Wave radar calculates the forces at sea

Some 80 wind turbines are to be erected in the North Sea to the west of Sylt. A technical challenge, because such an offshore wind farm is not only exposed to waves and weather, but itself also influences the wave patterns. To examine this question, GKSS scientists headed by Dr. Friedwart Ziemer and experts from the Technical University of Saint Petersburg have developed a radar system with which the waves can be measured more precisely. “With radar devices built especially for us, we can try to monitor how big waves form, what forces they develop in the process and how these waves overlap,” reports Ziemer. At the research platform FIN03 off Sylt at the future site for the offshore wind farm, Ziemer and colleagues have already installed a permanent radar device. The FIN03 platform is coordinated by the Fachhochschule Kiel and will also be used as a permanent station within the overarching metrological network COSYNA (Coastal Observation System for Northern and Arctic Seas). COSYNA was initiated by the GKSS Research Centre Geesthacht in order to study the state and development of the North Sea.

In autumn 2009, Ziemer and colleagues will sail round FIN03 on the research vessel Friedrich Heincke with two more Doppler radars on board to measure what turbulences the platform itself generates and to what extent the current and swell affect the platform. The results can be taken into consideration in the design of the offshore wind farm as a whole, where many platforms stand in rows, and hence, turbulences can certainly build up. We do not yet know how strong these effects can be and whether they already have to be taken into consideration when designing wind farms at high sea. However, we will be able to say something about this at the end of 2009,” believes Ziemer.