Wind energy has become a key player in global electricity generation. The management of end-of-life (EoL) wind turbine blade (WTB) material streams is a challenge that requires urgent attention. The aim of this study was to forecast the future EoL WTB material, composition and geographical distribution of decommissioned on- and offshore wind turbines in Germany. Based on the German core energy market data register and a review of forecasting methods, a hybrid approach was developed that combines a statistical, deterministic and stochastic model with three scenarios to assume the service life of wind turbines in operation. This method was applied to Germany to estimate the mass of WTBs until 2050. The results show that a total EoL WTB material mass of 698 kt is expected, consisting of 492 kt of glass fibre reinforced polymer WTBs and 206 kt of hybrid WTB material with a carbon fibre reinforced polymer mass share of approximately 12.4 kt. From 2024 onwards, a displacement of 64.4 km in the centre of gravity of the expected EoL WTB material stream towards the north-west coast of Germany could be observed. The authors demonstrate the novelty of the method and findings in relation to circular economy paths of EoL WTB material.