Design and Fabrication of a Parabolic Trough Collector Prototype for Solar Thermal Applications in Alice, South Africa

Renewable energy technologies are increasingly recognized as essential solutions for mitigating energy insecurity and supporting sustainable development. Among solar thermal systems, parabolic trough collectors (PTCs) have attracted significant attention for medium-temperature heat generation due to their high optical concentration ratio and thermal conversion efficiency. However, the deployment of small-scale PTC systems in rural and resource-constrained regions remains limited due to high manufacturing costs, inadequate local designs, and insufficient experimental data on performance under African climatic conditions. This study presents the novel design, fabrication, and experimental evaluation of a low-cost small-scale PTC prototype specifically developed for the climatic conditions of Alice, South Africa. Unlike conventional systems primarily optimized for large-scale industrial applications, the proposed prototype integrates locally adaptable design parameters, including a 90° rim angle and a compact aperture width of 1.072 m, to enhance thermal performance while reducing fabrication complexity and material costs. The thermal performance of the system was experimentally evaluated using a CR1000 data acquisition system to continuously monitor solar irradiance, inlet and outlet fluid temperatures, ambient temperature, and wind conditions under real outdoor operating environments. The prototype achieved a peak thermal efficiency of 35% under a maximum global horizontal irradiance (GHI) of 470 W/m2, demonstrating the technical feasibility of decentralized solar thermal energy systems for small-scale applications. The study further provides a detailed assessment of the influence of meteorological parameters on collector performance, revealing that solar irradiance is the dominant factor governing thermal output. In contrast, wind-induced convective heat losses substantially reduce system efficiency. The novelty of this work lies in the experimental validation of a cost-effective PTC design under South African climatic conditions, along with the identification of practical performance-enhancement strategies, including selective absorber coatings and improved thermal insulation, for small-scale solar thermal applications.