STATIONARY CO-AXIAL MULTI-ROTOR WIND TURBINE SUPPORTED BY CONTINUOUS CENTRAL DRIVESHAFT

Co-axial, multi-rotor wind turbines, producing more power than a single rotor of the same diameter, are made even more powerful by increasing driveshaft length and supporting the driveshaft from more than one point. Sacrificing the ability to aim, for the extra length to support additional rotors, results in a more powerful co-axial multi-rotor turbine, especially useful for areas with a predominantly unidirectional wind resource. Ideally the turbine is placed at an offset angle α (alpha) from the wind direction, which, in combination with proper spacing between rotors, allows fresh wind to reach each rotor, so that all rotors contribute toward rotation of the driveshaft. Placing the driveshaft under tension can raise critical speeds and reduce the number of intermediate supports required. This places the Earth or underlying substrate in compression, making it effectively part of the structure of the turbine, saving cost. Cross-axis and reversible blades may also be incorporated.