Design of an Ultra-Low Powered Data-Logger for Stand-Alone PV Energy Systems

This paper presents an open-source, ultra-low powered data-logger for off-grid photovoltaic (PV) energy systems. Deep-sleep mode of ESP32-S2 microcontroller is used along with voltage, current, and light sensors for logging the data of PV energy system to an external micro SD card. A toggle switch is used to switch the operational modes of data-logger between deep-sleep and web-server modes. Real-time PV data can be monitored in a local web-portal programmed in the microcontroller. The same web-portal is also used to check and download the historical data of a PV energy system. The energy consumption of the designed system is 7.33mWh during deep-sleep mode and 425mWh during the web-server mode. The total cost of the designed data-logger is C$ 30