A numerical case study of the impact of wind farm wakes on ocean surface waves in the Baltic Sea

Abstract This study presents a case study of the impact of wind-farm wakes on ocean surface gravity waves in the Baltic Sea based on the sensitivity simulations of a typical diurnal cycle. The results indicate notable decreases in significant wave height (Hs). In the region immediately behind the wind farm, Hs reductions of up to 21% were observed, with a mean daily reduction of 12.54%. The effect was diminished but still noticeable several kilometres downwind, with a decrease of up to 5.85% and a mean reduction of 2.63% of Hs 80 km downwind. Changes in mean wave period and direction were minimal, indicating that the primary impact is on wave amplitude. The results indicate that offshore wind farms can significantly impact ocean wave characteristics due to wind speed deficits caused by turbine wakes.