Navigating closed-loop recycling technologies for a circular economy of wind turbine blades

The rapid expansion of wind power installations, driven by global climate change mitigation efforts, is expected to lead to a corresponding surge in end-of-life wind turbine blades. The efficient recycling of thermoset composites (notably epoxy resin-based GFRP/CFRP) from waste wind turbine blades (WWTBs) represents a key constraint hindering the green transformation of the wind power industry. Conventional mechanical, thermal, and chemical recycling technologies face inherent limitations, including degraded fiber performance, inefficient resin recovery, and limited cost-effectiveness. Additionally, fragmented policy frameworks impede the scalability of closed-loop recycling systems. Therefore, this review systematically evaluates advancements in closed-loop recycling for wind turbine blades through three pivotal contributions: (1) By comparing the efficiency and economic feasibility of conventional methods (mechanical shredding, pyrolysis, solvent depolymerization, etc.), the fundamental shortcomings of their downcycling pathways are highlighted; (2) Through analysis of end-based and source-based recovery strategies, the potential of epoxy vitrimers in enabling synergistic regeneration of fibers and resins, as well as achieving multi-cycle recycling, are elucidated; (3) By integrating the life cycle assessment data across recycling pathways, the lack of standardized frameworks as a key barrier to industrial adoption is identified. Furthermore, this paper compares policy incentives, responsibility allocation, and legislation in the European Union, the United States, and China, proposing the establishment of a global tracking platform for decommissioned blades and a dedicated recycling economy fund. From a technology-policy synergy perspective, this review provides a systematic theoretical foundation for building sustainable closed-loop systems in the wind power industry while offering insights for advancing interdisciplinary research, novel material development, and legislative standardization.