Patent ID: 7329965

Claim:
A vertical wind turbine device, comprising: a) a rotor, rotatable about a vertical axis in an annular stator; b) a plurality of vertically elongated rotor airfoils, disposed circumferentially around the vertical axis; c) the rotor airfoils each having a horizontal cross-section with a crescent shape including a convex leading side and a concave trailing side with a thicker middle section that tapers to narrower sections at ends d) a plurality of vertically elongated stator blades, disposed circumferentially around the vertical axis; e) the stator blades each having a horizontal cross-section with a planar side and a convex side; and f) the convex side of the stator blades and the convex leading side of the rotor airfoils being oriented to face circumferentially around the vertical axis in a common direction.