DESIGN AND CONSTRUCTION OF A 4 KW GROUNDSTATION FOR THE LADDERMILL

This paper presents the design of a 4 kW Laddermill groundstation. The Laddermill is a novel concept to harvest electricity from high altitude winds. The concept’s operating principle is to drive a generat or with kites. Several kites are high in the air at an altitude of more than 1 km. All kites are connected to a sin gle cable that connects to a drum in the groundstation. The lower part of the cable is connected to the kites a nd is wound around a drum. The kites pull the rope from t he drum, which in turn drives a generator. When all of the cable is pulled off the drum, the kites fly down in a configuration that generates significantly less lif t than during the ascent. This way the lower part of the t ether is retrieved onto the drum and the process is repea ted. The concept allows very large single unit power. At Delft University of Technology, a 2 kW test model o f the Laddermill was constructed and tested successfu lly. From this 2 kW Laddermill several valuable lessons were learned. Taking the lessons learnt into accoun t, a 4 kW groundstation was designed.

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