Experimental Evaluation of a Photovoltaic Powered DC Heating System with Closed-Loop Temperature Control for a Hybrid Dryer

Article at a glance

Journal

Global Journal of Engineering and Technology Research (GJETR)

Published

11 November 2026

Volume / issue / pages

Vol. 2, Issue 11, pp. 693-701

ISSN

3051-3782 (online) · 3051-3774 (print)

Licence

CC BY 4.0 — free to read and reuse with attribution

Peer review

Double-blind, at least two independent reviewers

Publisher

EP Journals Group

Abstract

Photovoltaic (PV)-powered electrical heating can provide a fast and controllable auxiliary heat source for hybrid agricultural dryers, but its effectiveness depends on stable DC power conversion and accurate thermal feedback. This study experimentally evaluates a PV-powered direct-current heating subsystem integrated into a modular hybrid dryer. The electrical subsystem used two 350 W PV modules in parallel, an adjustable 800 W DC–DC converter, and a 600 W, 35 V resistive heater. Chamber temperature was regulated by thermistor feedback through an SG3524 PWM controller, C1815 driver transistor and IRFP4468 MOSFET switching stage. The high-power heater was supplied directly from the PV array through the regulated converter, while the auxiliary battery served the low-power fan and control circuits. Measurements were recorded at 15-min intervals during a five-hour electrical control test and an eight-hour plantain drying experiment. Converter input voltage varied from 28.50 to 33.71 V while output voltage remained within 34.70– 35.00 V. Mean converter efficiency was 91.30% with a standard deviation of 0.29% and coefficient of variation of 0.32%. Mean steady-state heater power was 600.13 W, with a standard deviation of 1.97 W and coefficient of variation of 0.33%. Chamber temperature increased from 30.4 to 59.7 °C within approximately one hour and subsequently remained near the 60 °C set-point, giving a steady-state mean of 60.13 °C, standard deviation of 0.11 °C, coefficient of variation of 0.18%, mean absolute temperature error of 0.13 °C and maximum absolute deviation of 0.30 °C. In the associated drying test, 10 kg of fresh plantain at 65% wet-basis moisture content was reduced to approximately 10% in 8 h, with the maximum interval drying rate of 1.29 kg h−1 occurring at 1.75 h. The results demonstrate that direct PV-to-DC heating, when coupled with regulated power conversion and closed-loop electronic control, can provide a stable and responsive auxiliary heat source for modular hybrid drying.

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