Abstract: A vertical axis wind turbine comprising at least two rotor portions, each portion having a bottom, a top, and a curved horizontal cross section when seen in top view. A top cap may be provided that has a convex portion corresponding to each rotor portion that extends forwardly in a windward direction. Each rotor portion may comprise two angled rotor sections that meet at substantially a vertical midpoint of the rotor portion. The angled sections may be angled rearwardly in a leeward direction and/or radially and may be angled from 1 to 20 degrees with respect to vertical. There may be three or more rotor portions and the turbine may be comprised of one or more vertically stacked sections.

Abstract: Provided is a wind powered system for reducing energy consumption of a power source, such as an internal combustion engine or an electric motor. In one embodiment, the wind powered system comprises a wind turbine operatively connected to an internal combustion engine, for example via a direct mechanical connection, a hydrostatic drive system or a pneumatic drive system in order to reduce the amount of fuel required by the engine to operate an electricity generating means. A controller may be optionally provided to modulate the load on the wind turbine in order to maximize the extraction of available power according to local wind conditions. In another embodiment, the wind turbine is connected to an air compressor for providing a supply of air in order to offset energy consumption of a conventional compressed air system.

Abstract: A vertical axis wind turbine comprising at least two rotor portions, each portion having a bottom, a top, and a curved horizontal cross section when seen in top view. A top cap may be provided that has a convex portion corresponding to each rotor portion that extends forwardly in a windward direction. Each rotor portion may comprise two angled rotor sections that meet at substantially a vertical midpoint of the rotor portion. The angled sections may be angled rearwardly in a leeward direction and/or radially and may be angled from 1 to 20 degrees with respect to vertical. There may be three or more rotor portions and the turbine may be comprised of one or more vertically stacked sections.

Abstract: A vertical axis wind turbine comprising at least two overlapping rotor portions, each having a curved or semi-circular horizontal cross-section, each rotor portion having an outer leading edge that is angled relative to vertical from bottom to top in the direction of rotation of the wind turbine. The magnitude of the angle is in the range of from 5 to 30°. The angled leading edge improves aerodynamic performance of the wind turbine relative to the absence of the angle, particularly for turbines with three or more rotor portions.