Abstract: A Savonius three bladed vertical axis wind turbine rotor has operational characteristics superior to those of conventional three bladed rotors. The blades have high curvature and a high skew factor, for example a curvature of greater than 7:1 (e.g. 2:1-5:1), and a skew factor of greater than 0.6 (e.g. 0.78-0.9). The rotor also includes at least one vertical shaft, the blades operatively connected to the shaft. The rotor typically has an aspect ratio of at least 2:1. The rotor typically has a maximum power coefficient (Cp) of at least twice that of an otherwise identical rotor with a skew factor of 0.5 or less. The rotor can drive a generator with a drive which automatically increases the effective gear ratio as the rotational speed of the rotor increases; or the rotor can be connected to a propeller of a multihull wind powered boat.

Abstract: A Savonius three bladed vertical axis wind turbine rotor has operational characteristics superior to those of conventional three bladed rotors. The blades have high curvature and a high skew factor, for example a curvature of greater than about 7:1 (preferably at least 5.5:1, e. g. 2:1-5:1), and a skew factor of greater than about 0.6 (preferably at least 0.7, e. g. about 0.75-0.9). Preferably the rotor also includes at least one substantially vertical shaft, the blades operatively connected to the shaft. The rotor typically has an aspect ratio of at least about 0.8:1, preferably at least about 2:1 (with the aspect ratio of each blade about twice that of the rotor). The blades desirably comprise a plurality of substantially aligned spokes axially spaced along the shaft each spoke comprising three generally radially extending ribs arcuately spaced from each other approximately 120 degrees.