Techno-economic assessment of hybrid solar spectral-splitting PV–thermal green hydrogen production systems

This study presents a comprehensive techno-economic assessment of a spectral-splitting photovoltaic-thermal hydrogen system across diverse climatic zones in Karlsruhe, Barcelona, Cairo and Dunhuang. By integrating optical-thermal simulations with an economic model, the analysis quantifies the impact of geography and tracking strategies on techno-economic performance. Results demonstrate a peak annual solar-to-hydrogen efficiency of around 20 % in high-irradiance regions like Cairo; specifically, while Cairo achieved the highest summer production yields, Dunhuang exhibited a unique profile that mitigates seasonal fluctuations, resulting in comparatively uniform hydrogen production throughout the year. The comparative analysis demonstrates that the substantial gain in hydrogen yield from dual axis tracking outweighs the incremental hardware costs. This establishes dual axis tracking as the economic optimum, reducing the levelized cost of hydrogen (LCOH) to 6.0 €/kg, approximately 9.6 % lower than the single axis baseline. Furthermore, Monte Carlo uncertainty analysis confirms that deploying the system in high-irradiance sites significantly compresses investment risk. Under hydrogen-only revenue situations, the discounted payback time (PBT) is around 6 years for dual axis configurations in Cairo and Dunhuang, while commercial valorisation of the oxygen byproduct accelerates capital recovery, reducing the PBT to around 5 years in Cairo.