Performance analysis of a PV/T system with metal hydride-based energy storage

This study examines an PV/T solar collector with a Metal Hydride bed for efficient thermal energy storage, using hydrogen as an energy carrier, which has not been previously utilized, to generate electricity and hot water day and night. We included specific application scenarios to illustrate the practical use cases of the system. A 3D- theoretical model has been developed, a calculation Fortran code has been created, and the accuracy of the numerical method has been validated. We simulated the dynamic behavior of the PV/T-MH system and compared it with a standard case without the MH bed. Additionally, the study provides detailed insights into electrical energy output, thermal energy output, heat stored in MH bed, and outlet water temperature. The influence of hydrogen dehydriding pressure and water flow rate during daytime on the system's electrical and thermal performance are comprehensively analyzed. For instance, the findings showed that i) at 2.5 bar dehydriding pressure, 56.7% of the thermal solar energy received by the collector can be stored in the MH bed and reused during the nighttime, ii) the PV/T-MH collector achieves an outlet water temperature about 36% higher than the standard collector, iii) for the standard collector the average conversion efficiency of PV cells (13.88%) is less than the case with MH bed (16.69%), and iv) the average electrical efficiency without MH bed is about 11.02%, however, this efficiency can reach 13.25% when using the proposed PV/T-MH solar collector.