Antireflective, photocatalytic, and superhydrophilic coating prepared by facile sparking process for photovoltaic panels

Soiling of photovoltaic modules and the reflection of incident light from the solar panel glass reduces the efficiency and performance of solar panels; therefore, the glass should be improved to have antifouling properties. In this work, commercial solar panels were coated with sparked titanium films, and the antireflective, super-hydrophilic, and photocatalytic properties of the films were investigated. The reflectance, photocatalytic properties, and degradation of the organic pollutant methylene blue were determined using UV–Vis spectroscopy. The wetting properties were studied by measuring the water contact angle using an optical tensiometer. The outdoor power of the spark-discharged-titanium coated and uncoated PV panels was measured for 10 months at Chiang Mai, Thailand. It was found that conditions such as cloudiness, rainfall, and muddy stains significantly influenced the power difference (ΔP) between the coated and uncoated PV panels. The increase in ΔP was due to the improved dust removal from the super-hydrophilic surface of the coated panels. On a cloudy day, ΔP reached its highest value of 14.22%, which was anticipated to improve the anti-reflection property of the coated glass. The average ΔP was 6.62% over the entire experimental period.