the ordinate correspondingly x and y are the x coordinate or respectively the y coordinate of the wind turbine for which it is to be determined whether this wind turbine is disrupted by other wind turbines dx is the distance along the abscissa between the wind turbine to be determined and the neighboring and operating wind turbine and correspondingly dy is the distance along the ordinate in this regard u03b2 is the angle between the wind turbine to be determined and the neighboring wind turbine compared to the north direction u03b3 uf603 u03b2 u03c5 dir uf604 u03b1 2 it can be determined whether the respective wind turbine belongs to the disrupted wind turbines this is the case if u03b3 has a negative value here u03b3 is the disruption indication angle and v dir is the wind direction these calculation steps are performed for all wind turbines that are in operation only the wind turbines that always have a positive u03b3 belong to the first group of wind turbines namely the wind turbines with freely inflowing wind all others belong to the second group of wind turbines for which the wind is not freely inflowing in order to now determine the energy yield deficit of a wind turbine at standstill or respectively operated in a reduced energy yield mode the respective group division is performed for example in a 10 minute average value of a wind direction and the yield deficit of the nonoperational wind turbine or respectively the wind turbine which.