Wind Energy Conversion Systems as a Distributed Source of Generation

As a result of the worldwide energy crisis, research and development activities in the field of wind energy have been gaining momentum for the last few years in many countries. Although this technology has been greatly improved during that time, the available technical know-how is not yet adequate to develop reliable wind energy converting systems for Indian conditions at low wind speeds. In spite of a few indigenous efforts, the developments of wind energy converting systems working at low wind speeds of 2–5 m/s, which is available for a considerable period of the year in the major part of the country, remain unfulfilled. This issue continues to be a matter of great concern for the Indian researchers. This paper introduces a new concept of amplifying the wind speed before it comes in contact with the rotor blades of a Savonius turbine by using a convergent nozzle. This novel work emphasizes the improvement of the efficiency of Savonius rotors, which normally extract less than 25% of the power in the wind and have been commercially unsuccessful. A research program involving wind tunnel tests of five different nozzle models has been conducted. Some necessary modifications in the design of the turbine have been suggested and verified practically with the help of working models. Analysis of different nozzle dimensions has also been outlined. The variation of the output speed with different values of input wind speed and different lengths placed at different distances from the wind tunnel are presented in the paper.