Abstract
The growing demand for offshore wind energy has led to a significant increase in wind turbine size and to the development of large-scale wind farms, often comprising 100–150 turbines. However, the environmental impact of underwater noise emissions remains largely unaddressed. This paper quantifies, for the first time, the underwater aerodynamic noise footprint of three large offshore turbines (5, 10, and 22 MW) and wind farms composed of these turbines. We propose a novel methodology that integrates validated wind turbine noise generation (i.e., blade element momentum theory and Amiet) with plane wave propagation theory in different media, enabling turbine designers to predict underwater noise emissions. Our results indicate that the three turbines generate underwater noise levels that exceed the hearing thresholds of the low-frequency hearing group in the range of 0.1–1 kHz. When scaled to represent wind farm conditions, the predicted noise levels may become detectable by additional hearing groups at frequencies up to 10 kHz. For the scenarios considered, the results suggest that aerodynamic noise from offshore wind farms could contribute to the underwater soundscape and may have implications for marine organisms. These findings highlight the importance of considering aerodynamic noise in environmental assessments of offshore wind energy development.