Hey Snorg,
A friend of mine built an electric trike this past summer, which he is planning on adding a bio-diesel generator to for extending range.
You can see the thread about it
here
Basically, it's the back end of a motorcycle, and the front end of an ATV. It uses a Curtis PWM (pulse-width modulation) solid-state controller for the speed control and runs at 48 volts (4 x 12V batteries)
