Soil Characterization and Soiling Impact to Facilitate Photovoltaic Installation

There is currently an energy crisis that has led to photovoltaic operators maximizing their resources, making soiling a problem to consider in order to ensure project profitability. Energy production costs are strongly affected by the use of scarcely efficient cleaning techniques that are not suitable for a particular type of contaminant, climate, and installation. This paper introduces a technology that is suitable for studying soiling, thus decreasing the number of variables studied and reliable results were obtained. Our attention is focused on deposited material physicochemistry, local geology, and installation effects. Analysis via scanning electron microscopy and pits revealed a similarity between local geological processes and module soiling, with gypsum being responsible for soil and module cementation. Analysis with Atomic Force Microscopy confirms the cementation effect and crust formation on the lower part of the photovoltaic glass, the latter concentrating in the greatest amount of cemented material. Using a solar simulator, the characteristic curves produced by the cemented material were studied, and it was determined that the lower part of the glass produced the greatest losses (27%). Thus, a non-uniformity deposition was generated, creating resistance between the cells. From the data obtained, it was possible to make recommendations regarding making decisions about plant cleaning, instead of only considering the physicochemical analysis of the deposited material.

Automated summary

This study introduces a technology suitable for studying soiling in photovoltaic systems, reducing the number of variables studied and obtaining reliable results. The study reveals a similarity between local geological processes and module soiling, with gypsum responsible for soil and module cementation. Furthermore, it is found that the lower part of the glass produces the greatest energy losses due to non-uniform deposition causing resistance between the cells.