Rotors "powered by the wind"
Actually, that's pretty much how a gyroplane/autogyro works.
To quote Wikipedia...
"An autogyro is characterized by a free-spinning rotor that turns because of the passage of air through the rotor from below. The vertical (downward) component of the total aerodynamic reaction of the rotor gives lift for the vehicle, and sustains the autogyro in the air. A separate propeller provides forward thrust".
Biting the hand that feeds IT
