Design and implementation of an intelligent remote monitoring and control system for enhancing hybrid solar-electric dryer (HSED) performance

This paper presents a robust remote monitoring and control architecture for a Hybrid Solar-Electric Dryer (HSED), designed to optimize the drying process of high-moisture agricultural products under controlled conditions. The system integrates real-time Proportional-integral-derivative (PID) control for temperature regulation, enabling precise actuation of heating elements. Data acquisition and communication are implemented via the Message queuing telemetry transport (MQTT) protocol, facilitating interoperability between LabVIEW, a Crio9030 programmable logic control (PLC), a local server, and a web-based interface for remote supervision. Experimental validation involved drying tests at 40, 50, 60, and 70 °C, both unloaded and with a 4 kg fig load. The HSED consistently maintained target temperatures and demonstrated a specific energy consumption (SEC) of 0.70 kWh/kg and peak drying efficiency of 89% at 70 °C. At this temperature, the system relied on a solar energy fraction (SEF) of 42.3% and electric energy fraction (EEF) of 57.7%. The proposed solution demonstrates strong potential for energy efficiency, cost-effectiveness, and scalable remote operation in agrifood drying systems.