Today, the main goal of wind energy industry is to minimize the cost of wind energy in order to make it more competitive compared to other energy sources. How to reduce the cost of wind energy is a vital engineering challenge presented by the interlocking disciplines of aerodynamics, structure, control, electrical conversion, and electronics. In fact, technologies in these related areas are still under active research and development to achieve high efficiency and low cost.
Upon this basis, responding to more demand in coming years, the task of the low-sized wind energy industry requires progress on several fronts—the public policy initiatives, technology development, and market growth. One important issue of the wind energy utilization is the conversion efficiency of the usable energy into productive power. Enhanced technologies such as contrarotating blades, gearbox and lubrication, airfoils, generators, and power electronics will lower cost and increase energy production. The purpose of this paper is, therefore, to reinforce the effectiveness of employing contrarotating system to enhance the performance of a low-sized wind energy converter (LWEC). With this concept, the LWEC works more efficiently and therefore produces more energy in a unit turbine area. To verify the LWEC performance, a research model has been built and tested over a range of operating conditions. Wind tunnel tests were carried out to ascertain the overall performance of the contrarotating LWEC. Results are presented for cases of different wind speeds and Reynolds number. The results demonstrated a significant increase in wind energy conversion efficiency and capability of operation at lower wind speeds while keeping up performance compared to a single-rotor system of the same type.