Hydrophobic sol-gel based self-cleaning coating for photovoltaic panels

Abstract

Maintaining photovoltaic performance from soiling issues using manual cleaning is costly and tedious which has been a major concern in deploying this technology. Therefore, a soiling mitigation technique with self-cleaning properties such as hydrophobic coating is effective to minimize performance degradation of photovoltaic panels using sol-gel as a low-cost and scalable fabrication method. This study proposes the development and application of hydrophobic sol-gel based coating in the photovoltaic system. The aims include synthesizing a hydrophobic sol-gel based self-cleaning coating for solar panel and characterizing the hydrophobic sol-gel based self-cleaning coating. A solution is prepared using sol-gel process comprises of three different materials including vinyltriethoxysilane (VTES), tetraethoxysilane (TEOS) and tetrabutoxytitanate (TTBU) called VTT (VTES-TEOS-TTBU) sol as the organic-inorganic hybrid sol. Then, this sol is applied onto glass substrates using spin-coating method for laboratory-scale working samples. Coated samples have undergone characterizations including water contact angle measurement to obtain hydrophobic properties and surface morphology observation using microscope. The resultant VTT sol samples proven to exhibit self-cleaning ability with contact angle of 99.58° when undergo 150 °C post-bake process. The switchability of sol (hydrophilic-hydrophobic) was achieved and better transparency was observed with transmittance of 90.73% when the samples undergoing different thermal treatment during pre-bake and post-bake processes.