Precise calculation of wind potential facilitates financing
First commercial offshore measurement with IWES LiDAR buoy
The buoy with equipment for laser-supported remote sensing (LiDAR) passed its first real test in the shape of the winter storm “Freja” with flying colours just one week after its installation: Significant wave heights of up to 4.5 m were measured in the Danish North Sea off the coast of Thyborøn, but this did not interrupt the measuring campaign. The buoy will be in use until February 2016 for measuring wind speeds at heights of up to 250 m as part of the RUNE research project (Reducing the Uncertainty of Near-shore wind resource Estimates using onshore lidars) conducted by the Technical University of Denmark (DTU).
With deployment of the buoy and evaluation of the measuring campaign, Fraunhofer IWES, as the subcontractor, is contributing to the further improvement of yield forecasting for near-shore offshore wind farms by providing reference measurements.
“The LiDAR buoy is a key measurement reference for the experimental campaign of the RUNE project, in which we are measuring the near-shore wind from the coast with onshore scanning lidars in order to estimate the errors of mesoscale models” explained Alfredo Peña from DTU Wind Energy
Compared to fixed met masts, the buoy can be installed at any offshore location and is subject to a far less complex approval procedure. A correction algorithm developed by Fraunhofer IWES deducts the buoy’s proper motion on the waves from the measured values in order to ensure the high quality of the wind measurements. In 2014 the buoy achieved a very good correlation with respect to the validation measurements taken in the vicinity of the North Sea met mast FINO 1.
“A comparison of the wind speeds measured by the LiDAR buoy with those of the met mast FINO1 100 metres offshore proves an extremely low systematic difference between buoy and mast”, said Julia Gottschall from Fraunhofer IWES.
The LiDAR buoy can be used flexibly and offers improved planning security for project developers´ and operators´ yield calculations and design layout.