Breaking the land-use barrier: A fixed-parabolic mirror system with adaptive tracking for compact solar thermal power

Parabolic trough collectors (PTCs) and Fresnel systems are two dominant approaches in solar thermal energy harvesting; however, both face limitations in terms of land-use efficiency and structural complexity. This study proposes a novel hybrid solar collector that bridges the gap between traditional PTCs and Fresnel configurations by integrating a fixed parabolic reflector with a dynamically adjustable receiver. Unlike conventional PTCs (rotating mirrors with fixed receivers) or Fresnel systems (fixed mirrors with multiple receiver tracking), this design minimizes mutual shading and blocking losses through dense mirror packing while maintaining high optical precision. A three-dimensional Monte Carlo ray tracing model and a two-dimensional heat transfer framework were developed to analyze the optical–thermal performance of the system. The Nelder–Mead optimization algorithm was employed to determine the optimal tracking trajectory of the receiver, achieving an intercept factor exceeding 90 % across broad incidence angles. The results indicate that the compact design increases the annual energy output by 33.5 %, with a paving factor (ratio of mirror area to land area) of 0.7, whereas the land-use efficiency increases by 13.4–55.8 % across seasonal when compared to conventional PTC system. The system achieves higher ground coverage at the expense of introducing a different tracking mechanism. Notably, the system combines the high concentration ratio of PTCs with the land-saving advantages of Fresnel layouts, enables CSP on rooftops or in small fields where conventional troughs are impractical.