2012 - Noise reduction during installation of wind turbines

According to legislation from the EU, sound emissions from the installation of windmills at sea must be reduced so the threat to marine mammals is minimised. Until now, no efforts have been made to reduce the water borne noise from driving monopiles into the seabed. With a new and innovative technology, it is possible to reduce the noise by up to 25 dB in a radius of 750 m. The technology is based on a cofferdam (patent pending), which complies with the recommended requirements of maximum: 160 dB SEL and 190 dB Peak for underwater pile driving noise levels. So far, Germany is the only country to have ratified the legislation, but the remaining EU countries are expected to follow Germany’s example.

The technology is developed by Lo-Noise, founded in cooperation between Kurt Thomsen, creator and founder of A2SEA (world leader in installation of offshore wind turbines), and OSK-ShipTech A/S (consulting naval architects with extensive experience in offshore wind projects).

The visionary thinking enables an installation process almost without delay as well as ensuring that the costs do not increase significantly by using the cofferdam from Lo-Noise. In Europe, the preferred foundation for offshore wind turbines is monopiles, which could result in an industrial adventure for Lo-Noise and their new noise reduction technology.

From the 15th to the 20th of December, the cofferdam was tested in the bay of Aarhus, Denmark with very positive results. The cofferdam is the only technology that lowers the noise level by 25 dB and meets the requirements of the EU legislation. The cofferdam test was performed together with the following companies: Grundfos, Trelleborg, NICON Industries A/S, DBB, Rambøll and OSK-ShipTech.