Evaluation of the adverse weather conditions associated to some significant European marine renewable energy projects

Abstract

The aim of the present work is to provide a general picture of the adverse weather conditions corresponding to the sites from the European coastal environment where various offshore projects are developed. In the first part of the work, the ERA5 wind and wave data (24 values per day) are processed in order to obtain the time series that cover the 10-year time interval from January 2011 to December 2020. By using some particular criteria that define the operability limit of several installation equipment (as for example the floating barges) it was possible to define several case studies. From the preliminary analysis of the wind conditions (at 10 m height above the sea level) it was noticed that the sites located in the northern regions (ocean environment) indicate higher values of the wind speeds, that can go up to 8.3 m/s compared to the value of 6 m/s indicated for the Gloria drilling platform in the Black Sea. As expected, the adverse weather patterns are directly related to the local marine conditions, being required restrictions higher than 80% in the case of the operations that are limited by the occurrences of the waves with significant wave heights higher than 1.25 m, compared to only 3.3% that define the north-western part of the Mediterranean Sea (Mistral project). The number of available windows requiring a much longer time interval (ex: 96 h) is higher in the case of Mistral and Gloria sites, being counted at least 48 opportunity events for the waves with significant wave heights below 0.5 m. Finally, it is important to mention that the analysis of the adverse weather conditions represents an important element for the marine renewable energy sector, especially as regards the enclosed basins, such as the Mediterranean or the Black seas, where offshore wind projects are expected to be implemented.