Mr. Ken Sulman's Savonius Rotor, the Alternative Windmill is a good tutorial about Savonius Rotors and their practical applications. This one has an automotive differential attached, pumping water for his fruit orchard, and could be used to drive a multitude of machinery. The pictures take a while to load but it's well worth the wait! Remember, Savonius Rotors are high torque, low speed turbines, and simple to construct.
Offered by Jay.