DOWA deliverables

Within the DOWA project

• KNMI will extend the KNMI North Sea Wind (KNW) atlas (1979-2013) until at least March 2019. Both day and time series files can be downloaded for free via the KNMI Data Platform (KDP).
• ECN part of TNO assessed high altitude winds (up to 1.5km) at the ECN part of TNO Petten research location with its recently purchased  scanning LiDAR. This was done for November and December 2017. A comparison of these LiDAR wind measurements with KNW data generated by KNMI (up to 600 m in elevation) can be found in publications on this website.
• ECN part of TNO assessed the offshore wind conditions at the North Sea in terms of profiles (results can be found in publications) and low level jets (results can be found in publications) using various measurement platforms comprising meteorological masts and both floating and platform-mounted LiDARs.
• KNMI produced a 10-year (2008-2017) wind climatology called the Dutch Offshore Wind Atlas (DOWA), which is a valuable addition to the KNW atlas. All information on the DOWA can be found on the project page). The DOWA was validated by ECN part of TNO and KNMI against satellite wind measurements, wind measurements at the Cesar Observatory (i.e. the Cabauw tower), and against both offshore metmasts and offshore and coastal profiling LiDAR measurements. DOWA-data are publicly available. There is also a user manual to explain how the data can be readily downloaded.
• Whiffle improved the modelling  of the wind turbine wake effects (wind shadows) of individual turbines and wind farms using Whiffle’s LES-model GRASP. Results were compared to measurements from the ECN wind turbine test site EWTW. KNMI worked on the parametrization of wind farm wake effects in their mesoscale weather model HARMONIE-AROME, using Whiffles GRASP-simulations and WRF-simulations for comparison. Results of these studies can be found in publications.
• Whiffle produced a wind climatology for the Dutch wind farm zones Borssele, Hollandse Kust Zuid and Hollandse Kust Noord that include wake effects of the neighboring wind farms. Results and validation reports using floating LiDAR measurements can be found in publications.
• KNMI and Whiffle developed methods to nest LES-models (DALES/GRASP) with and without wind turbines in the mesoscale weather model HARMONIE. Results can be found in publications.
• ECN part of TNO modelled the effect of the North Sea offshore wind conditions on wind turbine performance and loads in AeroModule using Whiffle’s GRASP output for normal and extreme conditions. Results can be found in publications.
• Recommendations for improved wind resource assessments resulting from uncertainty assessments of wind climatology are drafted by ECN part of TNO and KNMI. The results can be found in publications.