On the inner layer of air filled ball (e.g. used for soccer , basket ball etc.), install piezoelectric generator and connect to battery within the ball. Extend battery output terminals to outer layer of ball for power withdrawal at will.
As the ball is kicked/bounced/caught, its minor deformation due to impact will generate power. Of course, laws of physics will be obeyed and energy would be spent by the players in the process but it would be unnoticeable.-- vedarshi, Nov 29 2006 Why the bones? This would work wouldn't it?
Course, whether it's useful or not is another question, but this is the HB dammit.-- BunsenHoneydew, Dec 04 2006 Needs to do more ie If all the football players in the UK were packed into a giant room kicking these balls around, would there be enough electricity generated to hook up to the national grid? (waits for quality of answer before voting)-- xenzag, Dec 04 2006 [xenzag] Enough power to hook to the national grid ? Thermal power-baked; hydro power-baked; nuclear power-baked. I think the list would be pretty long & anybody reading my idiotic idea would only waste time. Right ?
Specially for you, I have a modified version. Put piezo generator system behind the target plate or board or whatever you call in a shooting arena. Make the target flexible to be able to generate piezo power when the bullet strikes. I think there would be plenty of kinetic energy in the bullet. And will you spend any extra energy in the process ?
Still not satisfied ? Make the (first) target plate easily penetrable and mount a robust turbine wheel just behind the plate. After passing through the (first)target plate, the bullet will strike the turbine wheel. Will there be enough power generation compared to solar cell or piezo generator if 1000 bullets strike in 24 hours ?
Please calculate. It would be interesting to know.-- vedarshi, Dec 05 2006 [xenzag] still want better quality answer for voting ?-- vedarshi, Dec 06 2006 random, halfbakery