For the development and construction of offshore wind farms, reliable measurement data on the environment conditions on site are essential. This data is now to be delivered by a newly designed monitoring buoy, which will combine meteorological and oceanographic measurement techniques for the first time. The work of both project partners – the Federal Maritime and Hydrographic Agency (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and the Fraunhofer Institute for Wind Energy Systems (Fraunhofer-Institut für Windenergiesysteme, IWES) – comprises a real-life test as well as the design and development of the prototype.

When constructing offshore wind farms, the average wind speed at the height of the hub of the wind turbine is of key importance for assessing the yield and for the turbine design. The plan is that this data will now be supplied by the innovative buoy via an integrated LiDAR (light detection and ranging) wind measurement device. With this measuring principle, laser impulses sent from the LiDAR are reflected in the atmosphere by dust particles and recaptured by the LiDAR. The wind speed is calculated, among other things, from the propagation time difference of the light.

The oceanographic data gathered by the buoy is also intended for use in order to adapt the foundation of wind turbines to the wave loads in the best possible way in the future. As well as the current, the prototype will not only be able to measure the saline content and proportion of oxygen in the water, as well as its temperature; the collection of information about nutrients, the ph value and on radioactivity is also planned in the water bodies being tested.

The monitoring buoy is designed to supply the data in quasi-real time, and is designed for both continuous measurements and flexible use. As well as a better assessment of the wind potential for the offshore wind industry, the data is also helpful for meteorologists when predicting the weather, or for monitoring the marine environment. The joint project is being funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) with 1.5 million euros in total.