Siemens Gamesa Renewable Energy (SGRE) has produced its first six fully recyclable offshore wind turbine blades, the manufacturer has claimed.
It plans to use these blades in offshore wind farms due to be installed next year, the manufacturer told Windpower Monthly.
The new blades use a new type of resin that makes it possible to efficiently separate it from the other components at the end of the blade’s working life – previously a major obstacle to full recyclability – the firm explained.
After decommissioning, the blade will be immersed in a mild acidic solution heated with renewable energy, which will separate the resin from the fibre-glass, plastic, wood and metals.
This will allow the materials to be recycled for new purposes, including in the automotive industry or in consumer goods like flight cases and flatscreen casings.
The Spanish-German manufacturer would not reveal what resin it will now be using.
Gregorio Acero, SGRE’s head of quality, health, safety and environment, told Windpower Monthly that the development represented a “quantum leap” in making the wind power industry more sustainable.
‘Look at the ingredients’
Siemens Gamesa first began looking into the process in 2018, and evaluated the resin system in 2020 and early 2021. Earlier this year, it pledged to make all its blades fully recyclable by 2030 and its turbines fully recyclable by 2040. To meet these targets, it will now need to ramp up production of recyclable blades to an industrial scale.
It can still use the same moulds that it currently uses for its offshore wind integral blades as the dimensions of Siemens Gamesa’s offshore wind blades and most of their materials will be the same as before. This means that initial additional costs – to cover investments in research and development over the last few years, supply chain development and resin costs – will be “limited”, Martin Gerhardt, head of Siemens Gamesa’s offshore portfolio told Windpower Monthly.
He added that the company had asked itself: “How can we reuse our know-how, the quality of the blade and the integral blade design?
“The key was to look at the ingredients, and the change that was needed was the resin. That helped to deploy this fast instead of having to develop a new generation of blades.”
Siemens Gamesa has verified that the resin being used will enable complete recovery of materials following immersion in acetic acid in its own laboratories and in those of the Technical University of Denmark (DTU).
The materials recovered after 25 years of operation might not be exactly the same as before – for example, the fibre-glass might have lost some strength after a long operational life, but could still be used for low-stress applications, Gerhardt noted. He added: “It’s definitely better than burning them or putting them in landfill.”
The manufacturer recently produced the first recyclable 81-metre blades using the new resin in Aalborg, Denmark, and plans to use these blades in offshore wind projects being installed next year. It will use recyclable blades at RWE's 342MW Kaskasi wind farm in the German North Sea, and at unnamed projects being developed by Wpd and EDF Renewables.
Acero said: “We can make these blades in almost every factory because the change of technology doesn’t mean a major new investment. The recovery process is also very simple.”
Gerhardt added that new companies will need to be set up to handle recovery of the blades’ materials. However, this should be simple to do and this should create jobs in the recyling industry.
He added: “It was very important to have a process that is simple and can be done at a large scale by other companies in the supply chain, that is not harmful and doesn’t leave some residues that are problematic.”
Industrialisation
Gerhardt said the company is “very confident” in the potential to scale up the use of the new resin and acetic acid recovery process for offshore wind.There should be “no limits” to scaling up to produce recyclable blades larger than the first 81-metre models and at an industrial scale, he added.
Siemens Gamesa’s onshore wind turbine blades use a slightly different technology — with a butterfly mould instead of the integral blade design used for offshore models. Industrialisation for the different moulds will therefore proceed at a slightly different pace, Gerhardt explained.
However, the company is “very confident” that it will also be able to make its onshore blades fully recyclable, he said. It anticipates that as with the offshore blades, the key will be changing the resin used in the blades.
Competitive edge
The rollout of these blades will likely closely track market demand for more sustainable options, Acero added. He expects northern European markets to be largely aligned on this and to be among the early movers in requiring blades to be recyclable.
Acero said that company had received “keen interest” from potential customers looking to install projects with recyclable blades in 2022 and who are willing to pay more for the greener blades.
He also suggested that having recyclable blades might give Siemens Gamesa a competitive edge in markets with stricter sustainability measures in place. This could include markets such as France, which has a looming ban on landfilling blades.
“For some customers, having recyclable blades might help them to win some tenders in markets that have strict environmental requirements,” Acero said. “I think it is a winning proposition for both us as an OEM and the customer.”
Meanwhile, Gerhardt said that with growth of the wind power sector expected to accelerate, it was important to make an early start on offering recyclable blades.
“That is why we need to roll this out rather fast,” he said. The sooner we can introduce it, the more blades we can recycle.”
