Ørsted has developed a lower-noise method for installation of offshore wind foundations.
The technology, already proven at the new German offshore wind farm Gode Wind 3 in the North Sea, could support development of the next generation of monopile foundations, the company claimed.
At Gode Wind 3, Ørsted has tested the noise mitigation technique during the installation of three monopile foundations as an alternative to conventional pile driving. It involves attaching a patented jetting technology to the monopile, and this lowers the resistance of the surrounding sandy soil, allowing the foundation to "sink" into the seabed.
The results to date have been a substantial drop in underwater noise levels, with a reduction of 34 decibels compared to the more commonly used installation methods.
Without additional mitigation measures, noise levels were reduced more than 99% to just above the ambient noise encountered in the German Bight region.
Once the technology is adapted at scale, it could also lead to more efficient foundation installations for monopiles, Ørsted added, with 11-MW wind turbines already set down on top of the foundations.
Gode Wind 3 is due to start commercial operations later this year.
Ørsted performed the installation with Jan De Nul Group and its installation vessel Les Alizés and the contractor Aarsleff. The company now plans to assess the feasibility of applying the technique to more complex ground conditions than the pure sand conditions at the Gode Wind 3 site.
However, regulatory approvals will be needed before the technology can be implemented elsewhere.
