Design and improvement the efficiency of wind turbines for agricultural ourposes and electricity generation in a low-wind area

Abstract

Two models of wind turbines which were constructed according to the Axial Momentum Theory and the Blade Element Theory were composed of 3 wooden blades with 1.2 -meter length and 1.5-meter length. The experimental results showed that for the Model I, it could generate the maximum electricity 259.85 watts at 6.7 m/s and for the Model II it could generate the maximum electricity 1,680 watts at 10.76 m/s Meanwhile the Model II, at maximum speed at 10.76 m/s, it could pump water at the rate of 171 L/hr. In addition, economic worthiness analyses in terms of electricity generating cost per unit and payback period were conducted. Then they were found that for the Model I, the electricity generating cost per unit was Bht.15.63 and payback period was 38.52 years and for the Model II, the electricity generating cost per unit was Bht. 5.96 and payback period was 14.69 years. In summary, the both model of wind turbines could start electricity generating at the wind velocity at 2.0 m/s; However for the Model II, its maximum electricity power was 1,680 watts at the wind velocity at 10.76 m/s and its maximum energy efficiency was 0.33 at the wind velocity at 4 m/s. Moreover, electricity generating by a wind turbine would be interesting and worth investment if the electricity generating cost per unit were higher than Bht. 6.00.