Delft explores kite power for rural Africa

It’s possible that at least some of Africa’s next wave of rural electricity will come from the sky.

Delft University of Technology has a program devoted to kite-based generation systems, with 20 years of research and development under their belt since Wubbo Ockels, the first Dutch astronaut, established it. Now, members of the team are exploring practical niches where kite-based power might pay off. One has just completed a trip through Kenya, Tanzania and Senegal seeking opportunities for kite generation in rural Africa.

Christopher Grete, a member of the Delft KitePower curriculum focusing on deployment of kite generation, has just returned from an extended trip through Africa where he was drumming up interest in using kite-based generation in rural Africa. This is an area typically poorly served by the national grids and with significant logistical challenges for major construction. Delft has been researching kite-based generation since 1993 when the first Dutch astronaut into space, Wubbo Ockels, established the program. The faculty has several professors and students engaged in simulating, prototyping and assessing all aspects of the field, but are just starting to seriously consider commercialization.

Innovative wind generation systems have a tendency to focus on the technology instead of a target business niche, and the Delft team is no exception. They have advanced three different types of kites over the years, including inflated tube kites similar to those used by kite surfers, inflated airplane-style kites and airfoil kites.

They have stayed with fabric kites which typically have an advantage for deployment, crashes and recovery of airborne generation while giving up top-end power to rigid wings. The inflated and airplane kites they use have greater speed and hence power advantages over airfoils, but of course depend on either ground-based repressurizing, or as yet unbuilt airborne repressurization systems. This is a similar challenge to their counterparts at TwingTec, who use a unique, inflated structural member of high-strength.

The Delft staff have tried a mixture of control systems over the years. For some of their prototypes they have used radio controls, while for others they use ground-based tether controls just as any traction- or stunt-kiter is familiar with. They have settled on an airborne, radio-controlled system positioned in the bridle of the kite that hauls in and releases the control tethers for the kites using microwinches. This increases airborne complexity, but eliminates multiple lines running all the way to the ground and multiple ground winches for control. It also allows easy depowering of the kite for the upwind pull. This is a very reasonable compromise, and the solution allows intelligence of automated control to be ground-based or in the control unit itself in the future.

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