The human body can deliver enough power to drive computers, television sets and washing machines – but it does go hand in hand with lots of sweat.
Eco-tech boffins dream of self-sufficient gadgets: mobile phones fed by solar energy, heartbeat-powered music players. However, the potential of these energy sources is much too small. Handles, cranks and biking machines on the other hand, do have a promise to be a powerful energy source. Swinging a crank for fifteen minutes is enough to power a mobile phone. Less than an hour of pedalling a bike can power larger machines. The only thing missing is a remedy for laziness.
