PV module monitoring system based on low-cost solutions: a Raspberry application and assessment

Resumen

During the last decade, the integration of renewables into power systems has implied multiple studies and analysis in terms of grid power quality, reliability and/or feasibility. Among the different resources to be considered as an alternative generation, wind and solar sources emerge as the most mature technologies. Indeed, they have been widely integrated in comparison with the rest of solutions and, nowadays, they account for more than 20% of generation in developed countries. With regard to PV installations, monitoring problem requires a detailed analysis, since solar radiation fluctuations, soiling on solar panels or deficiency of PV panel performance can involve unexpected output power oscillations and, subsequently, undesirable power generation decreasing. Therefore, accurate and low-cost solutions to monitor in detail PV power generation is more and more required by the sector. Under this framework, this paper describes a PV module monitoring system based on low-cost solutions, aiming to collect data at PV module level and give detailed information regarding the PV power plant performance. Actually, most current solutions are based on data collected at inverter level, and thus, monitoring solutions at PV solar module are demanded by the operators to overcome typical drawbacks related to large amount of panels to be simultaneously monitored and/or industrial rooftop solar PV plants that become difficult access. Additionally, low-cost monitoring systems are welcome as an alternative way to improve PV module performance and give predictive maintenance solutions. The proposed monitoring system is based on Raspberry systems that allow us to set personalized solutions with powerful hardware and connectivity options. Consequently, meteorological and electrical data are collected from this equipment and sent to a sink node where the information is available. Detailed information of the solution as well as preliminary results collected in a PV power plant connected to the grid are also included in the paper.