Analysis into cost of additional underwater noise mitigation during offshore wind farm construction

Increases in offshore wind development are needed to meet the government's target of 40GW by 2030, however construction of these developments has the potential to harm the marine environment. Marine mammals are sensitive to this noise, which has the potential to kill, injure or disturb without appropriate mitigation. A key area of concern is impulsive noise, primarily generated when installing turbine foundations. Developers are already required (as part of the consent process) to implement marine mammal mitigation when undertaking these activities, however, it is anticipated that additional mitigation will be needed in the future to reflect increases in the size of turbine generators and their associated foundations; and to manage in-combination effects, which are a major concern given the number of developments required over the next ten years. Defra and BEIS are working together to investigate how additional noise mitigation could be used to substantially decrease the amount of underwater noise produced during offshore wind farm construction, and whether the requirement for mitigation should be mandatory. This proposed project is aligned with a Defra project. The Defra project will review existing regulatory processes for offshore wind and consider how piling can be managed and mitigated. It will also summarise available noise reduction options and consider what mitigation may be needed in the future. The BEIS project will review the cost implications of this additional mitigation.