Electronic measuring system design for photovoltaic panels analysis

The article presents the design and manufacture of an electronic measuring system based on an ESP32 microcontroller equipped with LORA E32 wireless data transceivers, a SD card for data recording and a computer with application for photovoltaic panels testing. Under environmental conditions the system has been experimentally tested to determine the efficiency of photovoltaic panels, which depends primarily on solar radiation and ambient parameters. In addition, the current, voltage and surface temperatures on the back side of the panels have been measured. The measuring sensors are selected in order to achieve the goal set, as well the durability of the system. The rising of the surface temperature of the photovoltaic panels have a significant effect on module’s efficiency, increasing the risk of losing energy production. In the experimental study, temperature, solar radiation, current and voltage have been measured to refine the effect on a monocrystalline and polycrystalline structure of photovoltaic panel. The test has been performed on the experimental field of the Technical University of Varna, Bulgaria. Also, the ambient meteorological parameters during the experiment are reported by a weather station mounted on the experimental field, which transmits data online in the global meteorological database Wunderground with name IVARNA50.