An assessment of the metocean conditions in the Belgian offshore zone

This paper investigates the performance of two wind speed databases (NORA3 and ERA5) for wind resource assessment in an offshore wind farm located in the Belgian Exclusive Economic Zone. A combination of data from ERA5 and NORA3, SCADA and LiDAR measurements, and data from an in-situ anemometer on an offshore pile is used. The study assesses wind speeds at a typical hub height in different spatial location and temporal coverage. Since NORA3 has been developed for the Norwegian coast, this analysis also assesses how this model performs in different sites of the Belgian offshore zone. This study shows that NORA3 and ERA5 leads to a positive bias, indicating an overestimation of wind resource and, consequently, the power production estimation, due to the local depletion of wind resources caused by neighbouring wind farms. Nevertheless, both wind models have a good agreement with in-situ measurements, as indicated by the high coefficient of determination (R2).