RWE, in collaboration with Hydrotechnik Offshore, a Germany-based bubble curtain developer, has deployed the underwater noise abatement technology during monopile installation at the Sofia offshore wind farm, marking the first time the technology has been used in the UK.
Currently under construction on Dogger Bank, 195 kilometers off the UK coast, the 1.4 GW Sofia project is situated within the Southern North Sea Special Area of Conservation (SAC), a protected zone for harbor porpoises where noise disturbance regulations are strictly monitored, RWE says.
The bubble curtain reduces the propagation of underwater noise during piling operations and mitigates disturbances to marine species, such as harbor porpoises, dolphins, and whales, which rely on ultrasound for orientation.
The technology has already been used on several offshore wind projects, including Vattenfall’s DanTysk wind farm offshore Germany back in 2013.
The bubble curtain system was also deployed at EnBW’s He Dreiht offshore wind farm in Germany last year, as well as the Vineyard Wind 1 project in the United States.
The noise abatement system involves a perforated hose placed on the seabed around the installation site to form a 180-meter-wide ring. Compressed air is then pumped through the hose, generating a continuous stream of bubbles that rise to the surface. This bubble barrier effectively breaks up and slows down the sound waves, significantly reducing noise levels during piling operations, RWE explains.
The monopile foundations at the Sofia project site are being installed by Van Oord using its jack-up vessel Aeolus.
In March, more than 60 out of the 100 wind turbine foundations were in place, with the first wind turbine also installed by Cadeler’s new vessel Wind Peak.
The 1.4 GW offshore wind farm is expected to be commissioned in 2026, when it will be capable of generating enough electricity to power the equivalent of 1.2 million UK homes.