Adaptive and Stepwise Solar Tracking Systems in Flat-Plate and Tubular Collectors: A Comprehensive Review of Thermal Performance, Modeling, and Techno-Economic Perspectives

Solar thermal collectors remain a fundamental component of renewable heat generation in the building sector. Recent progress in solar tracking technologies has led to the emergence of adaptive and stepwise tracking systems that enhance radiation capture while maintaining low mechanical and energy demands. This review comprehensively synthesizes current knowledge on the design, modeling, and performance evaluation of such systems, with emphasis on their role in building decarbonization and techno-economic feasibility. The classification of collectors is revisited to highlight the relationship between optical concentration, tracking precision, and thermal output. Comparative studies indicate that adaptive and stepwise tracking strategies improve annual energy yield by 20–35% compared to fixed systems, while reducing the levelized cost of heat (LCOH) by up to 15%. Modeling approaches integrating optical and thermal domains are discussed alongside emerging applications of artificial intelligence, predictive control, and IoT-based monitoring. The paper concludes with an outlook on future research directions, focusing on durability, standardization, and digital integration of solar thermal systems in smart buildings. Overall, adaptive tracking technologies represent a promising pathway toward efficient and sustainable solar heat utilization in the context of global energy transition.