Abstract: A windmill blade system with two distinct blade ends with each comprising a center area having a series of identical projections equidistant from a central mounting orifice in the center area. Each of the projections consist of an upward and a downward facing triangle sharing a common base. When the blade units are combined by aligning the center areas of each, the triangles of the upper blade unit are above the plane formed by the center areas and the lower triangles of the lower base units are below that plane. With the lower blade unit projections forming a mirror image of the upper ones.The invention also contemplates a windmill having at least one of the blade systems rotating horizontally about a vertical shaft.