Real-Time Monitoring and Diagnostic of Rooftop Monofacial PV System Validated with Thermography

Photovoltaics reliability was based on the availability of performance monitoring systems and identifying the causes of deterioration, if any, to ensure the system’s efficiency and reliability. The electrical operating conditions have a direct impact on the thermal performance of the module which is rarely considered. Several thermal models and implemented in the simulation software, however, the estimated module temperature’s precision for different electrical operating conditions is not defined, which the current work is focused on. A real-time monitoring application has been developed to assess the thermal behavior of three sets of rooftop PV systems performance, at Jean University campus in Spain, operating at different electrical statuses; a short-circuited PV set-1, open-circuited PV set-2, and PV set-3 operate at the maximum power point (MPP). The monitoring revealed that the module temperature of the short-circuited PV system is 8.5% more than the one of the open-circuited PV system. Moreover, the module temperature of the MPP operating PV system is 20.73% and 10.39% less compared to the short-circuited and open-circuited one. The NOCT thermal model overestimates the module temperature the PV system operates at MPP by 15.33% while the Faiman model overestimates it by 16.65%.