[mbreese]

I don't know anymore than what was on their site, but my reading of it was that it works by moving the airframe (plane? glider?) around in the wind-stream. The tether would then be continuously moving back and forth (or in and out). I think this the meaning behind the figure-eight pattern they show.

If it's anything like some ocean wave generators, it might be able to generate power when moving in either direction, but I'm not sure about that.