Recycling of wind turbine blades

Wind turbine blade recycling
As the design of win turbines aims levels of 6 MW per turbine, more material is needed. Besides, owners of the first generation of wind turbines merely look for replacement of their present turbine by a bigger one. With a booming wind energy industry, the question is now arising of how to deal with ex-service turbines, and particularly the blades made of hard-to-recycle composites.

Wind turbine blades typically consist of reinforcement fibers, such as glass fibers or carbon fibers; a plastic polymer, such as polyester or epoxy; sandwich core materials such as polyvinyl chloride (PVC), PET or balsa wood; and bonded joints, coating (polyurethane), and lightning conductors.

Years ago, KEMA, Aerpac and Hanze Milieu together conducted an inventory study of possible processing methods for the discarded blades as the blades of the wind turbines of the wind park Eemshaven were in need of replacement. The blades, which had to be removed due to technical defects, have been replaced by new higher-quality blades.

KEMA conducted the project REACT, where recycling possibilities have been tested. Various thermal processing methods and material recycling options were considered. Two processing methods turn out to offer the best prospects. In the short term, thermal processing of the turbine blades in the cement industry will be possible. In the longer term, mechanical recycling is to be preferred. Within this project research was done on:
- a new hybrid grinding technology
- recyclate reactivation for optimal mechanical properties
- separation of different materials in the waste fraction
- new applications for FRP recyclate.

Read more in the feature of the Reinforced Plastics issue of January/February 2009, written by Kari Larsen and published by Elsevier or download more public project information.