German offshore wind developer EnBW and turbine developer aerodyn have commenced tests in the Baltic of the latter’s Nezzy² floating wind turbine
The turbine is being tested at sea for the first time in Greifswald Bay. The 18-m high, 1:10-scale prototype of the Nezzy2 consists of two wind turbines on a floating platform manufactured from precast concrete elements.
The floating foundation is designed to align itself with the wind direction and is moored using six chains to anchors on the seabed. Two towers rising in a V formation from the centre of the foundation support the turbines.
aerodyn already successfully tested a 1:10-scale version of the Nezzy concept, using a single turbine, offshore Japan. Nezzy2 is an improved design, and has two rotors which double the output per foundation. Using two adjacent rotors means the point of attack for the wind is lower than with a single, large rotor, which provides greater stability.
EnBW head of wind and marine technology Hannah König described the potential of floating wind as “huge.”
She said the technology will open up new areas and new countries to offshore wind.
“As well as supporting their development, EnBW also plans to deploy the floating turbines,” she explained. “France especially is an attractive market for us,” she noted.
aerodyn managing director Sönke Siegfriedsen said, “We are confident that Nezzy² will enable the international offshore wind industry to generate wind power at sea even more cost-effectively.”
Prior to the tests in the Baltic, the turbine was tested for three months in a flooded gravel pit near Bremerhaven. It has now been anchored to the seabed approximately 650 m off the port of Vierow.
The companies now plan to examine how the floating turbine performs in wind and waves. If the Baltic trials are successful, a full-scale version of Nezzy² will be put through its paces in China in late 2021 or early 2022.