Developing recyclable wind turbine blades using a closed loop

The industrial challenges of the ZEBRA project

Wind energy contributes to the energy transition, but the management of blades at the end of their life remains a major challenge. The ZEBRA project seeks to treat production and end-of-life waste while maintaining the performance expected for large blades.

• design blades using materials compatible with full recycling;
• recover resin and glass fibres separately for reuse;
• organize a closed loop covering manufacturing, dismantling, shredding, and recycling.
• assess life-cycle environmental benefits;
• demonstrate the economic viability of the recycling system.

The consortium covers the entire value chain, from blade materials and manufacturing to waste treatment and life cycle analysis.

Technologies developed for blade recycling

ZEBRA combines several complementary materials and processes to enable closed-loop recycling of thermoplastic blades:

• use of the thermoplastic resin Elium® and development of an Elium® monomer recycled by thermolysis;
• development by Bostik of an adhesive dedicated to blade assembly, recyclable with Elium® resin;
• use of Ultrablade® high-performance glass fabrics;
• cutting and grinding of blades at the end of their life;
• optimisation of the recycling of production and end-of-life waste, in particular by mechanical recycling;
• recovery, remelting and reintegration of glass fibers into the Sustaina® range;
• realization by ENGIE Lab CRIGEN of a life cycle assessment according to ISO standards, covering more than ten environmental indicators.

The thermolysis process achieved an efficiency of more than 75% for the recovery of the Elium® monomer.

Project results and industrial impacts

The ZEBRA project demonstrated the technical feasibility of a recyclable thermoplastic blade and a closed-loop recycling system.

• manufacture of two 1-scale blades, 62 metres and 77 metres;
• manufacture of a blade with a major structural element made from recycled Elium® resin;
• successful recycling of Elium® resin, Bostik adhesive and Ultrablade® fabrics;
• recovery of glass fibers and reintegration into new products;
• Up to 30% reduction in CO₂ emissions per blade through closed-loop recycling, compared to a non-recycled ZEBRA blade.
• validation of the results of the life cycle assessment by a panel of four independent experts;
• confirmation of the environmental benefits and economic viability of the closed-loop system.

These results show that a circular approach can reduce the environmental impact of blade production and limit the use of virgin resources.