Comparison of weather data from FINO3 and ERA5 in Wind Farm Installation Campaign Simulations.

Abstract

Weather data are commonly used in the planning phase of an offshore wind farm installation campaign. Knowledge of site-specific weather conditions is of great importance regarding transport and installation as well as potential performance of the wind farm. When observational data are not accessible for the location of interest, the data can be obtained from a forecast based on models and observations. In this study a comparison is made between observational weather data from the FINO3 research facility and weather data from the global ERA5 climate reanalysis at matching location for the period 1.10.2013-30.09.2019. The data from both sources was collected, filtered and matched with respect to time. A comparison was done between wind speed at 100-meter altitude as well as the wave height, also addressing the uncertainties associated with the ERA5 reanalysis. A simulation was conducted using the intelligent simulation tool SIMSTALL from Shoreline to address the project installation time and accumulated waiting on weather for a hypothetical wind farm using weather data input from FINO3 and ERA5. It was found that though the wind speed data from the ERA5 reanalysis on average was slightly higher than observations from FINO3, the number of available wind weather windows for the installation processes was higher in the ERA5 dataset. For the wave height data, the ERA5 reanalysis showed a small underestimation compared to observational data. This led to a higher number of wave weather windows in the ERA5 dataset. For the total installation time of the fictive wind farm created, the use of ERA5 weather data led to a month earlier completion as an average of twelve different starting months compared to using the observational data from FINO3, with a completion time of 534 days using ERA5 weather data and 564 days using FINO3 weather data.