Abstract

Access to reliable cooling services remains limited in off-grid, arid regions, despite their high solar energy potential. In sub-Saharan Africa, only a small fraction of farmers have access to reliable cold storage, and conventional refrigeration often relies on electricity and refrigerants with high ozone depletion potential or global warming potential. Solar-powered absorption refrigerators, which utilize thermal energy instead of compressors and non-toxic refrigerants, provide a cleaner alternative. This study examined a 30-L single-effect solar-vapor absorption refrigerator (with 25kg capacity) using cyclopentane as the refrigerant. The system was powered by a 350W photovoltaic panel, a battery (12V, 200Ah), a Direct Current heater, and a controller. Field tests were conducted in off-grid Turkana, Kenya, under two scenarios: a no-load (empty cabinet) scenario and a realistic load (bottled water) scenario. Temperatures at the generator, evaporator, condenser, cabinet, and ambient were logged, and solar irradiance was measured. From this data, the cooling Coefficient of Performance (COP) and system efficiency were calculated. Under no-load, the cabinet reached 4.3°C (from 36°C ambient) and achieved a COP of 0.091; under load, the cabinet reached 8.6°C with a COP of 0.105. The system efficiency was 78.6%. These results demonstrate that even with modest input power, the solar-driven absorption refrigerator can maintain temperatures above freezing, suitable for vaccine or food storage in off-grid communities.