Parabolic Trough Collectors A Review of Technological Development and Performance Evolution

Abstract Parabolic trough collectors (PTCs) are among the most mature and widely deployed technologies in concentrated solar power systems, providing reliable medium- to high-temperature thermal energy for industrial and power generation applications. This review presents a comprehensive assessment of PTC research from 1968 to 2025, covering advances in system design, thermal performance, and advanced integration strategies. The study uses a combined chronological–methodological framework, classifying the literature into experimental, analytical, numerical, and system-level investigations to ensure a structured and consistent evaluation. The analysis shows that early studies established the feasibility of solar steam generation and fundamental design principles, while later research focused on system integration, numerical modeling, and performance optimization. Recent advances emphasize internal heat-transfer enhancement using nanofluids and inserts, as well as hybrid systems that integrate PTCs with photovoltaics, thermoelectric generators, and thermal energy storage. Despite these developments, significant gaps remain in weather-normalized experimental validation, unified thermo-hydraulic performance metrics, and long-term system reliability under real operating conditions. Future research should prioritize integrated experimental–numerical approaches, standardized performance evaluation criteria, and the development of robust, climate-adaptive PTC systems to support sustainable energy applications.