Wind Blade Research Hub: Improving the Sustainability of Wind Turbine Blades

Published 5 November 2021

By Anna Southall, Test Engineer – Blades

The wind industry has grown at an unprecedented pace, which is expected to continue over the coming decades as it delivers affordable green energy to help tackle climate change. With this exponential growth trajectory, comes the issue of sustainability. There are two parts to the sustainability challenge for wind turbine blades: what to do with the significant number of wind turbines blades about to reach the end of their design life, and how can the sustainability be improved in the huge number of new turbines currently being designed, manufactured, and installed, to minimise potential negative impacts from the growth of the sector.

ORE Catapult has many research projects that aim to improve the sustainability of blades, such as research by Dr Dimitrios Mamalis into alternative hybrid composites. Infusible thermoplastic resins for composite wind turbine blades are potentially better for recycling, in addition to enabling longer, lighter-weight, and lower-cost blades. When combining fibre metal laminates with thermoplastic resins, the impact resistance, repairability and strength can also be increased relative to conventional composites. There are also several Wind Blade Research Hub (WBRH) projects in collaboration with the University of Bristol that aim to improve testing methods for leading-edge erosion systems. One blade recycling project, led by ORE Catapult Engineer Lorna Bennet, is mapping the potential future solutions for recycling blades and a undertaking a techno-economic analysis of their suitability for large-scale deployment.

In an event hosted by the Wind Blade Research Hub, ORE Catapult, the University of Bristol and industry experts explored several key themes in the area and attempted to address some important circular economy topics.

Industry analysis and preparing to improve

Industry leaders from Siemens Gamesa Renewable Energy (SGRE) and Vestas led the way in setting the scene. SGRE showed the detailed life cycle analysis and CO₂ equivalent contributions from each component and at each stage of a turbine’s life. Examples demonstrated the complexity of considerations, but rigorous analysis showed the sector is continuously improving by increasing rotor size, extending blade lifetimes, and reducing energy consumption, as well as evaluating more disruptive changes like a recyclable resin system. Vestas shared their promising research on Circular Economy for Thermoset Composites (CETEC). Using previous research that enables the dismantling of fibres and resin, CETEC now focuses on new capability to directly recover the recycled raw materials into new epoxy resin of sufficiently high value for use in the wind industry.

Academic Research into Bio Composites

Academics from the universities of Bristol, Cambridge and Limerick all presented research into biocomposites. In this context, biomaterials are sourced from plants, and a composite is a material made from two or more distinct materials. Key benefits of biomaterials are that plants absorb carbon as they grow, and they are abundant. Starting with a reminder of how versatile natural fibres are, the speakers went on to show how biomaterials are already in use all around us and how engineers have historically used them in many applications such as windmills and cars. The presentations then covered the following three topics:

  • Performance against conventional wind turbine materials can be competitive. This encompassed fundamental research into the variation in mechanical properties from different fibre sources, comparing methods of producing fibres, and the potential to spin yarn from waste pulp.
  • A case study that compared a flax (plant-based) composite blade to a conventional glass blade demonstrated both do lead to viable designs. A benefit identified was the potential to reduce blade mass with biocomposites, but that the characteristics were different and led to different failure mechanisms, which were predicted, but showed the design should be tailored to the materials.
  • An opportunity to move away from petroleum-based materials and solvents towards carbon fibre production, by using Lignin from plants to produce the precursor fibre can also reduce life cycle metrics such as energy consumption

Technology Adoption

The National Composites Centre (NCC) presented the SusWIND programme that aims to facilitate the adoption of lower impact materials and processes by enabling a cross-sector supply chain, assessing material sustainability and supporting circular design principles.  To assess the impact of alternative blade materials, the programme establishes a baseline library of current materials and processes and develops comparison techniques so that informed decisions can speed up novel technology adoption.

Eirecomposites presented their powder epoxy resin that can lead to a reduction in material wastage. It also shared progress on its Powder blade project, which aims to design, manufacture and test a full-scale carbon and glass fibre wind turbine blade to validate the technology for thick sections. It is also developing a recyclable protective coating for wind turbine leading edges, which looks to minimise performance degradation and extend the life of the blade and is currently in operational trials showing promising results.

My Key Takeaways

Collaboration will be the key to success when it comes to wind turbines; no single sector or individual company will be able to implement the changes required to make composites more sustainable. So, events such as the one hosted by the Wind Blade Research Hub are vital to bring together and engage in order to understand each other’s perspective, capability, and limitations, and reach out to those with complementary research knowledge. The encouraging conclusion is while the challenge is big, and the scale and urgency increasing, there is already a lot of promising solutions ready to be tested by an industry which is committed to a sustainable future – could offshore wind be that industry and lead the way? It would be great to see.