Author:
Pele Igho Ewho, Timothy Eghosa Okuonghae

Doi: 10.26480/jtin.01.2025.28.32

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

A reliable cooling solution is critically needed but often unavailable in off-grid areas of sub-Saharan Africa, where persistent energy shortages and unstable power supply create a major obstacle for food preservation and storing vaccines. This study demonstrates a practical method for addressing this problem by retrofitting a standard AC refrigerator to run on solar-power using a Variable Speed Direct Current (VSDC) compressor. A 112L Haier Thermocool refrigerator was retrofitted with a ZH15G DC compressor, powered by a 300W monocrystalline solar panel, a 20A MPPT controller, and a 12V, 75Ah battery. The DC system cooled from 25°C to −3.2°C in 9 minutes, consuming 180 Wh/day—91.88% less than the AC system’s 2,217.6 Wh/day. The conversion cost (₦310,000) was 36.7% lower than a new DC refrigerator (₦489,993), with a payback period of 3.55 years and an annual CO₂ reduction of 297.49 kg. Validated by a lumped capacitance thermal model, this scalable, cost-effective solution supports Sustainable Development Goals (SDGs) 7 and 13, addressing energy poverty in off-grid communities.