Hub Height Ocean Winds over the North Sea Observed by the NORSEWInD Lidar Array: Measuring Techniques, Quality Control and Data Management

In the North Sea, an array of wind profiling wind lidars were deployed mainly on offshore platforms. The purpose was to observe free stream winds at hub height. Eight lidars were validated prior to offshore deployment with observations from cup anemometers at 60, 80, 100 and 116 m on an onshore met mast situated in flat terrain. The so-called “NORSEWInD standard” for comparing lidar and mast wind data includes the criteria that the slope of the linear regression should lie within 0.98 and 1.01 and the linear correlation coefficient higher than 0.98 for the wind speed range 4–16 m∙s−1. Five lidars performed excellently, two slightly failed the first criterion and one failed both. The lidars were operated offshore from six months to more than two years and observed in total 107 months of 10-min mean wind profile observations. Four lidars were re-evaluated post deployment with excellent results. The flow distortion around platforms was examined using wind tunnel experiments and computational fluid dynamics and it was found that at 100 m height wind observations by the lidars were not significantly influenced by flow distortion. Observations of the vertical wind profile shear exponent at hub height are presented.

[1]  C. Draxl,et al.  Evaluating winds and vertical wind shear from Weather Research and Forecasting model forecasts using seven planetary boundary layer schemes , 2014 .

[2]  Charlotte Bay Hasager,et al.  Wind Class Sampling of Satellite SAR Imagery for Offshore Wind Resource Mapping , 2010 .

[3]  Jakob Mann,et al.  LiDAR error estimation with WAsP engineering , 2008 .

[4]  Thomas Scanlon,et al.  Computational and Experimental Study on the effect of flow field distortion on the accuracy of the measurements made by anemometers on the Fino3 Meteorological mast , 2011 .

[5]  Alfredo Peña,et al.  SAR-Based Wind Resource Statistics in the Baltic Sea , 2011, Remote. Sens..

[6]  C. M. Sonnenschein,et al.  Signal-to-Noise Relationships for Coaxial Systems that Heterodyne Backscatter from the Atmosphere. , 1971, Applied optics.

[7]  H. Jørgensen,et al.  Wind lidar evaluation at the Danish wind test site in Høvsøre , 2006 .

[8]  F. Menter,et al.  Ten Years of Industrial Experience with the SST Turbulence Model , 2003 .

[9]  Michael Harris,et al.  Introduction to continuous-wave Doppler lidar , 2012 .

[10]  Thomas Scanlon,et al.  Measurement and simulation of the flow field around a triangular lattice meteorological mast , 2012 .

[11]  S. Bradley,et al.  Corrections for Wind-Speed Errors from Sodar and Lidar in Complex Terrain , 2012, Boundary-Layer Meteorology.

[12]  Ole Rathmann,et al.  Getting Started with WAsP 9 , 2003 .

[13]  Charlotte Bay Hasager,et al.  Offshore vertical wind shear: Final report on NORSEWInD’s work task 3.1 , 2012 .

[14]  Charlotte Bay Hasager,et al.  Spatial and temporal variability of winds in the Northern European Seas , 2013 .

[15]  S. Gryning,et al.  Offshore wind profiling using light detection and ranging measurements , 2009 .

[16]  Charlotte Bay Hasager,et al.  Effectiveness of WRF wind direction for retrieving coastal sea surface wind from synthetic aperture radar , 2013 .

[17]  Steven Lang,et al.  LIDAR and SODAR Measurements of Wind Speed and Direction in Upland Terrain for Wind Energy Purposes , 2011, Remote. Sens..

[18]  N. M. Zoumakis.  The dependence of the power-law exponent on surface roughness and stability in a neutrally and stably stratified surface boundary layer , 2009 .

[19]  Per Jonas Petter Lindelöw,et al.  Testing and comparison of lidars for profile and turbulence measurements in wind energy , 2008 .

[20]  J. Mann,et al.  Conically scanning lidar error in complex terrain , 2009 .

[21]  Stefan Emeis.  Wind energy meteorology : atmopsheric physics for wind power generation , 2013 .

[22]  Andrew Oldroyd,et al.  An eight month test campaign of the Qinetiq ZephIR system: Preliminary results , 2007 .

[23]  Ioannis Antoniou,et al.  The influence of the wind speed profile on wind turbine performance measurements , 2009 .

[24]  Charlotte Bay Hasager,et al.  The NORSEWInD numerical wind atlas for the South Baltic , 2012 .

[25]  J. van Beeck,et al.  Turbulent fluxes, stability and shear in the offshore environment: Mesoscale modelling and field observations at FINO1 , 2012 .

[26]  S. Larsen,et al.  Remote Sensing for Wind Energy , 2013 .

[27]  Charlotte Bay Hasager,et al.  SST diurnal variability in the North Sea and the Baltic Sea , 2012 .

[28]  Siegfried Raasch,et al.  Getting a better understanding of the offshore marine boundary layer: Comparison between Large Eddy Simulation and offshore measurement data with focus on wind energy application , 2010 .

[29]  K. Moffett,et al.  Remote Sens , 2015 .

[30]  Yasuyuki Baba,et al.  Estimation of Offshore Wind Resources in Coastal Waters off Shirahama Using ENVISAT ASAR Images , 2013, Remote. Sens..

[31]  hya sree.M,et al.  Lidar Remote Sensing , 2015 .

[32]  Charlotte Bay Hasager,et al.  NORSEWIND – Mesoscale model derived Wind Atlases for the Irish Sea, the North Sea and the Baltic Sea , 2013 .

[33]  Charlotte Bay Hasager,et al.  Wind characteristics in the North and Baltic Seas from the QuikSCAT satellite , 2014 .