Evaluation of soiling on the performance of photovoltaic systems

Abstract

The generation of electrical energy from photovoltaic plants in Brazil has been growing, and new challenges arise in this context. The deposition of dirt on the surface of photovoltaic modules is a significant cause of losses in electricity generation. The main objective of this study was to investigate, model, and analyze the impact of dirt on the energy performance of photovoltaic systems by measuring the gain obtained after cleaning two photovoltaic systems located in Rio Grande do Sul. Data from the inverter output of each system within a range of up to 30 days before and after the procedure were collected and processed. The same was done for the irradiation data obtained through the nearest INMET meteorological stations. It was possible to model the relationship between solar irradiation and energy produced using linear regression, with a determination coefficient close to 1, indicating a good model fit. A noticeable improvement in the power curve of the inverters was observed after cleaning the photovoltaic modules, especially in the case of system 1. Modest improvements were consistently observed in system 2. Additionally, in the case of system 1, the effect of the surrounding environment on the gains obtained was observed, with inverters closer to the metallurgical plant improving generation by up to 65%. The analyses also highlighted the influence of factors such as roof inclination and environmental conditions on solar energy production. However, it is important to acknowledge the limitations of this study, such as the lack of detailed data on climatic conditions and measurement accuracy. The analysis is based on data available in monitoring platforms, which may be subject to inaccuracies or technical limitations. These limitations underscore the need for future research to further explore the effects of cleaning photovoltaic modules.