The growing demand for sustainable hydrogen has increased interest in solar-driven hybrid systems, particularly in high- irradiance regions. This study compares two hydrogen production pathways integrated with a concentrating photovoltaic/thermal (CPV/T) system: high-temperature electrolysis using a solid oxide electrolyzer cell (SOEC) and a magnesium–chlorine (Mg–Cl) thermochemical cycle. A transient thermo-electrical model of the CPV/T receiver was applied using hourly typical meteorological year data for Ouargla, Algeria, capturing realistic daily and seasonal variations. The CPV/T system achieved peak thermal and electrical outputs of 187 and 71 W/m2, maintaining total efficiencies above 42%. Coupled to hydrogen units, the SOEC pathway delivered higher annual hydrogen yields (4.38 kg H2/m2) than the Mg–Cl cycle (2.78 kg H2/m2), benefiting from simultaneous utilization of thermal and electrical energy. Key parameter sensitivities, including direct normal irradiance (DNI), collector concentration, electrolyzer efficiency, and heat exchanger performance, indicate that the SOEC advantage is robust under realistic variations. Preliminary economic assessment using levelized cost of hydrogen shows that, despite higher electrolyzer costs, the SOEC pathway's superior productivity and compact design reduce specific hydrogen costs compared to the Mg–Cl route, which requires larger solar fields. These results confirm that CPV/T-based hybrid systems are well-suited for scalable solar hydrogen production in desert climates, with SOEC offering the most favorable techno-economic performance, while Mg–Cl remains attractive for heat-driven applications.
Gueridi et al. (Sun,) studied this question.