Wind farm wake effects at the Alpha Ventus offshore wind farm

As wind energy grows to a significant contributor to the electricity production mix, the number of wind farms with large turbines, especially offshore, increases as well. This leads to wind farms being built closer to each other to increase spatial power density. The close proximity of these farm arrays has been shown to create wake effects that have impacts on the power production and the loading of the downstream farms. The research community and industry have shown a lot of interest in recent years to understand, quantify, and model these phenomena as they have both financial and technical impacts. In this work, we present measurement data from the Alpha Ventus wind farm site. Alpha Ventus is the first German offshore wind farm operating at the North Sea since 2010. A large amount of data has been gathered since, with the RAVE research consortium managing research activities there. Alpha Ventus consists of 12 5MW turbines. Moreover, just in front of the wind farm there is a large, fully equipped meteorological mast, FINO1, gathering data since the preconstruction period. Since 2015 more wind farms have been constructed and commissioned close to AV (in distances from 1.5 to 10 km) with similar size turbines but much larger in terms of total capacity. This setup gives us the unique opportunity to investigate the effects, over the years, on the local wind conditions and the turbine response as the surroundings changed from free stream conditions to operating wind farms. In this work, we present measurement data from FINO1 and the AV turbine in the direct vicinity for the period 2011-2019. The goal is to quantify the effects of the wakes of the new farms that started operating at different points in time and different distances from AV as well as to provide a comprehensive overview of the metocean conditions at the site over the years