Effect of rotor length on generating power in horizontal axis wind turbines

The benefits of the rotor design are optimizing power generation and reducing cost of build in wind turbines. In this study, a performance comparison of horizontal axis wind turbines in terms of their rotor diameter is made using Qblade software. The airfoil selected is the National Advisory Committee for Aeronautics (NACA 0012) for all models, and the wind turbines have three blades. From simulations, the optimal rpm for each rotor diameter was calculated, and the generated power for different wind speeds. The results found show that the operation of wind turbines consider need operated with tip speed ratios of between 4 to 7 to give optimal power output. Maximum power was produced for a blade diameter of 170 metres and the highest power coefficient found was for a diameter of 30 metres and for this case also had the highest tip speed ratio of 6.68. Overall results can suggest which diameter range is used for choosing a rotor size that is the most cost-effective.