Investigating the wind conditions in the North Sea for wind turbines at sites N-3.5, N-3.6 and N-7.2

Abstract

<p>The Offshore Wind Energy Act (Windenergie-auf-See-Gesetz - WindSeeG) legally requires annual tender procedures for sites in the North Sea in the Exclusive Economic Zone of Germany for the construction of wind turbines. The Federal Maritime and Hydrographic Agency (Bundesamt für Seeschifffahrt und Hydrographie - BSH) conducts so called preliminary investigation of sites (PIS), pursuant to §10 WindSeeG. These include investigations of the wind conditions at the site, to give the interested firms information for calculating a bid. The preliminary investigation of the wind conditions is conducted together with the German Weather Service (Deutscher Wetterdienst) and is based on three elements: a measurement campaign at the site for one year, an evaluation of reanalysis data by the German Weather Service, and a report which brings together all available information about the wind conditions. These reports are published together with the measurement and model data and the results of all other preliminary investigations via the PIS-Data Hub https://pinta.bsh.de as part of the tendering process.</p><p>The sites that are dedicated for the construction of wind turbines are defined in the Site Development Plan (Flächenentwicklungsplan), together with the year of the intended tendering process. The first PIS have been successfully completed for two sites in the southeastern North Sea and for one site in the Baltic Sea in March 2021. In the years 2022 and 2023, a call for tender for sites N-3.5, N-3.6 and N-7.2 will be published. These sites are located in the southwestern part of the German Exclusive Economic Zone in the North Sea. At or near these sites, meteorological measurements have been conducted, using a floating lidar which was installed on a buoy (site N-7.2) as well as scanning lidars installed on the transition pieces of wind turbines (N-3.5, N-3.6). These measurements resulted in time series of vertical profiles of wind direction and speed, covering one year each, and giving information about the wind conditions at the sites at relevant heights of future wind turbines. In addition, temperature, relative humidity, air pressure, and sea surface temperature were measured.</p>