Thermal modulation of radiation fields enhancing the adaptability of CPV-Hydrogen systems to hot outdoor conditions

•A novel thermally integrated CPV-coupled EC system is proposed.•Tubular SBS filter capable of spectrally and spatially modulating irradiance.•Irradiation unavailable for PV contributes to higher electrolysis efficiency.•Effective thermal management increases hydrogen production efficiency by 5.2%.•The use of low-cost standard glass pipe facilitates scale-up. Photovoltaic (PV) coupled with water electrolysis (EC) provides a clean and reliable hydrogen supply. However, commercial PV often undergo severe performance degradation under high temperature outdoor conditions. In this work, we report a novel thermally integrated concentrated PV-EC system using a pipeline-based liquid spectral beam splitting (SBS) filter as the electrolyte preheater. Unlike previous designs where heat is collected on the backside of the PV, the liquid-filled tubular SBS filter effectively modulates solar irradiation both spatially and spectrally prior to reaching the PV surface. The infrared wavelengths are absorbed by the electrolyte prior to their conversion into thermochemical losses in the PV, thereby augmenting the temperature and efficiency of electrolysis. Efficient allocation of thermal energy can simultaneously satisfy the lower temperature requirement for PV and the higher temperature demand for EC. The PV surface temperature can be decreased by as high as 23.5 K owing to this thermally integrated mode. The optimized allocation of thermal energy resulted in a notable increase in the average efficiency of photovoltaics, electrolysis, and solar hydrogen production by 7.5%, 8.1%, and 5.2% respectively. As a result, out design can significantly suppress the decreasing trend of efficiency in outdoor experiments during summer midday. The proposed system design, characterized by its simplistic structure and utilization of cost-effective materials, presents a feasible alternative for large-scale solar hydrogen production in hot outdoor environments.