Spain faces the challenge of what to do with waste from wind farms that have already reached the end of their useful life. The removal of wind turbines causes a large amount of waste that, furthermore, is of very different natures.

For two years, a research group from the University of Burgos (UBU) has been studying how to revalue this waste, specifically, wind turbine blades.

This is the SUCONS (Sustainable Construction Research Group) research group. Vanesa Ortega is its director and explains that her object of research is to find a use for this waste that is already so problematic right now.

They work on converting the blades of dismantled wind turbines into materials that can be added to concrete and thus manufacture technically and economically viable concrete for use in different applications such as building or civil works. “We work on construction materials and we have decided to incorporate it into concrete,” explains Ortega. The global objective is to create resilient and sustainable environments, migrating towards a low-carbon circular economy.

Until now, Spain had not had this problem, but the first wind farms are already reaching the 25 or 30 years of useful life that a wind turbine has. Other countries have faced the dilemma of what to do with this waste before, but not all of their examples are “environmentally sustainable,” explains Ortega. «In some countries shovels are still taken to landfills or used as fuel. This is not sustainable. In other cases, for example, street furniture has been made with them,” explains the director of the research group.

The work began two years ago and they are already able to incorporate the recycled shovels into the concrete in percentages of up to 10% of this material. “This is not easy. It is not that we expect to obtain better concrete when we incorporate waste, what is expected is that you will not get better concrete than conventional concrete, but you will get concrete with adequate performance for the defined use. In this way we will be able to ensure the removal of a significant volume of wind turbine blades, by adding them to concrete, which is the most consumed construction material in the world,” adds Ortega.

The SUCONS group works with Wind Turbine Blade Grinding (TPA) obtained after a mechanical process of wind turbine blades consisting of selective cutting of the blade and grinding carried out in a blade mill.

The rest of the components of the wind mill (tower, nacelle, etc.) have their own recovery process. “The difficulty of reusing the material of the blades lies in their varied composition with polymer resins, glass fibers, polyurethane or balsa wood, among others,” says Ortega.

The incorporation of this blade crushing affects the concrete, but it does not have to be in a negative way. «In some cases we have achieved an improvement in properties because these fibers provide a stitching effect to the concrete. What we want is to obtain a material suitable for the intended application,” says the director of the research group.