The challenge: indestructible wind turbine blades

What began as an experimental search for a way to process decommissioned wind turbine blades has evolved into a proven method now being applied in new infrastructure projects. This marks a crucial step toward solving a global waste problem that is becoming increasingly urgent as wind farms continue to expand. After ten years of intensive research, a breakthrough has been achieved: the circular solution developed by the Polymer Technology research group at Windesheim University of Applied Sciences is now being applied on an industrial scale.

Wind turbine blades are made of exceptionally strong materials: composites. These materials are designed to last for decades. However, many wind turbines have now been in operation for just that long, and an increasing number of rotor blades require replacement. Replacement generates large volumes of waste. These so-called “end-of-life composites” were virtually impossible to process. With the rapid expansion of wind farms, especially offshore, the problem has grown exponentially. An urgent circular solution was needed to prevent this material stream from becoming a new environmental burden.

Harnessing the strength of the material

The Polymer Technology research group at Windesheim University of Applied Sciences developed a method for reusing composites without compromising their exceptional material properties. In this process, discarded composite material is reduced to robust flakes, which are then used as reinforcement in new composite products. By embedding these flakes in fresh resin, a fully functional and durable material is produced. In this way, the old composite becomes the new composite, without any loss of quality.

The research and further development of this method are led by Dr. Ir. Albert ten Busschen, principal investigator at the Polymer Technology research group. Together with a network of more than 80 partners from industry, government, and knowledge institutions, his team developed the technology into a scalable and robust solution.

The breakthrough: from innovation to industry

The technology is now being used to manufacture new products on an industrial scale. At CRC, discarded composite products are processed in large volumes into new raw materials. Compone then uses these materials to produce new composite products. These products can be applied, for example, to infrastructure projects. With this, the innovation has officially transitioned from a research project to the market.

The move toward industrial-scale application was not taken lightly. To demonstrate that the technology works, the materials were extensively tested over a period of ten years for strength, stiffness, moisture behavior, and fatigue. Under a wide range of extreme conditions, performance remained intact. The results show that the recycled composite delivers the same performance as the virgin material.

In addition, an independent research institute (SGS Intron) confirmed that no harmful substances leach from the material. This means the recycled composite is safe for both people and the environment. Life-cycle analyses further show that this method yields significant environmental benefits, partly due to the long lifespans of the new products.

Concrete applications

As part of the research, the technology has been applied in real-world projects, including:

• Shore protection structures consisting of 80 recycled sheet piles
• Guide barriers that safely lead ships into the harbor
• A dragline mat for heavy construction traffic
• Deck planks on a traffic bridge in Friesland, subjected daily to thousands of vehicles

These applications demonstrate that recycled composite not only works in theory but also proves its value in practice.

Internationally, the method is now recognized as a realistic and scalable solution to the growing problem of composite waste in the wind energy industry. Windesheim actively participates in international working groups focused on building a circular future for the sector.