Soiling measurement station to evaluate anti-soiling properties of PV module coatings

Soiling can be a significant loss factor for PV systems, accounting for >5% annual energy loss in locations without frequent rainfall. Therefore, many manufacturers are investigating the potential benefits of incorporating anti-soiling or self-cleaning properties into PV module coatings. In order to study the potential anti-soiling behavior of various surface treatments, we have deployed a test station with custom-made PV modules having coatings with both hydrophilic and hydrophobic properties that may inhibit soiling and/or induce self-cleaning. The soiling of each sample is determined by comparison to an automatically washed reference cell in the station. We present the motivations for and design of the station, along with preliminary results regarding the impact of the coatings on soiling.