Characterizing the coverage of anti-soiling coatings on photovoltaic modules

Photovoltaic modules can provide an economical and accessible source of renewable energy. However, due to the accumulation of dust, also known as soiling, solar panels are susceptible to significant energy loss, especially in regions with harsh climatic conditions, like India and the Middle East.

Hydrophobic anti-soiling coatings can be used to mitigate this dust, though they may respond adversely to environmental stressors. Bhaduri et al. demonstrated tapping mode atomic force microscopy (TM-AFM) phase imaging as a method for analyzing the loss in coverage of a surface coating material due to various environmental stressors.

The authors monitored four different commercial coatings sprayed onto solar glass samples under different weather conditions, including exposure to rain over a 40-day period in which 7 inches of precipitation was recorded, and an acid test.

They found the non-coated control sample exhibited about triple the adhesive force on their surface compared to the coated samples, which means dust and other debris are much more likely to stick to the non-coated surface. They made this observation through the phase-contrast in phase images between the coated and uncoated areas. This significant difference in phase angle is observable through TM-AFM phase imaging and provides evidence that the technique can be used to quantify a coating’s surface coverage.

According to the group, an ideal hydrophobic anti-soiling coating needs to have a lifetime of about 25 years. To optimize the longevity and reliability of these coatings, the effects of additional environmental stressors need to be understood, such as snow and ultraviolet radiation. TM-AFM phase imaging can be a useful tool for these studies.

Source: “Characterization of reliability of anti-soiling coatings using Tapping Mode – AFM Phase Imaging,” by Sonali Bhaduri, Sudhanshu Mallick, Narendra Shiradkar, and Anil Kottantharayil, Journal of Renewable and Sustainable Energy (2021). The article can be accessed at https://doi.org/10.1063/5.0039255 .

This paper is part of the State-of-the-Art Research on Quantifying and Mitigating Soiling and Abrasion for Solar Power special collection, learn more here .