Sounding out the repowering potential of wind energy – a scenario-based assessment from Germany

Abstract Wind energy in Germany is awarded a crucial role in increasing the share of renewable energies in the electricity mix to 65% until 2030, especially in light of the federal government’s recent decision to phase out coal-based electricity until 2038. In addition to the targeted expansion of wind energy, Germany will be struggling with thousands of wind turbines at the end of their service life in the next years. To advance the expansion of wind energy and to increase its efficiency, repowering is deemed a promising way to deal with the upcoming changes in wind energy use. This study assesses Germany’s repowering potential in 2021–2040. It estimates how many of the existing wind turbine sites in Germany can be used for repowering without violating recently recast geographical restrictions while at the same time meeting proper spacing criteria for repowered wind turbines. The results from fifteen scenarios indicate the repowering potential in Germany to be highly impacted by the recast geographical restrictions and wind turbine categories used to repower. Compared to the energy contributed by onshore wind in the baseline year 2021, the best-case scenario could provide 110%. In contrast, the worst-case scenario could provide 40% of potential wind energy generation in 2040. The highest potential wind energy generation is reached under low distance restrictions of 500 m to surrounding settlement areas. The results indicate repowering alone to be unable to substantially increase the share of wind energy in Germany’s energy mix over the next two decades. Without expansion, the contribution of wind energy to Germany’s energy mix will diminish. However, despite the growing number of old wind turbines in Germany, repowering still offers more efficient exploitation of the wind resource.