Hydrogen generation from a small-scale solar photovoltaic thermal (PV/T) electrolyzer system: numerical model and experimental verification

Abstract

In this study, the electrical, electrochemical and thermodynamic performance of a PV/T electrolyzer system was investigated, and the experimental results were verified with a numerical model. The annual amounts of electrical and thermal energy from the PV/T electrolyzer system were calculated as 556.8 kWh and 1912 kWh, respectively. In addition, the hydrogen production performance for the PV/T electrolyzer was compared with that of a PV electrolyzer system. The amount of hydrogen was calculated as 3.96 kg annually for the PV system, while this value was calculated as 4.49 kg for the PV/T system. Furthermore, the amount of hydrogen production was calculated as 4.59 kg for a 65 degrees C operation temperature. The electrical, thermal and total energy efficiencies of the PV/T system, which were obtained hourly on a daily basis, were calculated and varied between 12-13.8%, 36.1-45.2% and 49.1-58.4%, respectively. The hourly exergy analyses were also carried out on a daily basis and the results showed that the exergy efficiencies changed between 13.8-14.32%. The change in the electrolysis voltage was investigated by changing the current and temperature in the ranges of 200-1600 mA/cm(2) A and 30-65 degrees C, respectively. While the current and the water temperature varied in the ranges of 400-2350 mA/cm(2) and 28.1-45.8 degrees C respectively, energy efficiency and exergy efficiency were in the ranges of 57.85-69.45% and 71.1-79.7%, respectively.