FEATURE: E&T MAGAZINE – An industry in the making: diverting wind turbine blades from landfill

Can the wind power sector be seen as green if huge amounts of plastic from defunct wind turbines end up in landfill? Turbine blades have until now not been recyclable, but that could be about to change.

Two years ago, Bloomberg published a picture of large wind turbine blade fragments being buried in earth in Wyoming, USA. ‘Wind turbine blades can’t be recycled, so they’re piling up in landfills’ the accompanying headline read. The story and image of piled-up, dusty white blades, much smaller than today’s which can reach up to 107m, was not a good look for an industry born from the need to combat climate change.

This paradox was not lost on the sector; for some time, manufacturers had been working to find solutions to a problem it knew was set to escalate. Around 25,000 tonnes of blades will reach the end of their operational life every year by 2025, this number could increase to 52,000 tonnes by 2030, according to industry trade body WindEurope.

The organisation, backed by its members, including turbine manufacturers Siemens Gamesa and Vestas, is calling for a landfill ban on wind turbine components by 2025.

“Our aim is to make them 100 per cent circular,” says Christoph Zipf, WindEurope’s press and communications manager.

At the beginning of August, the first recyclable blade, developed by Siemens Gamesa, was installed at the Kaskasi offshore wind farm in Germany, marking notable progress on this goal.

But the journey to circularity is still a long and challenging one. At present, around 95 per cent of a wind turbine – the foundation, tower and components in the nacelle, which contain materials such as steel, oil and cement – can be, and are, commonly sold into established recycling processes for profit, according to Zipf. Blades, on the other hand, are not.

They’re made of two forms of hardy plastic resins: thermosets and thermoplastics. The first forms an irreversible solid polymer that is most common and hardest to recycle, while the latter is considered simpler to remelt and recycle. Current methods available for recycling both, such as pyrolysis, which is usually conducted at or above 500°C, and mechanical recycling are considered too costly and energy intensive, however, while others are in early development phases and need to be demonstrated at scale.

Landfill, therefore, is often the only or the most cost-effective option, according to John Korsgaard, senior director of engineering excellence at LM Wind Power, a wind turbine rotor blade manufacturer. In fact, across all industries using waste fibre-reinforced plastic – used in car seats and interiors, aeroplane wings, skis, and surfboards – 60 per cent of the waste is sent to landfill.

Siemens Gamesa’s RecyclableBlade, launched in 2021, is made of a plastic resin that took five years to develop. It requires only a ‘mild’ process to break it down for recycling, according to Jakob Maennchen, team lead – casting at the company.