Review of savonius wind turbine design and performance

The world adopts a policy of energy transition, which refers to the substitution of fossil fuels by renewable energies to reduce CO2 emission, however the major issue is to develop a wind turbine which has a simple design, a relatively low operating speed and independent wind directions, the savonius rotor appears to be promising for such conditions, but suffers from major drawbacks: low efficiency and high negative torque.so far several scientific researchers aims to improve the performances of savonius turbine, by optimizing the effects of different geometric parameters and by developing new design. The range of the power coefficient values for the conventional Savonius rotors is between 0.1 and 0.25. The installation of several extra set leads to new designs which achieve an improvement in the coefficient of performance of 27.3% compared to the conventional rotor.