The End-of-Life Crisis in Wind Turbines: Can Bio-Epoxies Solve It?

Bio-epoxy is a sustainable alternative to conventional epoxy resins, made partially or entirely from renewable plant-based sources instead of petroleum-derived chemicals. These resins are developed using bio-based feedstocks such as natural oils, lignin, or other biomass-derived compounds, reducing carbon footprint and dependence on fossil fuels. Bio-epoxies retain the strong mechanical properties of traditional epoxy while offering improved recyclability, repairability, and chemical remolding potential. They are particularly researched for applications like wind turbine blades, where sustainability and end-of-life recyclability are crucial challenges.

Thermoset epoxies are extremely hard to recycle due to their strong chemical bonds, which make them durable but not reusable. Most thermoset waste ends up in landfills or is burned, which isn’t environmentally friendly. In contrast, Bio-based epoxies provide a more sustainable alternative, helping to overcome the recycling challenges of traditional thermosets while supporting a circular economy.

Bio-based epoxies in wind turbines

The wind energy sector is increasingly adopting bio-based epoxies to enhance sustainability and reduce environmental impact. Notable examples include:​ National Renewable Energy Laboratory (NREL) has recently developed a plant-based resin known as PolyEster Covalently Adaptable Network (PECAN). A 9-meter prototype wind turbine blade utilizing PECAN demonstrated promising mechanical properties and recyclability.

Several bio-based epoxy resins are available for composite applications:

1. SR GreenPoxy 56 by Sicomin: Contains 51% bio-based carbon content, offering high performance suitable for contact lamination, vacuum bagging, and hot production processes (https://sicomin.com/en/).​
2. SR GreenPoxy 33 by Sicomin: Features 35% bio-based carbon content, formulated for contact lamination, vacuum bagging, infusion, and hot production of composite structures.​
3. CeTePox® 220 R G by Aditya Birla: A modified bisphenol A/F-based liquid epoxy resin with 25-28% bio-based content, offering accelerated curing and high viscosity, suitable for fast-setting applications.​
4. Polar Bear by R*Concept: Offers a bio-based epoxy system with over 19% bio-content, specifically formulated for heat-assisted curing in compression moulding applications, such as skis and snowboard manufacturing (https://livingrconcept.com/products/).​
5. LB2 Epoxy Laminating Bio Resin by Easy Composites: With a bio-based carbon content of 31%, this resin is optimized for hand laminating processes and is compatible with various fiber reinforcements, including natural fibers like flax and jute. ​
6. IB2 Epoxy Infusion Bio Resin by Easy Composites: Designed for resin infusion applications, this resin also boasts a 31% bio-based carbon content and is particularly well-suited for use with natural fiber reinforcements. ​easycomposites.eu

European suppliers offering these bio-based epoxies include:​

• Sicomin: Headquartered in France, Sicomin specializes in high-performance bio-based epoxy resins under the GreenPoxy range.​
• Aditya Birla Advanced Materials: Offers bio-based epoxy resins like CeTePox® 220 R G and Briozen series, catering to various industrial applications.​
• R*Concept: Based in Spain, R*Concept provides the Polar Bear bio-based epoxy system, designed for heat-assisted curing in compression molding applications.​

In Europe, suppliers such as Sicomin, Easy Composites, and Resoltech offer these bio-based epoxy resins, supporting the region’s transition to more sustainable wind turbine manufacturing practices.