Analyzing the Effectiveness of Various Coatings in Mitigating Soiling and Enhancing Reflection for Photovoltaic (PV) Systems in Desert Climate

In desert climates, the performance of Photovoltaic (PV) systems may benefit, on one side, from high solar irradiation and high albedo; however, on the other side, the performance of the PV system may suffer from the accumulation of dust on the PV module front glass. In this work, two different anti-soiling coatings (ASC) and anti-reflection coatings (ARC) coupons were developed and tested in real operating conditions and compared with uncoated glass coupons. UV-vis-NIR, light microscopy, and SEM analysis were carried out. Soiling was measured in terms of loss in light transmission and increase in surface area coverage. Uncoated glass leads to a higher loss in light transmission and a higher surface coverage area compared with ASC and ASC/ARC. ASC coupons show higher hydrophilicity and, therefore, less soiling. Across 8 weeks of outdoor exposure and 3 cleaning cycles, analysis of 3728 light microscopy images revealed a mean dust surface coverage area for ASC, ASC/ARC, and uncoated coupons of 17.9%, 15.3%, and 20.0%, respectively. For the cycle between November 14 and November 26, the ASC, ASC/ARC, and uncoated coupon dust surface coverage areas increased by 32.2%, 27.2%, and 22.0%, respectively. Unlike the ASC/ARC and uncoated coupon, the ASC recovers to its initial condition right after coupon cleaning. Degradation of the ASC/ARC coupons and uncoated glass was systematically observed.