Development of a Dual-Mode DC-Operating Corn Thresher for Small-Scale Production

Abstract

This study presents the design, fabrication, and performance evaluation of a dual-mode DC corn thresher powered by either direct battery or direct solar energy. The system was developed to reduce post-harvest losses, improve labor efficiency, and minimize fuel dependency among smallholder farmers through renewable energy integration. It is driven by a 450 W, 24 V brushless DC motor supported by a 600 W photovoltaic array, a 120 Ah deep-cycle battery, and a 30 A MPPT charge controller. Experimental results showed an optimal throughput of 110 kg/h at 1,400 rpm, achieving an average threshing efficiency of 98.55% with kernel damage below 2.5%. The battery enabled 3.8 hours of continuous operation, while the solar subsystem restored full charge within four hours under standard irradiance. Energy consumption was 0.40 kWh per 100 kg of corn—approximately 38% lower than diesel-powered alternatives. With a total cost of ₱44,500, a payback period of 0.65 years, and a benefit–cost ratio of 1.55, the system demonstrates strong financial feasibility and offers a sustainable, cost-effective solution for renewable-powered rural mechanization.