The effect of wakes on the fatigue damage of wind turbine components over their entire lifetime using short-term load measurements

A method is developed for quantifying the effect of neighboring wind turbines on the fatigue damage of the main components of a wind turbine over its entire operating time using short-term load measurements. This method could be used in the future for improving wind farm planning software that takes into account fatigue damage as well as energy yield or for improving lifetime extension calculations of wind turbines. The method is applied here to a measurement campaign on a Vestas V66 wind turbine located in northern Germany and the results are found to be plausible. Furthermore, the results show that the increase in total lifetime fatigue damage due to neighboring wind turbines for wind turbine separations of the order of 5D is significant and needs to be taken account of in wind farm planning software. The accuracy of the method is examined by investigating the sensitivity of the main assumptions on the results. It is found to be strongly dependent on the number of mea sured time-series in a wind speed bin as well as on the choice of wind speed frequency distribution. The method therefore needs to be standardized before it is applied to improving wind farm planning software or lifetime extension calculations of wind turbines.