Haoran Zhou ¹ and Andrew Park ² , ¹ USA, ² University of California, USA

Residential and small-scale solar photovoltaic systems require accessible monitoring tools to detect performance degradation and maximize energy yield, yet existing solutions rely on proprietary hardware, expensive commercial platforms, or technically complex web interfaces inaccessible to non-expert users. This paper presents a real-time IoT-based solar panel monitoring system that integrates a Flutter cross-platform mobile application with Firebase Realtime Database and an ESP32 microcontroller equipped with three INA219 current-voltage sensors for per-panel performance tracking. The system provides secure multi-user authentication, device registration with database validation, real-time streaming of voltage, current, and power metrics, and interactive multi-channel time-series visualization using the fl_chart library. Experimental evaluation demonstrated 100% data collection reliability over a seven-day monitoring period with 116 readings and sub-100-millisecond dashboard rendering performance. Open-source architecture delivers comprehensive photovoltaic monitoring at a fraction of commercial solution costs while maintaining real-time responsiveness and an intuitive mobile interface.

Solar panel monitoring, Internet of Things, Firebase Realtime Database, Flutter mobile application, INA219 current-voltage sensor