the frame 2 in a substantially vertical position though it will be appreciated that the wind turbine could be operated about any axis in the preferred embodiment where there are multiple vane layers 6 each vane layer is offset radially from its neighbor to form the desired helix for efficiency of manufacture reduced waste in cutting each vane layer may be formed from three vane sections secured to a central hub not shown or as in the illustrated and preferred embodiment one of the vanes has an integral hub portion 10 to which the other vanes are secured see fig5 and 14 each vane layer is positioned by virtue of dowel pins 12 in holes 13 which are offset from each other sufficiently to produce the desired offset preferably especially for larger wind turbines each vane layer 6 may have one or more cavities 18 to reduce the overall weight preferably in such an arrangement the top and bottom vane layers are not provided with these cavities so that there is no opening into the interior of the vanes in smaller designs i e where the weight of the assembled body is less of a concern it may be unnecessary and or preferable to avoid such cavities preferably in the three vane preferred embodiment each vane is offset by a total of 120 degrees from top to bottom i e there is 120 degrees of u201c twist u201d as shown in fig4 and each layer is u00be inches in thickness the desired height of the overall wind turbine therefore determines the necessary offset.