ANALYSIS OF WIND-SPEED OBSERVATIONS ON THE NORTH-SEA COAST

As part of the objective to describe the wind climate of the North Sea and the coastal zone, specifically with regard to wind energy applica tions, we study the observations of two meteorological stations on the North Sea coast: Hoek van Holland (HVH) and IJmuiden (IJM). Statistic al analysis of the 8-year datasets shows that the mean wind speeds are 7.8 m/s (at 18.5 m height) for IJM, and 7.6 m/s (at 15.0 m height) fo r HVH, respectively. The coastal observations are compared to the obse rvations of three offshore platforms in the North Sea analysed in earl ier work. It is found that diurnal variations are very similar in autu mn and winter, but differ in spring and summer. Furthermore, wind spee ds with fetch over sea do behave very similar at the coastal stations and offshore platforms. It is shown that the effects of thermal circul ation leading to the sea breeze are distinctly present, at least up to 30 km offshore. These effects can be attributed to relatively low win d speeds (less than 7 m/s at 10 m height), and manifest themselves as a shift, on average, of wind directions from easterly to westerly dire ctions during the day. Higher wind speeds (more than 7 m/s), most rele vant for wind energy applications, compare well at coastal stations an d offshore platforms. (C) 1998 Elsevier Science B.V. All rights reserv ed.