Wind turbines are generally designed for a lifespan of about 20 years.
Due to the rapid technological development in recent years, it is often economically justifiable to replace one or more old, small wind turbines with new, larger wind turbines, even before the end of their technical lifespan.
In Germany, there are financial incentives for repowering such wind turbines through the Renewable Energy Sources Act (EEG). In addition to the financial benefits, repowering offers the possibility of generating more energy with fewer new wind turbines than with the previously existing wind turbines. Double the energy yield with half the number of turbines is a common rule of thumb and a fundamental goal of repowering.
Individual sites can be combined into wind farms during repowering and planning errors from the pioneering years of wind energy use (e.g., too little distance from residential development) can be corrected. However, updated requirements and laws sometimes play a decisive role in repowering.
In the meantime, an international used equipment market has developed for the old equipment that can still be used.