Retractable rotor blades for power generating wind and ocean current turbines and means for operating below set rotor torque limits

摘要

A wind or water flow energy converter comprising a wind or water flow actuated rotor assembly. The rotor comprises a plurality of blades, wherein the blades of are variable in length to provide a variable diameter rotor. The rotor diameter is controlled to fully extend the rotor at low flow velocity and to retract the rotor as flow velocity increases such that the loads delivered by or exerted upon the rotor do not exceed set limits.