Gone with the wind? Wind farm-induced wakes and regulatory gaps

Abstract

Wind farm-induced wakes can propagate dozens of kilometres, decreasing the power production and the fatigue lifetime of wind turbines between neighbouring farms. This phenomenon termed hereinafter “wind theft”, may lead to legal conflicts between wind farm operators and even States as power production from a wind farm is affected by the wake effects generated by another, reducing power output. Wind theft can substantially slow down the development of offshore wind if it is not regulated by a clear legal framework. In this study, we present the case of Sørlige Nordsjø II, a large offshore area that opened for wind turbine licensing application in 2020, is explored. This area is located in the Norwegian exclusive economic zone (EEZ) on the border to the Danish equivalent zone. Using state-of-the-art reanalysis data covering 1992–2020, it is shown that long farm-induced wake will likely propagate regularly from SN2 into the Danish EEZ and vice versa. This research shows how the United Nations Law of the Sea Convention 1982 leaves a regulatory gap regarding cross-border wind wake effects. As Europe crucially needs to expand its renewable energy production and work towards its net zero objectives by 2050, coastal States should cooperate to find regulatory solutions to wake effects such that wind resource management can be optimised. While some North Sea coastal States demonstrate a political will to cooperate, such policies must proliferate into legal instruments which lend certainty and predictability to wind resource management.