Wind energy has now emerged as a leading form of renewable energy as we transition from a reliance on fossil fuels. This is very much the case in Ireland, where the total installed wind capacity is approximately 4.6 Gigawatts. A major milestone for the industry took place in February 2022 when 53% of Ireland’s electricity was produced by wind, which is wind energy’s highest-ever share for a single calendar month. The Irish Government has committed to growing the wind energy sector in the Climate Action Plan 2021, which includes a target of 5 Gigawatts of offshore wind by 2030, resulting in the proportion of renewable electricity produced in Ireland reaching 80% by 2030.
However, although wind energy is commercially viable, with widespread installations around the globe, further innovations and technology development is required to ensure wind energy’s sustainable development. In response to this, the Sustainable & Resilient Structures Research Group at the National University of Ireland Galway (NUI Galway) is undertaking a number of research projects for the development of technologies for improving sustainability and resilience of wind turbine blades, which is being led by Dr William Finnegan and Professor Jamie Goggins. The Sustainable & Resilient Structures Research Group is part of the SFI MaREI Research Centre for Energy, Climate and Marine and have developed a world-leading Large Structures Testing Laboratory in the Alice Perry Engineering Building at NUI Galway. The research work being performed by the Research Group for improved sustainability and resilience of wind turbine blades is broadly broken down into the following three categories:
- Leading edge erosion
- End-of-life strategies for wind turbine blades
- Offshore wind technology development
This research is funded through the SEAI National Energy Research Development and Demonstration (RD&D) Funding Programme, by SFI through the MaREI Research Centre and the European Commission.
Leading edge erosion
Wind turbine blades operate in harsh environments, encountering strong UV rays, sand laden winds, rainwater, salt spray, humidity and temperature fluctuations. As a result, a major cause of damage to wind turbine blades is erosion by repeated impacts of water droplets. Damage initiation can be caused by multiple factors, including sand particle impact and hail. Such damage results in a loss of energy generation due to changes to the aerodynamic profile of the critically-important blade leading edge. Therefore, in order to protection the leading edge of wind turbine blades, protective systems have been developed but, as blades get longer and tip speeds increase, these protective systems begin to fail as early as in the first 5 years of operation.
The SEAI-funded BladeLEP project, which was led by the University of Limerick and NUI Galway were a partner, used a range of tests to explore and rank the performance of 9 leading edge protection systems; these tests included whirling arm rain erosion testing, tensile testing and dynamic mechanical thermal analysis testing.
One of the systems explored was previously developed in the EASME-funded LEAPWind Project, which was led by the ÉireComposites and NUI Galway were a partner. This system, which is still under development, was a thermoplastic polyurethane based protection system that is bonded to the leading edge of the wind turbine blade.
The next phase of the research is to take the highest ranked leading edge protection systems and investigate them further, while also exploring the effect of biofouling and contamination of wind turbine blades. This research will be conducted in the SEAI-funded SPOTBlade project, which was led by the University of Limerick and NUI Galway, IT Carlow and TU Dublin are partners. This project will employ two rain erosion testing approaches to study the mechanisms responsible for damage initiation and erosion propagation, along with exploring coating systems for preventing biofouling and contamination.
Dr William Finnegan is also contributing to policy development, along with colleagues in University of Limerick and IT Carlow, as part of the IEA Wind Task 46 on Erosion of Wind Turbine Blades.
End-of-life strategies for wind turbine blades
It is estimated that up to 17% of wind turbines in Ireland will reach their end-of-life by 2030, which represents approximately 700 Megawatts of installed capacity. The current disposal strategy for wind turbine blades is landfill, which is highly unsustainable. Therefore, innovative solutions for end-of-life strategies for wind turbine blades are needed.
To support the development of efficient and effective end-of-life strategies for wind turbine blades, researchers from NUI Galway, University College Dublin, University College Cork, Trinity College Dublin, Munster Technological University and Gavin and Doherty Geo-solutions, have come together to undertake the SEAI-funded WindLEDeRR project. Within this project a range of tools will be developed for decision-making tool at end-of-life, holistic structural dynamic modelling, structural health monitoring, damage detection and predicting remaining fatigue life and residual strength. In addition, solutions for sustainable decommissioning of wind turbines and the repurposing decommissioned blades in Ireland will be developed.
An alternative approach is to extend the useful life of the turbines through strategies like re-blading. The SEAI-funded REBLADE project, which is led by ÉireComposites and NUI Galway are a partner, aims to develop advanced technologies to retrofit aging turbines through re-blading with new highly efficient and resilient blades. It will, hence, extend the working life of the turbines, while increasing their efficiency and power production. To achieve this, the project will design, manufacture, and mechanically test the new wind blades, which are suitable for installation in Irish wind farms to extend the life of the turbine.
Offshore wind technology development
The Irish Government have set an ambitious target of installing 5 Gigawatts of offshore wind by 2030. Researchers in NUI Galway are supporting Marine Materials Ireland to develop their novel offshore wind energy technology through the SEAI-funded DeepWindDemo project. MMI are proposing a disruptive and innovative solution for the Irish floating wind industry, by bringing to the floating wind sector a novel dual helical turbine on a single platform, which not only maximises the use of materials, but also has performance benefits with the bypass velocity of one turbine used to increase the intake velocity of the other. The team at NUI Galway will de-risk the new turbine blades through advanced structural testing prior to operational trials.
The research work described in this article is expected to directly lead to more sustainable and resilient wind turbine blades. By working with leading Irish renewables supply chain stakeholders, such as ÉireComposites and Marine Materials Ireland, the technologies developed will be implemented in industry to increase the competiveness of the wind energy sector. To ensure project results and technologies reach wider than the project consortiums to all key stakeholders, significant dissemination activities, including presentations at trade shows and international conferences, peer-reviewed scientific publications and hosting of information workshops for industry, have been planned across a number of wind energy projects.
The technologies developed in these projects will explore solutions for the prevention of leading edge erosion in both onshore and offshore wind turbine blades, strategies for blades at their end-of-life and novel solutions for harnessing of offshore wind energy. For wind energy developers, this will see the operational costs of wind energy installations reduce, resulting in a lowering in the levelised cost of wind energy to a point where it is economically, not just environmentally, a better option than generating energy from fossil fuels.