Dutch guitar giant Jan Akkerman, former astrounaut Wubbo Ockels and Delft University all worked together to come up with this tiny concert in the Stadspark of Groningen last year. The reason? The electrical power was delivered by a prototype of a so-called Laddermill, an invention by Wubbo Ockels that is currently being developed at the University of Delft, and that consists of a chain of kite-wings that act as kites when going up, and as wings when going down.

Laddermills should be able to deliver from kilowatts to megawatts of power, enough to provide neighbourhoods and cities with electricity. According to the Guardian, laddermills are especially useful in The Netherlands, Denmark, the UK and Ireland “thanks to the high-speed jet stream.”

If you’ve never heard of Akkerman before, check YouTube for “focus hocus pocus.”

Via Engadget. See also this TU Delft page.