RWE Renewables GmbH (RWE Renewables) and SkySails Power GmbH (SkySails Power) are planning to fly a 120 m2 kite to a height of up to 400 m above ground to utilise high-altitude winds for generating electricity. The two companies have now entered a collaboration agreement on this pilot project. RWE Renewables is purchasing an innovative airborne wind energy system with an output of up to 200 KW from SkySails Power, and will operate the system and evaluate the technology during the three-year pilot project. Currently, suitable locations in Germany are being assessed.
Airborne wind energy systems harness the strong and steady winds at heights of several hundred metres above ground. Part of the SkySails Power system is a ground station consisting of a winch with an integrated generator. During its ascent in a controlled trajectory, the kite pulls rope from the winch, and the built-in generator produces electricity from the rotational energy.
Once the tether is completely unspooled, the kite is winched back in. It brings itself automatically into a position of very low resistance so that it can be hauled back easily. The generator now acts as a motor operating the winch. This process only requires a fraction of the energy that has been generated during the active phase. The cycle can then start over again.
Current airborne wind systems have a maximum capacity of 100 - 200 KW. Developing this technology further will increase the potential output from KW to MW and thus make it attractive for use in large wind farms. SkySails is already developing such a system.
“The light compact design of airborne wind energy systems means that the impact on people and the environment is minimal. The systems work very quietly, practically have no visible effect on the landscape and barely cast a shadow”, explains Stephan Wrage, Chief Executive Officer of SkySails Power. He believes that these benefits can further increase acceptance for wind energy systems: “this makes our SkySails technology an exciting alternative to traditional renewable wind power generation.”