The baseline 6m demonstrator blade for the Carbo4Power project

In October 2024, I attended the final meeting of the Carbo4Power project in Nantes, France, at the premises of the project partner, IRT Jules Verne, who tested two 6m demonstrator blades designed by ORE Catapult.

Carbo4Power started in October 2020 and aimed to develop a new generation of lightweight, high-strength, multifunctional, digitalised multi-materials for offshore wind and tidal turbine rotor blades that will improve their operational performance, durability and maintenance intervals whilst decreasing levelised cost of energy and environmental impact. ORE Catapult is involved in several aspects of the project, including rain erosion testing, development of improved adhesives and outlining requirements for the solutions developed in the project. In addition to these tasks, we have also been responsible for investigating the benefits of manufacturing blades by assembling them from several shorter segments, and designing two segmented demonstrator blades. One of these blades has been made from baseline conventional materials, whilst the other is made from the recyclable materials developed during the project and has other Carbo4Power solutions integrated into it.

To design the blade, we started by downscaling the geometry of the IEA 15MW turbine blade (which was selected at the start of the project as the reference blade) to 1:20 scale. We then used the turbine optimisation tool ATOM (which has been developed in partnership with Bristol University as part of the Wind Blade Research Hub) to design an internal structure for the blade which would withstand the design loads. ATOM models all the relevant aspects of the turbine to calculate loads and efficiently perform structural analysis, so that the effect of tweaking hundreds of aspects of the design of the blade can be understood. This allows the design to be improved iteratively, finding the optimal trade-off between saving on material costs and generating more energy.

Once a design was completed in ATOM for both the full-scale turbine and the scaled down demonstrator, we did a cost analysis on the blade to investigate the benefits of using automated manufacturing methods and manufacturing the blade in multiple segments. This analysis showed a benefit of making the reference blade in three parts, so we next set out to understand how the joints between these sections could be designed – keeping in mind that whatever we came up with for assembling 2m sections of demonstrator blades should also work with 40m sections of the real blade!

With the joint concept defined, the final stage was to make a detailed structural model of the blade to simulate the behaviour under test – the ability to generate a solid finite element model instead of a more simple shell model was one of the key outputs of the project for the ORE Catapult.

 

Solid finite element model of Carbo4Power blade

 

A solid model represents the true structure of the blade, so all of the components are positioned in the same place as in the real blade, whereas a shell model assumes all of the material is concentrated on the outer surface of the blade. Solid models can also capture failure modes which are impossible to simulate with shell models, such as delamination (separation of the layers of the composite).

Failure plots for the Carbo4Power demonstrator blade

 

The two blades were manufactured by project partner, AIMEN, at their facilities in O Porriño, Spain. AIMEN were also responsible for procuring the mould tools necessary to manufacture the blades.

Once the blades were manufactured, the simulation model was used to define the structural test loading regime for the two demonstrator blades.

In June, I was at the testing facilities of IRT Jules Verne in Angers, France to watch some of the structural testing on the baseline demonstrator blade. The models agreed well with the physical tests and the work has been written up as a key deliverable for the end of the end of the project.

 

Comparison of displacement for the two blades and the models

 

Overall, the Carbo4Power project has been fantastic to work on – I’d like to extend my thanks to Lourdes, Rubén, Alba and the rest of the team at AIMEN for taking this blade off the computer screen and into the physical realm – I’ve designed quite a few blades now but this is the first one to make this jump! I’d also like to thank Antoine and Marie-Reine at IRT Jules Verne for all their work on making the tests a great success.