Sounds like fun. :)

I remember telling my Dad when I was in high school that I thought it'd be a good idea to recapture energy from a car's turning wheels & put it back into electrical energy. (Sadly my dad thought I was trying to make a perpetual motion machine & told me it wouldn't work.) I now see electric-hybrid cars are doing this very thing to recapture some electrical energy that otherwise would be lost as the car moves.