The growing demand for sustainable and environmentally friendly energy systems has accelerated the development of solar thermal technologies for domestic applications. This study presents the design, fabrication, and experimental performance evaluation of a parabolic trough collector (PTC) for domestic water heating. The collector employs a line-focus parabolic reflector to concentrate solar radiation onto a receiver tube positioned along the focal line. A prototype PTC was fabricated using a mild steel support structure and polished aluminum reflective sheets. Three receiver tube configurations stainless steel (SS), copper (Cu), and black-coated stainless steel (BC-SS) were experimentally investigated under identical environmental conditions. Key performance parameters, including inlet temperature, outlet temperature, ambient temperature, and solar radiation intensity, were recorded and analyzed.
The experimental results indicate that the copper receiver exhibits the highest thermal efficiency due to its superior thermal conductivity. However, the black-coated stainless steel receiver demonstrates a favorable balance between efficiency, durability, and economic feasibility, making it a suitable choice for domestic-scale applications. The study highlights the critical role of material selection and surface treatment in enhancing the thermal performance of parabolic trough collectors.