Enhancing the Performance of Savonius Wind Turbines: A Review of Advances Using Multiple Parameters

The need to globalize and implement the fourth industrial revolution has led to increased interest in research on renewable energy harvesting equipment. Wind and solar have been the fastest growing sources of energy and have been used to reduce our dependency on fossil fuels for energy. The Savonius wind turbine is an attractive option for regions with high turbulence intensity and low wind speeds due to its advantages over other small-scale vertical-axis wind turbines. These advantages include its simple design, satisfactory performance at lower speeds, and ability to turn independent of the wind flow direction. However, Savonius wind turbines face several challenges. The most significant one being the negative torque generated during operation. This negative torque is caused by the interaction between the exhaust air and the returning blade, thus reducing efficiency, as the turbine has to overcome this additional force. To improve on the efficiency, various assessments and optimization techniques have been employed. These focus on the geometric parameters of the Savonius wind turbine as well as installation augmentation techniques. This article reviews and reports on several combinations of parametric performance-influencing adjustments and power augmentation techniques applied to Savonius wind turbines. The article concludes by proposing future research directions.