Wind turbines have a lifespan of around 20 years. Many parts can be reused, although this does not apply to their rotor blades. These are made of composite material that is difficult to recycle. A Danish consortium, in a joint project under the name DecomBlades, now wants to find sustainable and commercially viable solutions for recycling these wind turbine blades.
A new environmental problem has arisen with the enormous proliferation of wind turbines. Old windmills or wind turbines that are too small by today’s standards are being replaced by new, more powerful ones. Many of the old windmills can be reused. The problem is that the composite material that the rotor blades are made out of is not easy to recycle. A study by the Dutch Windesheim University of Applied Sciences estimates that this will add up to a total of 1.3 metric kilotons of discarded wind turbine blades by 2025. This figure is expected to double by 2040.
The only large-scale solutions to this problem are either through landfill or incineration. “Dumping this material amounts to passing it on to future generations,” the consortium believes. “Plus, incineration can only be done in cement kilns.”
Conventional waste incineration is not an option because of the excessively high temperatures generated in combination with harmful gases.
“Tens of thousands of wind turbines have been installed around the world over the past decades,” the Danish initiators state in a press release. “These will all have to be dismantled in the foreseeable future. The need for large-scale solutions is therefore blatantly clear.”
Incidentally, things are already happening on a small scale. The start-up Extreme Eco Solutions in the Dutch province of Gelderland, for example, makes decorative paving and wall tiles from the blades of windmills. The composite material is first ground up, a binding agent is added to it, and then it’s shaped into tiles.
John Korsgaard of LM Wind Power, one of the participating companies, explains: “The wind energy industry is committed to finding a sustainable way to recycle discarded wind turbine blades. At the moment, we don’t have any solutions yet that meet all the criteria. That’s why we want to develop them now. We want a viable, sustainable and cost-effective value chain for recycling wind turbine blades.”
The ten project partners have shortlisted three specific focus areas:
- mechanical crushing of wind turbine blades so that the material can be reused in various products and processes,
- the use of crushed material for cement production,
- a method to separate composite material under high temperatures (pyrolysis).
“Sustainable, cost-effective and widely available recycling solutions not only support the wind energy industry, but also other composite industries that are working towards achieving circular production and economy,” the consortium states.
The ultimate goal of the project is to make Denmark a leader when it comes to setting up value chains for recycling wind turbine blades that will support circular economies and create jobs both in Denmark and worldwide in the field of sustainable technologies.
The consortium comprises Ørsted, LM Wind Power, Vestas Wind Systems A/S, Siemens Gamesa Renewable Energy, FLSmidth, MAKEEN Power, HJHansen Genvindingsindustri A/S, Energy Cluster Denmark (ECD), University of Southern Denmark (SDU) and the Technical University of Denmark (DTU).