Wind blade recycling

Wind blade recycling, a new challenge for wind energy

Science Energy efficiency Offshore wind Onshore wind

The wind energy sector is experiencing tremendous growth due to the global need for clean energy supply. According to data from the World Wind Energy Association (WWEA), 840 gigawatts of wind power capacity will be installed worldwide in 2021, enough to supply more than 7% of the world's energy demand.

A clean, inexhaustible and safe energy whose best features are, moreover, that the cost of maintenance is low, that they are mobile and that they generate hardly any waste, thus helping to avoid climate change and move towards energy transition. It should be borne in mind that most of the environmental impact produced by renewable energies is concentrated in two stages: manufacture and dismantling.

This is where the importance of wind turbine recycling comes in. In Spain alone, according to data from the Spanish Wind Energy Association (AEE), there are 1,300 wind farms with around 22,000 wind turbines installed. And Spain ranks fifth in the world in terms of installed capacity, behind China, the United States, Germany and India, and ahead of the United Kingdom, Brazil and France.
 

The repowering of wind turbines

The useful life of a wind turbine is around 25 years, although it can usually be extended to 30 years if the investment in maintenance is adequate. Most of its components are recyclable, although the challenge lies in recycling the wind blades efficiently. The materials from which they are made are mostly composites, such as fibreglass, carbon fibre or various resins, so separating them for recycling is particularly difficult and expensive. 

Initially, and in keeping with the maxim of the circular economy, most of the wind turbine blades are being reused. This is part of the repowering strategy, as wind turbines are becoming increasingly more efficient and more powerful, so the old ones can be reassembled in other wind farms or in other countries. In addition, there are also initiatives that convert these blades into architectural or structural elements such as bridges or bicycle racks. However, it should be borne in mind that, according to WindEurope figures, this repowering will mean that from 2030 onwards up to 5,700 wind turbines will be dismantled in Europe per year, and given the speed at which wind energy is growing, it is necessary to opt for other alternatives as the volume of retired blades will increase rapidly.
 

Types of wind blade recycling

Although it is important to note that wind blades are inert, so they do not generate toxic emissions and their composition makes them absolutely safe for landfills, this is a significant waste of resources that moves away from the criteria of sustainability and circularity that prevail in the wind sector. Associations such as the European WindEurope are therefore calling for a Europe-wide landfill ban on wind turbine blades from 2025 onwards. This would mean that the wind industry would commit to 100 % recycling or recovery of out-of-service blades.

For this reason, different projects and initiatives are being developed to promote blade recycling through different technologies. There are currently three main types of recycling applicable to wind blade components:

 Mechanical recycling:

This involves shredding - usually after separation - the materials so that they can be reused, often as filler material, mainly in building materials or plastics. Techniques such as mechanical grinding or high-voltage pulse shredding are often used.

 Thermal recycling:

In this case, the blades are incinerated, producing energy and decomposing the composites. This process preserves certain characteristics of the fibrous materials, making them suitable for later use.

 Chemical recycling:

For chemical recycling, techniques such as fluidised bed or solvolysis are used which, by means of solvents and thermal processes, separate the resins from the fibres so that both materials can be reused. 
 

In our case, EnergyLOOP, a company promoted by Iberdrola, through its PERSEO programme, and FCC Ámbito, a subsidiary of FCC Servicios Medio Ambiente, will build its innovative wind turbine blade recycling plant in Spain. This is a pioneering facility in the recycling of wind turbine blades, mainly made up of composites (glass and carbon fibres and resins), for the recovery of these materials as secondary raw materials in different sectors such as the energy, aerospace, automotive, textile, chemical and construction industries.

In addition to promoting the development of effective and efficient techniques for blade recycling, it is also important to encourage the use of recycled composite materials, for which regulatory adaptations and business motivations are needed. And, going one step further, it is important to advance in research so that these recycled materials can in turn be used in new wind blades, thus achieving greater circularity in the industry.