On the effects of inter-farm interactions at the offshore wind farm Alpha Ventus

• Published in: Wind Energy Science 2021-11, Vol.6 (6), p.1455-1472
• Main Authors: Pettas, Vasilis, Kretschmer, Matthias, Clifton, Andrew, Po Wen Cheng
• Format: Article
• Language: English
• Subjects: Atmospheric boundary layer; Boundary layers; Offshore; Offshore operations; Turbines; Wind farms; Wind power; Wind speed
• ISSN: 2366-7443; 2366-7451
• DOI: 10.5194/wes-6-1455-2021

The energy transition means that more and more wind farms are being built in favorable offshore sites like the North Sea. The wind farms affect each other as they interact with the boundary layer flow. This phenomenon is a topic of current research by the industry and academia as it can have significant technical and financial impacts. In the present study, we use data from the Alpha Ventus wind farm site to investigate the effects of inter-farm interactions. Alpha Ventus is the first offshore German wind farm located in the North Sea with a fully equipped measurement platform, FINO1, in the near vicinity. We look at the effects on the wind conditions measured at FINO1 before and after the beginning of operation of the neighboring farms. We show how measured quantities like turbulence intensity, wind speed distributions, and wind shear are evolving from the period when the park was operating alone in the area to the period when farms were built and operate in close proximity (1.4–15 km). Moreover, we show how the wind turbine's response in terms of loads and generator and pitch activity is affected using data from a turbine that is in the vicinity of the mast. The results show the wake effects in the directions influenced by the wind farms according to their distance with increased turbulence intensity, reduced wind speeds, and increased structural loading.