The average seawater temperature off the coast of the Japanese island of Kurahashi is 10 °C. Here, in Hiroshima Bay, aerodyn engineering is currently testing a floating wind turbine that independently aligns itself in the direction of the wind. Three thin floats keep the structure that has a total weight of three metric tons afloat on water. Two rotor blades that span over 16 meters have been installed on the eight-meter-high tower.
"The turbine delivers an output of five kilowatts with good wind conditions. However, this is just a model in scale 1:10. The full-size turbine will weigh about 3,000 metric tons and generate up to six megawatts power later, " explains Martin Bode, Senior Chief Engineer at aerodyn engineering. Six steel cables fixed to six anchoring points at the bottom of the sea are used to stabilize the wind turbine in its position. The swivel joint, where the anchoring cables meet, allows the entire turbine to freely align itself according to the direction of the wind. It is important for the tests to determine the stress to which the turbine’s anchoring system is subjected. “Whether they are exposed to heavy storms or high waves, the wind turbines anchors need to withstand extremely rough conditions in the long term later. It is therefore essential to our measurements to use extremely robust force transducers that can be used underwater for several months, "says Martin Bode. The sensors also need to provide very precise and detailed results to enable dependable data for the full-size turbine to be derived from the model test.
“We need reliable testing and measuring equipment for the complex testing of our new offshore wind turbine. The S9M force transducers provide reliable and very precise data about the tensile loading of our anchoring system, even in extremely harsh conditions at sea,“ says Martin Bode, Senior Chief Engineer at aerodyn engineering.