Design Optimization and Performance Evaluation of Solar Parabolic Trough Collectors: Comparative Analysis of Receiver Materials and Heat Transfer Fluids

AbstractSolar parabolic trough collectors (PTCs) have emerged as one of the most promisingconcentrated solar power (CSP) technologies, accounting for over 80% of global CSPinstallations. This study presents a comprehensive experimental investigation into the design optimization and performance evaluation of small-scale PTCs based on a three-year field study (2022–2024). The research systematically evaluates the impact of receiver pipe materials (copper and aluminum), reflector sheet materials (aluminum mirror andsilvered glass), and heat transfer fluids (water and ethylene glycol-water mixture) onthermal, collector, and optical efficiencies. A 4 m2 aperture area prototype was testedunder standard Indian climatic conditions in Indore, Madhya Pradesh. Resultsdemonstrate that copper-silvered glass configurations with ethylene glycol-water achievedthe highest thermal efficiency of 52.8%, while the collector efficiency peaked at 75% withcopper-silvered glass-water combinations. Optical efficiency remained stable at 71.35%for silvered glass reflectors compared to 64.52% for aluminum mirrors. The study revealssignificant seasonal variations, with April and March registering peak thermal and collector efficiencies, respectively. This investigation addresses critical gaps in long-duration PTC performance analysis and provides empirical evidence for material selection optimization in tropical climates. The findings contribute to advancing cost-effective,high-efficiency CSP systems suitable for industrial heating and power generationapplications in solar-rich regions.