Anti-pollution Film for PV Modules installed at Railway Systems

This study focused on glass-based functional coating films to achieve anti-pollution characteristics and photovoltaic (PV) modules efficiency improvement. Anti-pollution functional coating film was applied on glass substrate made of the same material as the cover glass for PV modules. The film was applied to the PV module’s surface by spray coating method and was subsequently annealed by torching to demonstrate real field application. The number of coating application varied from 1 to 3 times to obtain different thickness of films. Natural drying of the sprayed film was done by 10 min dwelling. In sequence, firing process was performed by torch for 2 min to solidify the sprayed films. For the specimens that completed both coating and annealing processes, characteristics including anti-pollution ability, contact angle, and light transmittance were analyzed. Contact angle was analyzed using a contact-angle analyzer, while light transmittance was analyzed using UV–visible capable of utilizing the integrating sphere. Based on the characteristics analyzed, the manufacturing process of the functional coating film was optimized. If the coating process proposed in this study is applied to PV modules, improvement in anti-pollution characteristics as well as efficiency can be expected.