Optimal solar power for control of smart irrigation system

Abstract

Irrigation is very vital to food security but deployment of effective irrigation requires solar energy especially in the rural areas with no grid power. In this work, the optimal power required in the solar photovoltaic (PV) and the battery of a solar powered system (at any instance) for effective operation of a smart irrigation facility in Elizade University Ilara Mokin, Nigeria is determined. The system uses current and voltage sensors placed at the solar photovoltaic (PV) and the battery sections to perform real-time measurements on irrigation solenoid valves. Acquired current and voltage sensor values are passed to a microcontroller, readable in the computer serial monitor and later used to compute the required power in both PV and battery sections. The developed solar power system was implemented on a pilot farm with irrigation facilities consisting of sensors (moisture content, water level) and actuators (three solenoid valves). Tests were performed under the load-on condition. Results obtained reveal a maximum power threshold of 72.68 W for the solar PV and 14 W for the battery when three solenoid valves were loaded or operated at the same time and a minimum value of 31.55 W for the solar PV and 1.9 W for the battery when one valve is operated. The power thresholds obtained would be useful for configuring the smart irrigation system controller to ensure adequate delivery of water to crops as well as prolong the lifespan of the developed solar powered system.