Abstract: The invention relates to a wind turbine having arm members each comprising an inner and outer portion at an angle of near 90.degree.. A vane is pivotally attached to each outer arm portion and biased at a desired pitch angle to the inner arm portion. Springs are provided to allow the vanes to move toward a neutral wind position when high wind conditions threaten the integrity of the structure.

Abstract: The invention provides a wind turbine rotatable about a vertical axis comprising a plurality of planar vanes each situated along the height of a vertical shaft at a separate level. Adjacent vanes are staggered at the same dihedral angle to one another. Each vane has a plurality of doors which pivot between an open and closed position. Auxiliary panels are provided above and below each set of doors to channel the flow of air along the vane thus increasing the power derivable from the wind. Automatic release means for the doors may be provided to prevent structural damage under high wind conditions.