Handlebar Grips Project. Help needed!

Hi guys,

I'm currently doing a major project for my Industrial Design course. I've come up with this idea of heated handlebar grips for bicycles, it's very early days so I'm just trying to gage how feasible this project is. My electronics knowledge is fairly limited so I'm after some guidance.

Basically I'd like the grips to be heated to a warm temperature by the actual motion of the bike through the use of dynamos and generators but I'm not sure if enough watts could be generated just through the motion of the wheel or the pedals alone. I know this works fairly well with LED lights.

The alternative to this is to charge the handlebar grips up by USB, but this is more hassle to for the user so I'd really like to make it powered by the bike even though this is probably near impossible...Any help would be much appreciated guys!