Severe leading-edge erosion presents wind farm operators with a difficult maintenance decision. Once damage progresses through the coating and filler into the structural laminate, repair becomes slower, more weather-sensitive and harder to execute consistently.
New work combining UV-curable materials, fibre reinforcement and robotic process control could provide another option between conventional structural intervention and blade replacement. Aerones is developing this approach, although the company acknowledges that Category 4 and 5 robotic repairs are not yet proven as a commercial standard.
Why severe erosion is different
Up to Category 3, the repair process is relatively established: prepare the damaged surface, restore the blade profile with filler, apply leading-edge protection and return the turbine to service.
Category 4 and 5 damage is more complicated because erosion has typically reached the laminate. Operators must consider:
Aerones has modelled this progression using a 3 MW reference turbine in a high-rainfall environment. Its model estimates that damage could increase from 7.3 m per blade in year four to 9.1 m in year five, with repair costs rising from around $16,200 to $32,400 and annual energy production losses increasing from approximately 258 MWh to 390 MWh.
These figures are company-supplied and should be regarded as illustrative rather than independent market benchmarks.
Reducing cure time with UV materials
One of the biggest practical constraints in severe blade repair is cure time. Conventional two-component epoxies and polyurethanes can require hours before the next stage can begin, with temperature and humidity influencing the process.
For a robotic system suspended on a blade, this waiting time reduces the available weather window.
Aerones is therefore working with a materials manufacturer on a UV-curable leading-edge protection system. The material would be applied and checked before being cured on demand using an onboard UV source.
This could allow faster layer build-up and more predictable repair times, but the technical requirements are demanding. The material must spray consistently, adhere correctly, cure to the required depth and retain erosion resistance.
Aerones reports promising early rain erosion testing, but third-party comparative data and field results will be needed to assess long-term durability.
Adding structural function
Faster curing alone does not address the structural challenge of Category 4 and 5 damage.
Aerones is also developing a repair matrix containing milled glass fibres. The intention is to improve mechanical performance and strengthen the bond between the repair material and underlying laminate.
The main technical considerations include:
Testing is taking place at Aerones’ Riga materials laboratory using full-size blade stands. This allows the company to assess whether the material can be applied consistently to realistic blade geometry rather than relying solely on coupon testing.
Integrating the complete repair process
The main opportunity lies in combining the technologies. A robotic system capable of preparing the surface, applying reinforced material, checking thickness, curing layers on demand and recording the process could make severe erosion repairs more repeatable.
Automated process control could support vision-based surface recognition, spray-path control, layer-thickness verification, cure confirmation and defect detection. It could also produce a digital quality assurance record.
These functions would support rather than replace engineering judgement.
Aerones’ robotic equipment is designed to work directly on turbine blades, illustrating the type of suspended field environment in which these processes would ultimately need to perform reliably.
If severe erosion can be repaired more predictably, operators may have more options before committing to blade replacement. That could influence maintenance reserves, campaign planning and life-extension decisions.
The technology is not there yet. Robotic repair for Category 4 and 5 damage still needs repeatable field validation and replacement will remain appropriate for some blades. However, the direction is clear: severe erosion repair is moving towards more controlled, materials-led robotic processes.
For the full Industrial Insight feature on UV-curable materials, fibre-reinforced systems and robotic repair for severe leading-edge erosion from Aerones, visit: https://pes.eu.com/exclusive-articles/can-robotic-repair-change-the-economics-of-severe-leading-edge-erosion