Design and simulation of high efficiency counter-rotating Vertical Axis Wind Turbine arrays

Technology to abstract energy from the wind using Vertical Axis Wind Turbines (VAWTs) has rarely been adopted for large scale power production, owing to low power coefficient of the individual turbines, as compared to Horizontal Axis Wind Turbines (HAWTs). In the last few years, much research has been done to make VAWTs more economical and efficient to increase power generated per turbine. But besides improving coefficient of power through design changes, research now focuses on maximizing power generated per unit area. Arranging VAWTs in specific layouts of Counter Rotating Arrays can enhance power production in low wind speed areas and thus increase the W. This paper analyses Counter Rotating VAWT Arrays in terms of coefficient of power and power density and further compares efficiencies in various arrangements. The effect of angle of attack on the performance of the array has also been studied further explaining the effects of arrangements on Wind Farm Power Density as well as the Total Wind Farm Power.