Effect of Solidity on Power Performance of Vertical Axis Wind Turbine

Wind energy is one of the potential renewable energy sources and a great alternative to replace conventional power generation using coal and fossil fuel that heavily contribute to climate change. Recently, small scale vertical axis wind turbine (VAWT) has received growing interest as wind energy converter due to its suitability to be used in low wind speed area. Hence, this paper is intended to evaluate numerically the effect of solidity, by varying turbine diameter, on power performance of VAWT using computational fluid dynamic (CFD) technology. A series of two-dimensional CFD simulations was performed on a three-bladed H-type Darrieus rotor equipped with symmetrical NACA0018 blades. Performance evaluation on 3 turbine configurations with different diameter; i.e. 1.0 m, 0.6 m and 0.43 m were performed over a range of tip speed ratio, λ with an incoming velocity of 8.0 m/s. The simulation results clearly show that low solidity turbine performed better at high values of λ and has wider operating range while turbine with low solidity performed better at low λ and has better self-starting capability. The results lend substantially to our understanding of solidity effect on performance of VAWT in order to develop an ideal design of VAWT that can operate optimally in complex wind condition.