Recycling and recovery of wind turbine components. A global techno-economic state-of-the-art and future prospects

Synthesis

Disclaimer: The content of this publication is based on the state of knowledge and the regulatory framework in force at the time of publication of the documents.

Study context

While the first onshore wind farms installed in France are reaching the end of their life and a massive increase in dismantling operations is expected from 2025, causing significant flows of materials, the question of management and becoming of dismantled wind turbines arises: reuse, recycling and recovery of components and materials are among the options — apart from elimination, the least desirable solution.

Even so certain materials from wind turbines are recyclable and recoverable in existing French sectors, several challenges remain, particularly with regard to the recycling of blades, based on composite materials, and the recycling of permanent magnets containing rare earths. A number of developments are underway concerning the dismantling, recycling and eco-design of these different components and materials.

Objectives and study plan

In this context and with regard to these issues, RECORD has initiated a study relating to the recycling and recovery of wind turbine components, aiming to establish a state of the technico-economic art and the associated perspectives.

Firstly (step 1), the study draws up a state of the technical and economic art of the wind turbine end-of-life sector on the French, European and global scales. This state-of-the-art addresses different dimensions: deposits and future of wind turbines, legislative and regulatory frames, value chain of the sector, operational and technical aspects around dismantling and sorting operations, transport and post-dismantling logistics, technologies and blade recycling and recovery processes already operational, economic viability.

Secondly (step 2), and specifically for blades and permanent magnets, the study examines possible developments with regard to recycling processes and technologies on the one hand and, on the other hand, the implementation using innovative and eco-designed materials. For blades, new processes, not yet mature, are described, as well as new materials, potentially presenting greater recyclability. For permanent magnets, processes are also described (mostly not mature), as well as work still at the research stage on the opportunity to replace rare earths or reduce their content.

A final step (step 3) presents a conclusive summary presenting the main lessons of the study gathered in a SWOT matrix. In a logic of sector structuring, it is proposed that these diagnostic elements serve as input data for future work, aimed at defining possible strategic orientations accompanied by levers and avenues of action.

Results and discussion

State of the technico-economic art

The analysis carried out in France reveals a deposit of wind turbines at the end of their life increasing from 2025, reaching almost 1 Mt of materials around 2030 then oscillating between 0.5 and 1 Mt during the following decade. In other regions in Europe (Germany, Netherlands, Denmark, etc.) and around the world (United States), operations to dismantle wind farms – mainly land-based – have started for several years already. French deposits of composite material waste from onshore wind turbines at the end of their life are well mapped, with volumes capable of supplying a recycling sector from 2025. Conversely, French deposits of permanent magnets based on rare earths appear limited for 20 years, because only 5% of French onshore wind turbines are equipped with them and the dismantling of marine wind turbines will not take place before 2040.

Concerning the future of decommissioned wind turbines, there is a European or even extra-European market for reuse (second-hand machines, spare parts) and reuse (new uses of blades) making it possible to delay and postpone the recycling and recovery stages, avoiding as much as possible elimination by incineration without energy recovery and/or landfill disposal. But these markets are not able to absorb all the wind turbines at the end of their life, so that large-scale recycling and recovery appear inevitable.

Legislation and regulations relating to the end of life of wind turbines are marked by an evolution towards a structuring framework for the dismantling and recycling of end-of-use wind turbines. The European Union's waste policy is high-level and regulatory requirements specific to wind power are set at national, regional and even local levels (dismantling of machines and foundations, waste management, site restoration). To compensate for the lack of an international industrial standard governing the decommissioning and dismantling of onshore wind turbines and contribute to the development of such a standard, WindEurope (Task Force for Dismantling and Decommissioning launched with the aim of harmonizing national standards which apply to the decommissioning and dismantling of wind turbines) presented an industry guidance document for the decommissioning of onshore wind turbines in 2020 and submitted this guidance to the International Electrotechnical Commission (IEC — Technical Committee TC 88 for wind energy generation systems) with a view to contributing to the amendment of technical specification 61400-28 CD relating to the end of life of wind turbines.

In France, the technical requirements applicable to dismantling activities for wind turbines at the end of their life are governed by the (amended) decree of August 26, 2011 and dismantling and restoration operations are provided for in article R515-106 of the Environmental Code. On the other hand, if in France (Environmental Code, Agec law) as in Europe (European framework directive 2008/98/EC relating to waste), the management of most waste is the subject of legislation and of precise regulations (waste of concrete, metals, electrical cables, used oils), there are few regulatory requirements for composite waste in France as in Europe (variable classification of composite waste leading to a diversification of waste streams to the detriment of a single stream), just as there is (yet) no specific European or national legislation relating to rare earths — in the latter case the situation is evolving because the European Commission presented in March 2023 its strategy to secure supply chains for critical and strategic raw materials CRMA (Critical Raw Materials Act) and on March 18, 2024 the Council of the European Union gave its approval to the regulation on critical raw materials.

In France, industrial players of all sizes are present in most links in the value chain of the wind turbine end-of-life sector (dismantling, sorting, transport and post-dismantling logistics, reuse, recycling and recovery). But companies in this ecosystem must face strong foreign competition, particularly in Europe where sectors for dismantling and recycling end-of-life wind turbines are already well established in countries active in onshore wind power (Netherlands, Denmark, Germany, Spain) but also for installed offshore wind power (Germany, Belgium, Denmark, Norway, Netherlands, United Kingdom).

For composite material blades, recycling and recovery technologies and processes are already operational — mechanical recycling, chemical recycling by pyrolysis or solvolysis, energy/material recovery as solid recovery fuels, incineration. The two most commonly used technologies (the most mature and economically affordable/viable) are fine mechanical grinding (material recovery but poor quality of recyclates and limited outlets) and incineration in cement plants or coprocessing (material and energy recovery as solid recovered fuels but lost glass fibers and competition with other sectors using composites). But these methods will only make it possible to absorb the outgoing flows from wind farms during the transitional phase where these flows are still limited (volumes, temporality, synergies with other sectors), prior to the structuring and industrialization of a sector of recycling strictly speaking and according to an adapted economic model. Hence a certain uncertainty about the industrial capacities for recycling and recovery of blades. Permanent magnets based on rare earths can be directly reused after reconditioning the magnets, but with the limitation indicated above concerning the deposits.

Another point of vigilance concerns the economic viability of the wind turbine end-of-life sector. In 2023, in view of the volumes processed, the value created and the variations in the prices of materials, the operational profitability of the activity of recycling wind turbines at the end of their life is low, even negative - difference between the cost of operations dismantling (costs of the dismantling site e.g. equipment, labor, pre-treatment on site, costs of disposal of various materials e.g. composites, concrete) and recycling on the one hand and, on the other hand, the product that the recycler can obtain from it (amount invoiced to the park operator, sale of entire machines, sale of spare parts, sale of ferrous and non-ferrous metals, sale of concrete aggregates, sale of various materials, for example fiberglass or carbon, rare earths, SRF). In the particular case of blades and permanent magnets, respectively, composite materials from wind turbines at the end of their life will be mainly based on glass fibers until 2035-2040, reinforcements based on carbon fibers (higher value) having only been used from 2015; as for magnets, less than 1% of all used permanent magnets are today recycled according to this 2022 study.

Last, a final point of vigilance concerns the environmental and health impacts of the end of life of wind turbines, in particular with regard to the blades. In the outdoor environment, feedback from experts such as an Internet review indicates that there is little or no consideration of dust emission problems (grinding, saw cutting, plier cutting) or smoke releases (torch cutting) during the handling and processing of the blades, nor noise protection measures.

Expected developments for blades and permanent magnets

For blades, in addition to solutions already industrialized or in the process of being industrialized (see above), innovative recycling and recovery processes and technologies are the subject of exploratory work, in particular gasification by fluidized bed, microwaves-assisted pyrolysis, high voltage fragmentation based on the use of pulsed electric currents, plasma pyrolysis, vapopyrolysis/vapothermolysis, as well as high or low temperature and pressure solvolysis. These alternative solutions, applied alone or in combination, present different levels of technological maturity (industrialization), vary in their effects on the quality of the fibers (glass or carbon) at the end of the process — which influences or determines the way in which the recyclates can be reused. The orientation towards a given recycling technology depends on the nature of the different constituents of the material (matrix, reinforcements) or the intended application for the use of the recyclate.

For blades also, other breakthroughs are expected concerning the use of innovative and eco-designed materials, potentially with greater recyclability: Elium thermoplastic resin and ZEBRA project, RecyclableBlade, vitrimers, self-reinforced polymers, etc. With leading players (IRT Jules Verne, Arkema, Canoe, Engie, Suez), France is present on the ZEBRA (Zero wastE Blade ReseArch) project. However, France is almost absent from major European R&D programs (Horizon 2020, Horizon Europe) relating to blade recycling and recovery technologies and processes. To watch carefully: projects that aim to develop solutions applicable to blades currently in service and to other industries using thermosetting composites — CETEC (chemolysis), DecomBlades (pyrolysis).

For permanent magnets, the outlook mainly concerns short-loop recycling (regeneration of the magnetic alloy) and long-loop recycling (chemical extraction of rare earths), as well as the possibility of reducing the rare-earth content. These different pathways are still at an early stage. France has expertise with the CEA-Liten, a few companies and the MAGNOLIA project (MAGNets on pilOt LIne Ambition — project which aims to structure in France an industrial sector for recycling and manufacturing sintered permanent magnets), mainly on the short loop, also on the long loop but to a lesser extent. France is also present in some major European R&D programs (Horizon 2020, etc.).

Conclusions

The great diversity of shapes (structures) and compositions (chemistries) of blades made of composite materials and magnets based on rare earths is currently an obstacle to efficient and widespread recycling of these components. The heterogeneity of the deposits reflects the diversity of constructors/manufacturers/equipment suppliers leading to the absence of standardization (design/conception) and traceability of components.

In this context, in addition to the foreseeable or expected advances in the processing of blades and permanent magnets, regulations play a major role in encouraging turbine manufacturers to improve the circularity of the sector by rationalizing and optimizing operations (dismantling, sorting/transport/logistics, recycling technologies and processes) and, beyond that, promoting inter-industry convergences (repositories with different origins and uses — composites, magnets). Because for the moment, the treatment of waste from all sources - massification of deposits - is not possible (necessary separation of flows of materials/waste to be recycled).