Some aspects of vertical axis wind turbines [VAWTs]-a review

Energy is an essential ingredient in the socioeconomic development and economic growth of any country. Energy is available in two different forms, nonrenewable [coal, fuel, natural gas] and renewable [solar, wind, hydro, wave]. Wind energy is the most abundantly available clean form of renewable energy. The impetus for the continual harnessing of wind energy across the world arises in reaction to the fast depletion of the reserves of conventional fuels and the danger of global warming due to greenhouse gas emissions. Wind energy is utilized for a variety of functions ranging from windmills to pumping water and sailing boats. Vertical Axis Wind Turbines [VAWTs] would be appropriate for tapping into low speed wind to produce power in a smallscale manner, which would be useful in remote places where electricity is scare, especially in developing countries. However, VAWTs are not gaining in popularity due to their low power coefficient,hence the need for research in this area to enhance the performance of VAWTs. In this paper, some aspects of VAWTs, such as design and performance have been reviewed with regard to Savonius, H-Darrieus and combined Savonius-Darrieus turbines.