SPLTRAK Abstract Submission
Comparing Fluorinated and Non-Fluorinated Anti-Soiling Coatings for Solar Panel Cover Glass
Luke O. Jones1,2, Adam M. Law1, Gary Critchlow2, John M. Walls1
1Centre for Renewable Energy Systems Technology (CREST), Loughborough, United Kingdom
/2Loughborough University, Loughborough, United Kingdom

Dust, dirt, debris, and biological matter collect on the surface of solar panel cover glass and attenuate the light entering the solar cell, reducing electricity generation and power output. Hydrophobic coatings are a passive anti-soiling method that utilizes low surface energy materials to force liquid droplets to cohere together which create a ‘self-cleaning’ effect. As many hydrophobic coatings are fluorinated, this study evaluates the effectiveness of fluorine-free coatings as an alternative due to the environmental and biological risks posed by fluorine containing materials. A fluoroalkylsilane-based coating and a polydimethylsiloxane-based coating was deposited on soda-lime glass slide and exposed to 400 hours of UV and damp heat accelerated ageing tests. The two coatings were shown to be resistant to the accelerated ageing, with the fluorine-free coating marginally outperforming the fluorinated coating. For both coatings, little reduction in optical transmittance was observed, and each coating retained their hydrophobic properties in water contact angle tests. Surface chemical characterisation using X-ray photoelectron spectroscopy showed that the fluorinated coating was in the starting phase of degradation with carbonyl and methyl groups replacing trifluoromethyl groups, reducing fluorine surface content, and reducing the effectiveness as an anti-soiling coating.