machine that takes power from high altitude winds. The vertical axis orientation of the rotation is intended to eliminate the static and dynamic problems that prevent the increase in size of conventional wind turbines. The prototype STEM yo-yo is under construction at Berzano di San Pietro in Italy.

The KiteGen was originally conceived by Italian researcher Massimo Ippolito. While observing kite surfers he noticed the large amount of energy that the kite was able to collect and thought that a similar system could produce electricity. This idea seemed to Ippolito so risky that he put it aside for some years.

The problem of "capturing" the wind is solved by the use of Power Wing Profiles (Power kites) whose movements are controlled automatically by a computer. Through cables the kites are anchored to a structure that rotates, generating electricity. This structure is the turbine of the high altitude wind farm while the kites are the "blades" of the turbine.

The kites are flown on a predetermined trajectory, that can transform the exerted force on the cable, to an overall mechanical torque which rotates the vertical axis turbine. About twenty automatically controlled kites can keep rotating a turbine of 1,600 meters diameter at a speed of 15 revolutions per hour. This can generate 1 Gigawatt of power, equivalent to a medium size nuclear power station but with an estimated capital cost 10 times lower. In other words, 1 cubic Km of sky is able to provide 1 GigaWatt of power for 80% of the time in a year.

The kites extra added benefit lies in the fact that the length of cables allows them to reach heights over 500 meters, where the high altitude wind flows, without introducing structural weaknesses.

There are two wind flow bands that envelope the Earth globe. One passes over the southern hemisphere at the latitude of Patagonia, while the other passes over the northern hemisphere, over Europe. The flow height ranges from 800 meters up to 10,000 meters of altitude, while the width is 4,000 or 5,000 km. The average power of the wind is about 2 kW per square meter.

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Wikipedia