Advances in receiver technologies and thermal loss mitigation for solar power tower systems: a comprehensive review

Solar power tower (SPT) systems represent a leading technology for achieving dispatchable and high-efficiency renewable energy generation. This review presents a detailed evaluation of recent advancements in receiver technologies and thermal loss mitigation strategies specific to SPT applications. Four major receiver types, namely external tubular, cavity tubular, volumetric, and particle receivers, are critically compared in terms of thermal performance, structural durability, and geometric innovation. Thermal-loss mechanisms including radiative, convective, conductive, reflection and spillage are analyzed for each receiver class and linked to targeted mitigation methods such as selective coatings, air curtains/partial windows, geometry optimization (fins, cavities, star/fin topologies), and heliostat aiming strategies. The review also summarizes recent progress in high-temperature materials (ceramics, SiC foams, superalloys), internal heat-transfer enhancements (guide vanes, ribbed/compound tubes), and volumetric/particle concepts that enable higher temperatures and integrated thermal storage. Importantly, trade-offs between loss reduction and operational/maintenance burdens (such as auxiliary power for air curtains, coating durability, and aperture-spillage trade-offs) are highlighted. The review consolidates findings from both simulation studies and experimental investigations to present a comprehensive roadmap for enhancing receiver efficiency, extending component lifespan, and supporting the commercial advancement of next-generation SPT systems.