Design of an Energy-Optimized IoT System for Off-Grid Agriculture: Solar-Powered Monitoring and Irrigation Control

Abstract

The deployment of smart irrigation technologies in rural and remote agricultural regions remains limited by unreliable electrical infrastructure, restricted Internet connectivity, and the high energy demand of Internet of Things (IoT) platforms. This study presents the design and experimental validation of an energy-optimized IoT irrigation system powered by a photovoltaic (PV)-battery subsystem for off-grid agricultural applications. The proposed architecture integrates multi-parameter environmental sensing, GSM/GPRS communication using the MQTT protocol, cloud supervision through the ThingsBoard platform, and local as well as remote irrigation actuation. To improve energy autonomy, the system combines duty-cycled operation, Arduino sleep-mode management, hardware-level sensor power switching through MOSFET control, and corrected PV-battery sizing. Experimental validation under real agricultural conditions demonstrated continuous autonomous operation during a seven-day deployment, with an effective duty cycle of 6.7%, successful telemetry transmission of approximately 96.8%, and more than two days of estimated battery autonomy without solar input. The developed platform enabled real-time environmental monitoring and remote irrigation supervision while maintaining low energy demand under off-grid conditions. The main contribution of this work lies in the integrated implementation of low-cost sensing, cellular IoT communication, and energy-aware system management within a unified architecture adapted to isolated agricultural environments. These findings demonstrate the feasibility of affordable and energy-autonomous IoT irrigation systems for smart agriculture in regions where access to conventional power and broadband infrastructure remains limited.