Experimental Performance Evaluation of a Low-Cost Cylindrical Solar Concentrator for Thermal Cooking Applications in a Tropical Climate

Abstract

Access to clean and affordable cooking energy remains a challenge in developing regions, particularly in sub-Saharan Africa, where traditional biomass fuels are widely used and are associated with environmental and health concerns. Solar cooking provides a renewable alternative; however, the practical application of low-cost cylindrical solar concentrators for cooking under fluctuating tropical weather conditions remains insufficiently evaluated. This study presents the design and experimental performance evaluation of a low-cost, manually tracked cylindrical solar concentrator intended for cooking applications. The concentrator features an aluminium reflector with a 1.2 m² aperture area and a geometric concentration ratio of 12. Experimental tests conducted during the rainy season under fluctuating solar irradiance assessed the system's thermal performance using water and cottonseed oil as heat-transfer fluids. The system achieved maximum fluid temperatures of 130 °C for oil and 67 °C for water. The calculated average thermal efficiencies for oil during separate tests were 15.32% and 21.12%, while those for water ranged from 12.04% to 19.86%. In the context of sub-Saharan Africa, these technologies offer a viable solution for achieving cooking temperatures ranging from 150 °C to 300 °C while helping to reduce deforestation. The results demonstrate that, despite suboptimal weather conditions, the cylindrical solar concentrator exhibits a significant capacity for solar-to-heat conversion, supporting its potential as a viable and sustainable cooking solution. Further design improvements and testing during the dry season are recommended to optimise performance.