Wind energy experts: the circular economy is coming to this area too

Recycling the blades of the wind turbines that are powering renewable energy in the country has for many years been used by opponents of wind energy as an argument that these power plants are not sustainable. Meanwhile, wind energy experts reassure us that the latest technologies allow not only to resurrect used blades, but also to produce new blades that are easier to recycle.

Wind blades are mainly made from a mixture of glass or carbon fibre composites and plastic or other materials. This combination of raw materials ensures the durability and longevity of the blades, which can last up to 25 years under normal operating conditions.

“The lifetime of the blades in a wind farm is essentially the same as the lifetime of the wind farm – 20-25 years. During this period, the wind turbines that are produced are usually significantly improved. Nowadays, the newest plants are much taller and more powerful than their predecessors built 10-15 years ago, so wind farm developers inevitably tend to scrap the old ones and build more modern ones in their place,” commented Edgaras Maladauskas from the Lithuanian Wind Energy Association (LVEA).

He says that although Lithuanian developers are currently only approaching the end of the life of the first wind farms – the first wind farm in the country was built 20 years ago, and the first larger wind farm 17 years ago – there is no need to worry about the possibility of recycling old wind farm blades.

From wind to cement

Both wind farm manufacturers and park developers are constantly looking for ways to recycle wind turbine blades. In the US, Veolia North America, a waste, water and energy management company, has started to use wind blades to make cement in 2020: the dismantled and shredded blades are burned in cement kilns, where they not only replace part of the coal used, but also become part of the cement produced. According to the company, this process converts around 65% of the wind turbine blade components into cement raw material and 28% into a fuel alternative.

Recycling of wind turbine blades has also been tried in Lithuania. Last year, a group of researchers from Kaunas University of Technology (KTU) and the Lithuanian Energy Institute (LEI) carried out several experiments to break down glass-fibre-reinforced plastics into their constituent parts – aromatic compounds and fibres. According to the researchers, the aromatic compounds could be used for resin production, while the chemically cleaned fibre residues could be used for a variety of applications, such as concrete, polymer composites or fibre coatings.

“Although wind turbine blades are non-toxic and therefore safe to dispose of in landfills, most manufacturers and developers realise that such disposal is a waste of valuable resources – recycled blades can be re-purposed into a new form and product and used in other industrial sectors or for other purposes,” said Maladauskas.

He recalls that Wind Europe, the European wind energy industry’s umbrella organisation, published a position paper in 2021 calling for a ban on the disposal of wind turbine blades by landfilling in Europe from 2025. Austria, Finland, Germany and the Netherlands have already legislated for such a solution.

“The aim is for wind blades to be 100% recycled, recovered or reused. The first wind turbine manufacturers probably did not foresee this possibility, so recycling used blades seemed like an insurmountable challenge for some time. However, as technology continues to advance, new opportunities are now opening up for both recycling and reusing blades. This is the right way to go – recycle, reuse, reuse, I am glad that wind energy is in it, and that the goal of this field is to use the resource as sustainably as possible,” said the LVEA representative.

The circular economy will take off

One of the most successful recycling options for wind farm blades is to adapt them to make new blades. Danish energy company Vestas Wind Systems launched a solution earlier this year that allows new blades to be made from used blades without changing their composition or design. The revolutionary technology is expected to transform all epoxy composite materials into a source of raw materials for the wider circular economy – not only for wind energy, but also for other industries facing product recycling challenges.

A similar technology was presented last year by Kazem Fayazbakhsh, an associate professor at Ryerson University in Canada, who and his team of researchers have discovered a way to turn used wind turbine blades into a polymer that could be used as a 3D printing feedstock for ultra-rugged products. According to the researchers, polymer-reinforced parts are in high demand in a wide range of industries, not just wind farms.

While the recycling of wind turbine blades is gaining ground in the market, there is no shortage of more creative solutions: in Ireland, blades have been used to build a pedestrian bridge, in the Netherlands for a playground, and a Danish company used them to build a bicycle shelter.

“It is likely that all wind turbine blades will be recycled in the near future, especially as much more advanced solutions are now being applied to the manufacture of new turbines, making it easier to bring their blades back to life,” emphasises Maladauskas.

Siemens Gamesa, one of the leaders in renewable energy, has introduced the RecyclableBlade in 2021, a recyclable wind turbine blade that uses a new type of resin that is more easily separated during recycling, which allows for the successful reuse of all raw materials. Other companies are following suit.

“Until now, the blades have been the biggest challenge when it comes to wind turbine recycling, because most of the components of a wind turbine – cement, electronics, wires or metal parts – are already recycled. However, if we compare wind turbines with other forms of electricity generation, such as nuclear power, they take much longer to dismantle and pose much greater challenges for both the environment and society. In this respect, wind power remains the most environmentally and socially friendly way of generating electricity, even after the plant has reached the end of its useful life,” he said.