A New Design of Blade for Small Horizontal-Axis Wind Turbine with Low Wind Speed Operation

In Thailand, the average wind speed throughout the country is comparatively low for normally-available wind turbine. Designing of a new blade suitable for applications in the average wind speed of 3-7 m sec^-1 is, thus, a main objective of this study. High torque has to be obtained properly to generate electricity. In order to design and evaluate performance, our mechanical model has been developed based on Blade Element Momentum theory and, the model is consequently employed to determine the optimized blade shape under constrains that are rotor diameter of wind turbine is not higher than 3 m, design wind velocity is 6 m sec^-1, 12 and 24 V battery chargers respectively. New wind turbine blade manually made from fiberglass (GRP) with safety factors of 4 (for 12 V battery) and 2.8 (for 24 V battery). Experimental study is conducted by testing both of commercial blades and our new blade with a specific wind turbine set. We found that, at designed wind velocity, the efficiency of our new wind turbine blade of 27% is obtained while that of the commercial wind turbine is only 16%.