One possibility of alternative energy is the muscular power. Here the muscular strength of seven persons is taken together. They sit communicatively on bicycle saddles in a circle and are each connected via a freewheel with the driving wheels. They can, but must not pedaling.
In the homely circle only one person sits directly in direction of the traffic. He has a steering wheel and a parking brake or foot brake at his disposal which makes him responsible for the hopefully accident-free journey. The latter should probably not be required of somebody who is seated against the direction of the traffic. 06/08