Soiling: The Science and Solutions

Many elements determine the optimum output of a PV module, one of which is the concept of soiling. Soiling occurs as a result of dirt, dust and other particles covering the surface of the PV modules. Dust composition widely varies across the globe, which affects both the type and amount of soiling. There are a number of methods to quantify and monitor soiling. These include conventional pairing of PV reference cells, as well as smarter methods, such as advanced data analysis. It is imperative to measure soiling for operational PV plants as well as pre-construction site surveys, since soiling can anticipate future performance. To eliminate the effects of soiling, panels require cleaning, which can be carried out utilizing either wet or dry solutions. The cleaning methods fall into the three main categories of manual, mechanised-manual and robotic cleaning (subdivided into automated or semi-automated). Although soiling cannot be prevented, its negative effects can be mitigated by means of deploying dust-repellent agents and coatings.