Technical Papers and Presentations

Vibration produced by offshore wind turbines during their normal operation transmits through the tower into the foundation where it interacts with the surrounding water and is released as noise. The noise produced by offshore wind turbines can be detected by fish and marine mammals and may lead to alteration of their behavior. Given that noise is emitted at the interface between the foundation and water, it is likely that the intensity and frequency of the noise will be strongly affected by the nature of the foundation. Factors that may affect the nature of the noise emitted are the surface area of the foundation, the material used to construct the foundation and its internal damping and the nature of the connection of the foundation to the sea floor. An acoustic-structural interaction model developed in COMSOL Multiphysics® was used to model the underwater sound-field around different foundation types that support a wind turbine (see Figure 1). Harbor seals, grey seals and bottle nose dolphins are not considered to be at risk of displacement by the operational wind farm modeled. It is unlikely that any marine mammals would experience auditory injury as the result of operational wind farm noise.