Nezzy² in Hymendorf (pict. EnBW/Jan Oelker)
Two wind turbines on a precast concrete floating platform: that, basically, is Nezzy2. This 18 metre tall, 1:10-scale prototype is being tested by EnBW and aerodyn engineering, a north German engineering company, in a flooded gravel pit near Bremerhaven. Next, this summer, Nezzy2 is to prove itself in wind and wave conditions in the Baltic Sea. If these trials go well, the model is to be tested at full scale with another partner in China. The aim of the research project is to develop a new offshore technology enabling wind turbines to float on the water surface.
Until now, offshore wind turbines have been anchored to foundations in the seabed at maximum water depths of 50 metres. That limits the choice of suitable marine areas. Floating turbines change this completely: “The potential is huge. This new technology opens up countries and marine areas with greater water depths and expands the possibilities for renewable energy generation,” explains Dr. Hannah König, head of wind and marine technology at EnBW. “We are testing Nezzy2 in partnership with aerodyn because it brings together a range of technical innovations.” EnBW itself plans to deploy floating wind turbines in future projects: “France especially is an attractive market for us here together with our subsidiary Valeco.”
Aerodyn already successfully tested a 1:10-scale predecessor model with a single turbine in the sea off Japan in 2018. Nezzy2, its successor, has two rotors and has so far been tested on a scale of 1:36 in an artificial wave channel in Cork, Ireland. “We are confident that Nezzy2 will enable the international offshore wind industry to generate wind power at sea even more cost-effectively in future. In EnBW, we have gained a partner for our test with ten years of experience in the construction and operation of offshore wind farms,” says aerodyn Managing Director Sönke Siegfriedsen.