The KNMI North Sea Wind (KNW) Atlas provides wind climatology for the North Sea and the Netherlands.
The climatology has an accuracy better than 0.3 m/s at wind turbine heights onshore and 0.2 m/s at wind turbine heights offshore, which is comparable to measurement accuracy. The atlas data (time series and fields) can be downloaded for free from the KNW-website (http://projects.knmi.nl/knw/). The website also provides a user manual and all relevant scientific documentation and information tailored to the needs of the wind energy sector.
The atlas is based on the 35 year (1979-2013) ERA-Interim global re-analysis. A global re-analysis is a 3D summary of all relevant measurements in the world (5 million every 12 hours) which is both the best possible fit of these measurements and consistent with the laws of physics. KNMI’s operational weather forecast model HARMONIE has been used to downscale the global re-analysis from 6 hourly to hourly and from 80 to 2.5 km grid-spacing. With 225 quadrillion calculations 35 years of high-resolution wind information was produced up to 200m height. The downscaled re-analysis was then tuned to match high-quality wind speed measurements from the Cabauw mast (http://www.cesar-observatory.nl/) by applying a wind shear correction of 15% uniformly throughout the whole dataset. The shear-corrected data have been validated against wind mast and satellite measurements.
KNMI intends to: