Denmark-based energy company Ørsted has developed a new, lower-noise installation method which has been successfully tested at the Gode Wind 3 offshore wind farm in Germany. This technology reduces noise levels during foundation installations, enhancing protection for marine life.
The method involves a patented jetting technology attached to the monopile, which reduces the resistance of the surrounding sandy soil, allowing the foundation to sink into the seabed. This approach completely replaces conventional pile driving methods. Tests showed a substantial decrease in underwater noise levels, with a reduction of 34 decibels, achieving noise levels over 99% lower than traditional methods, just above ambient noise levels in the German Bight in the North Sea.
Beyond noise reduction, the technology promises more efficient and cost-effective installations of offshore wind foundations. 11 MW wind turbines have already been installed on the foundations at Gode Wind 3, which is expected to start commercial operation later this year.
Patrick Harnett, Executive Vice President and Chief Operating Officer at Ørsted, said, “Once industrialised, it could not only be cheaper, faster, and far quieter – without additional mitigation – than any other monopile installation technology, it also has the potential to make next-generation foundations lighter as they won’t need to be designed for the conventional installation process.”
This is the first time that jetting technology has been used to install full-size monopile foundations. Ørsted collaborated with Jan De Nul Group, using their installation vessel Les Alizés, and contractor Aarsleff. Ørsted has been developing the technology for years and is now exploring its feasibility in more complex ground conditions and obtaining further regulatory approvals for global implementation.
For the successful implementation at Gode Wind 3, Ørsted will receive subsidies from the German Federal Network Agency (BNetzA) under the Offshore Wind Energy Act, aimed at driving innovation in offshore wind development.