A wind generator system with a plurality of lightweight, surface area adjustable airfoil/sail blades. Each blade is triangular or wedge shape with a narrow inner edge and a wide outer edge. Each blade includes an inner frame connected to a rigid mast that extends radially from a hub assembly. Each blade includes a curved outer skin layer that extends over the inner frame and configured into air foil shape with a large curved leading edge and a thin trailing edge. The outer skin layer is secured along its leading edge and removeably attached along its trailing edge to the inner frame. Coupled to the outer skin layer is a first linear actuator that when activated, causes the outer skin layer to fold or unfold thereby changing the blade's surface area. The internal frame may include a second linear actuator and a telescopic mast over which the blade slides to increase or decrease the sweep area of the blades. Wind or electrical sensors are coupled to the mast and the retractable cable to automatically control the sweep area and the surface areas.