A numerical study of horizonal axis wind turbine blade contamination: aerodynamic and sustainable impacts

Wind turbine blade contamination, particularly on the suction side, can significantly degrade aerodynamic performance and reduce output power, making it essential to understand its effects for efficient wind energy generation. This study investigates the influence of varying contamination extents on the aerodynamic performance of horizontal-axis wind turbine blades and quantifies the resulting environmental and economic impacts. To analyse these effects, computational fluid dynamics simulations were conducted at two Reynolds numbers under both clean and contaminated blade conditions. This was followed by a blade element momentum analysis to assess annual energy production. The results show that contamination increases drag, reduces lift, and shifts the transition onset upstream, thereby decreasing aerodynamic efficiency. The blade element momentum analysis confirms that greater contamination extent up to 10 % reduces annual energy production, contributing to higher carbon emissions and economic losses exceeding 7 % relative to the minimum contamination extent.