RWE and Hydrotechnik Offshore have deployed an underwater noise-abasement technology for the first time in the UK to protect marine life from offshore wind construction noise at the Sofia project.
The technology, known as a bubble curtain, was deployed at the 1.4GW Sofia offshore wind farm, located 195km off the coast of England.
The bubble curtain, which has already been adopted across Europe, reduces the propagation of underwater noise by creating a barrier of rising bubbles around the turbine installation site.
By dampening sound waves, the technology mitigates disturbances to marine species such as harbour porpoises, dolphins, and whales, which rely on ultrasound for orientation.
The system works by placing a perforated hose on the seabed around the turbine installation site, forming a 180m wide ring.
Compressed air is pumped through the hose, generating a continuous stream of bubbles that rise to the surface.
RWE said it is this bubble barrier which effectively breaks up and slows down the sound waves, significantly reducing noise levels during piling operations.
The Sofia project is situated within the Southern North Sea Special Area of Conservation (SAC), a protected zone for harbour porpoises, where noise disturbance regulations are strictly monitored.
Sofia project director at RWE Matthew Swanwick said: “By introducing the use of a bubble curtain on a trial basis, we are strengthening our commitment to environmental responsibility.
“Projects like this can ensure offshore wind energy can be developed sustainably, with minimal impact on marine life, taking cognisance of working with a Special Area of Conservation.”
Sofia offshore wind farm is pioneering sustainability through several initiatives, including using recyclable wind turbine blades.
Half of Sofia’s 100 turbines will be equipped with recyclable blades, the highest proportion ever implemented on a major wind farm.
In addition, the project will utilise two of the world’s first methanol- and battery-powered Service Operations Vessels, reducing carbon dioxide emissions by up to 10,000 tonnes annually.
The Sofia project has also made donations including a £25,000 contribution to North Sea Conservation, the charity behind the Whitby Lobster Hatchery.
The Sofia offshore wind farm, currently under construction on Dogger Bank, will comprise 100 Siemens Gamesa 14MW offshore wind turbines.
Upon its commissioning in 2026, the project will have a capacity of 1.4GW, enough to power the equivalent of 1.2 million typical UK homes.