Rain, hail, salt spray, airborne particles and icing are all familiar threats to a wind turbine blade's leading edge. But what about years of exposure to sunlight?
As turbines remain in service for longer, Richard Scullion, Head of Business Development at Armour Edge, believes ultraviolet (UV) resistance deserves more attention when owners assess how well blade protection will perform over its lifetime.
Looking beyond rain erosion
Modern turbine blade tip speeds can exceed 300 km/h, meaning repeated raindrop impacts can gradually damage the leading edge. This can affect aerodynamic performance and annual energy production (AEP), while repairs require technicians, access equipment and turbine downtime.
Leading-edge protection (LEP) systems are therefore commonly assessed against factors including:
Scullion argues that long-term environmental ageing should also be considered.
Unlike rain erosion, UV degradation may develop gradually and remain less visible during the early stages of a blade's operating life.
Why UV exposure matters
Prolonged UV exposure can alter the physical and chemical properties of some polymers and composite materials. Depending on the material, potential effects can include embrittlement, reduced flexibility, cracking and changes in mechanical performance.
For an LEP system, the concern is whether the material can continue performing its protective function after years of combined environmental exposure.
This becomes particularly relevant across different climates. Wind farms operate in northern Europe and the North Sea, but also in regions with intense solar radiation, including Australia, India, southern Europe and the southwestern United States.
In practice, materials may face several stresses simultaneously:
This means durability cannot necessarily be assessed by considering one environmental factor in isolation.
Material selection and independent testing
Armour Edge says UV resistance influenced its material selection from the beginning of product development.
Its shield uses a bespoke version of Luran SC, an acrylonitrile styrene acrylate-polycarbonate (ASA-PC) thermoplastic supplied by INEOS Styrolution.
According to weathering data supplied by INEOS Styrolution, the specific material used by Armour Edge retains impact toughness following extended outdoor exposure compared with several other engineering plastics.
Armour Edge also cites accelerated weathering testing conducted to ISO 16474-3. The company reports no significant reduction in measured tensile properties or hardness and no evidence of blistering, cracking or delamination. Changes were mainly limited to colour and surface gloss.
Field experience complements laboratory testing
Laboratory testing cannot reproduce every combination of environmental conditions encountered by operating turbines.
Armour Edge says its LEP system has been installed on thousands of blades across four continents, covering offshore North Sea conditions, icing in the US Midwest, dusty environments in Texas and New Mexico, monsoon conditions in India and high UV exposure in Australia.
The company also reports that its earliest offshore installations have accumulated six years of operational experience and that it has recorded no shield debonding since commercial deployment began.
A broader definition of durability
Installation quality remains another factor in lifecycle performance. Armour Edge says its system can be fitted using rope access teams, platforms or baskets, with technician training intended to support installation consistency.
For Scullion, the wider change is in how owners define durability. Resistance to rain erosion remains important, but lifecycle decisions increasingly need to consider how materials respond to several environmental stresses over decades.
As wind assets age and operating lives extend, UV resistance could therefore become a more significant factor when evaluating long-term blade protection.
Read the complete feature in PES Wind: https://pes.eu.com/exclusive-articles/beyond-rain-erosion-the-growing-role-of-uv-resistance