Stunt kite movements could be harnessed to generate power

Berlin-based wind energy developer NTS and experts from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart are now working on a project to harness the power of winds at altitudes of up to 500m.

Joachim Montnacher, an engineer at the IPA, said: ‘The kites fly at a height of 300–500m, perfectly positioned to be caught by strong winds. Cables, about 700m in length, tether the kites to vehicles and pull them around a circuit on rails.

‘A generator then converts the kinetic energy of the vehicles into electricity. The control and measuring technology is positioned on the vehicles.’ 

Compared with conventional wind farm technology that relies on rotors, this technology is said to offer a wide range of advantages: at a height of 100m wind speeds are around 15m/sec while at 500m they exceed 20m/sec.

‘The energy yield of a kite far exceeds that of a wind turbine, whose rotor tips turn at a maximum height of 200m. Doubling the wind speed results in eight times the energy,’ said Montnacher. ‘Depending on wind conditions, eight kites with a combined surface area of up to 300m² can equate to 20 conventional 1MW wind turbines.’