Progress in resource utilization of waste wind turbine blades

The large-scale utilization of wind energy is the key to establishing a modern energy system, an essential prerequisite for achieving carbon peaking and neutrality as planned, and an essential support for quality economic and social development. The installed wind power capacity continues to grow in China; by the end of 2022, the number of installed wind turbines had surpassed more than 170000 sets, and that of the cumulative installed blades had surpassed 3.65 million tons. Accordingly, early wind turbines are being decommissioned. The use of end-of-life wind turbine blades as a resource presents numerous challenges, such as disassembly- and degradation-related issues. Therefore, there is an urgent need to investigate green and high-value utilization technology paths capable of large-scale consumption to support the green and sustainable development of the wind power industry. This review examines the wind power industry and the growth trend of end-of-life wind turbines in China, outlines the main technical pathways of waste wind blade resource utilization, and highlights several waste wind blade resource utilization methods. ① Mechanical, thermal, and chemical recycling methods for fiber-reinforced composites: Mechanical recycling is a simple and traditional pathway that cannot provide long-scale fibers, thermal recycling damages the mechanical properties of long-scale fibers and makes reusing the matrix resin difficult, and chemical recycling preserves the mechanical properties of long-scale fibers and allows for the reuse of the matrix resin but at a high cost. Therefore, to achieve the sustainable reuse of reinforcing fibers and matrix resin, further research on the low-cost recycling method for fiber-reinforced composites from waste wind turbine blades is required. ② Application of waste blades in concrete and other construction materials: The blade, when cut into small pieces, can be used to replace natural aggregates in concrete materials. However, its organic components are not conducive to cement hydration, nor are the low-strength filler materials, such as balsa wood, conducive to the structural strength of concrete. ③ Structural utilization of waste blades: Waste blades can have structural reuse applications in pedestrian bridges, park benches, playground facilities, bus stops, and house roofs. Although reuse is simple and feasible, the blade materials need to be rendered nonhazardous and resourceful after the reuse cycle. This review compares and analyzes the benefits and drawbacks of various technical solutions to provide a reference for future research on the utilization of waste wind turbine blades.