The strategy for the use of wind power in urban areas by hybrid vertical axis wind turbines

Using wind turbines in urban areas is one of the most challenging issues in using wind energy. due to the complex structure of urban areas, the fluid flow turbulence and the change in wind speed in these areas is significant. It is common that vertical axis (Darrieus-Savonius) wind turbines in that operate independently of the wind direction is commonly used. In this research, a comprehensive overview of major studies in this area has been carried out. In addition, challenges of using a variety of vertical axis wind turbines are mentioned. on of the challenge in this topic is using a hybrid wind turbines, with two types of Darrieus and Savonius. Darrieus turbines have high power coefficient, While Savonius turbines have the ability to start very well even at low wind speeds. In this research, it has been studied to make this system more functional and some suggestion have been presented. In order to eliminate the destructive effect of the Savonius turbine rotor on the Darrieus turbine rotor at high wind speeds, a mechanical clutch is proposed for separating these two rotors at high rotational speeds.