Wind blade design for disassembly

The wind energy industry is currently the most prominent renewable energy sector in the UK, accounting for 24% of its total energy production in 2020. In order to increase the feasibility and sustainability of this vital technology, significant steps need to be taken to reduce the material waste generated by wind turbine blades at end of life.
Primarily, blades are manufactured from glass or carbon fibre epoxy composites. While this enables them to withstand the extreme weather and cyclic loads they are exposed to, recycling or repurposing these materials upon the blade's decommission is a currently unsolved problem. The most common practice is simply to bury the blades in a landfill, thus completely disregarding the possibility of potential reuse and recirculation of these high value composites. Alternative measures such as burning or mechanical grinding are becoming more popular. However burning the blades for fuel is far from ideal due to the low energy content of the materials and the hazardous pollutants emitted when burning glass fibre. While mechanical grinding of the blades for use in the construction industry is more environmentally conscious, with the amount of energy used to manufacture and process the blades initially, is this really the best we can do in terms of reuse?
In order to maximise the material value of the blades at end of life, the most efficient reuse strategies would aim to repurpose whole, as-manufactured composite components. This would allow for minimal loss of mechanical performance as well as maximal energy efficiency in terms of manufacturing and processing replacement parts. To implement such a strategy in the wind energy industry, a "Design for Disassembly" philosophy needs to be implemented at the point of initial blade design.
This project aims to embody this design philosophy by conceiving a new blade design focusing entirely on disassembly. In this work, 'disassembly' is defined by two main criteria; modularity and structural separation of internal blade components. A blade design combining both these aims will allow for the most efficient reuse of blade materials while preserving as much of their intrinsic value as possible. To achieve this, research into the most effective joining mechanisms in terms of load-transfer and ease of disassembly will be conducted. A thorough investigation into the manufacturability and cost of the proposed designs will be completed, by which structural performance and industrial practicality can be correctly balanced. Accurate turbine simulation modelling will also be undertaken to ensure the dynamic performance of the redesigned blade is sufficient for operation, and can be verifiably considered as a promising next stage of wind turbine blade design.

There are seven principal groups of beneficiaries for our new EPSRC Centre for Doctoral Training in Composites Science, Engineering, and Manufacturing.

1. Collaborating companies and organisations, who will gain privileged access to the unique concentration of research training and skills available within the CDT, through active participation in doctoral research projects. In the Centre we will explore innovative ideas, in conjunction with industrial partners, international partners, and other associated groups (CLF, Catapults). Showcase events, such as our annual conference, will offer opportunities to a much broader spectrum of potentially collaborating companies and other organisations. The supporting companies will benefit from cross-sector learning opportunities and

- specific innovations within their sponsored project that make a significant impact on the company;
- increased collaboration with academia;
- the development of blue-skies and long-term research at a lowered risk.

2. Early-stage investors, who will gain access to commercial opportunities that have been validated through proof-of-concept, through our NCC-led technology pull-through programme.

3. Academics within Bristol, across a diverse range of disciplines, and at other universities associated with Bristol through the Manufacturing Hub, will benefit from collaborative research and exploitation opportunities in our CDT. International visits made possible by the Centre will undoubtedly lead to a wider spectrum of research training and exploitation collaborations.

4. Research students will establish their reputations as part of the CDT. Training and experiences within the Centre will increase their awareness of wider and contextually important issues, such as IP identification, commercialisation opportunities, and engagement with the public.

5. Students at the partner universities (SFI - Limerick) and other institutions, who will benefit from the collaborative training environment through the technologically relevant feedback from commercial stakeholder organisations.

6. The University of Bristol will enhance their international profile in composites. In addition to the immediate gains such as high quality academic publications and conference presentations during the course of the Centre, the University gains from the collaboration with industry that will continue long after the participants graduate. This is shown by the

a) Follow-on research activities in related areas.
b) Willingness of past graduates to:

i) Act as advocates for the CDT through our alumni association;
ii) Participate in the Advisory Board of our proposed CDT;
iii) Act as mentors to current doctoral students.

7. Citizens of the UK. We have identified key fields in composites science, engineering and manufacturing technology which are of current strategic importance to the country and will demonstrate the route by which these fields will impact our lives. Our current CDTs have shown considerable impact on industry (e.g. Rolls Royce). Our proposed centre will continue to give this benefit. We have built activities into the CDT programme to develop wider competences of the students in:

a) Communication - presentations, videos, journal paper, workshops;
b) Exploitation - business plans and exploitation routes for research;
c) Public Understanding - science ambassador, schools events, website.