Aerodynamic optimal blade design and performance analysis of 3 MW wind turbine blade with AEP enhancement for low-wind-speed-sites

The annual average wind speed in more than 80% of the global area that can potentially be employed for onshore wind farm development is lower than 7 m/s. Onshore wind farm development has been accomplished in most regions with excellent wind resource. Based on the increasing need for onshore wind farm development in low-wind-speed sites owing to the effect of environmental factors, commercial demand of IEC-Class III wind turbine has significantly increased among the world's leading developers and wind turbine manufacturers of the wind power industry. Thus, aerodynamic design of a 3 MW wind turbine blade for low-wind-speed sites was performed in this study. The geometry was optimized to improve AEP (Annual Energy Production) and minimize the increasing rate of thrust. The performance analysis result by Blade Element Momentum method showed that the increase in thrust was limited to less than 5% and AEP was enhanced by 20% at annual average wind speed of 7 m/s compared to the reference blade. To verify the final aerodynamic design result, CFD simulation was performed. It was confirmed that AEP was increased by 15%, and the increasing rate of thrust was found to be 5.1% at the same annual average wind speed.