Parallel session 4: End of life and renewable energies – the example of wind turbines.

In this session we welcomed a stellar panel: Mr. Ferdinand Zotz, Head of Resource Management and Circular Economy, Ramboll Group from Munich, Germany; Mr. Martin Westbomke, Chairman of the Board, RDRWind, Germany; Mr. Jinfeng Zhang from the Blade Certification Division of the National Energy Key Laboratory for Wind and Solar Simulation, Testing and Certification, China; and Ms. Marylise Schmid, Analyst – Environment & Planning, Wind Europe, Belgium. The session dealt with what happens to wind turbines at the end of their life and how they can be sustainably decommissioned, dismantled and recycled.

Mr. Westbomke‘s presentation presented the project that was carried -together with the DIN, the German Normalisation Institute- to create an industry standard for such a sustainable process of decommissioning, dismantling and recycling of turbines (the DIN SPEC 4866). He also stressed the most vital steps to be taken next for this process to be fully implemented and integrated in a sustainable wind energy system: establishing networks with different stakeholders, supporting innovation and new technologies wherever possible and extending the scope of such a process to offshore wind turbines, which is currently non existent.

A central topic of the debate was the significant growth of wind turbines installations since it is considered to be one of the renewable energy techniques that has the best environmental performance with the lowest green gas emission and a standard life cycle of turbines of around 20 to 25 years. Nevertheless, as Ms. Schmid pointed out, some might reach up to 35 years and around 85 to 90% can be recycled, and it has been proved that most of the components had established cycling practices.

The wind turbines’ blades are considered the most challenging for recycling, because of the composite materials leading in their production. Ms. Schmid related this to a key point of the session: collaboration between different sectors and actors is needed to move forward, in this case towards a sustainable way to recycle composite materials. Apart from this, energy producers are responsible for the lifetime extension of turbines, via the inspection of the damage and the evaluation of continuous maintenance, and searching for innovative techniques for the blades’ recycling. As a last point to consider, it is important to find out the appropriate locations in which to put the blade waste recycling facilities (only a few countries have made landfill ban for composite materials i.e. Austria, Germany Netherlands, and Finland).

Mr. Zhang‘s presentation presented the current common practices in blade recycling in China, including various types such as physical, chemical or thermal recycling. He explained the current technologies used in physical recycling, and how the materials can be processed and given a new life in several ways (e.g. it is possible to obtain PVC for sealing, or to used the crushed retired turbines for cement or power plants).

A point that was stressed several times was the need for further research and fundings in order to be able to diversify technologies for recycling waste materials into new products, or otherwise, creating new materials that can be easily recycled.

Reported by: Hana Ben Mahrez (Eötvös Loránd University, Budapest, Hungary) & David Amado-Blanco González (Lund University, Sweden).