Consortium to develop noise-mitigation system for floating offshore windfarms

The partners in the consortium – Chantiers de l’Atlantique, EDF Power Solutions, Heerema Marine Contractors, Menck, RTE, Sealence and Smulders – said that, although noise mitigation systems have already been developed, they want to introduce advanced technology that can minimise the potential impact of noise from installation projects for floating windfarms in deep water.

The objective of the Searénité project is to adapt the ‘SubSea Quieter’ concept, a technology designed to reduce underwater noise in other applications, to the specific requirements of installing anchors for floating wind turbines and foundations for offshore substations.

Developed and patented by Sealence, SubSea Quieter uses flexible panels made from an air-inflatable membrane. The panels would be deployed underwater around offshore foundations during their installation, acting as an acoustic shield to reduce underwater noise.

“The result is effective noise reduction through a simple, economical, and ecological solution adapted to deepwater installations,” the consortium said. “This represents a major technological advance toward sustainable coexistence between energy development and marine biodiversity preservation.”

Once installed around a foundation, with the membranes filled with air, the patented noise abatement system significantly attenuates the noise transmitted from installation operations. The 3D structure of the membrane and a specially formulated coating ensure a very high level of effectiveness.

The consortium said the first 12 months of the project will focus on adapting SubSea Quieter for anchors for floating wind turbines, offshore substations and wind turbines with jacket-type foundations. This phase of the project will include design work, acoustic modelling and analysis of hydrodynamic behaviour under wave and current conditions. Pressurised tank tests will be used to validate acoustic performance to a water depth of 300 m.

Subsequent work will include prototype production and testing in 2028 at the Port of Saint-Nazaire. Subject to successful evaluation, a full-scale demonstration project is foreseen during the installation of an offshore substation. 

The Searénité project has been awarded a grant of €7.1M (US$8.2M) and is being funded by the French State as part of ‘France 2030,’ which is administered by ADEME.