Hydrogen production with a photovoltaic thermal system enhanced by phase change materials, Shiraz, Iran case study

Abstract

Whereas Photovoltaic Thermal Systems (PVT), Phase Change Materials (PCM) and Proton Exchange Membrane (PEM) electrolyzer have been thoroughly studied individually, the effects of their combination need to be more investigated. The current study proposed a new PVT system integrated with PCM and PEM electrolyzer to produce hydrogen in a hydrogen fuel filling station. Based on the energy and exergy balance equations, a mathematical model is developed to analyse the effects of different types of PV and PCM sets on the thermal and electrical performances. Variations in the temperature of system components, generated electricity, hydrogen production as well as the energy/exergy amounts and efficiencies with time are presented for different effective parameters. Based on the obtained results, we found that PV type is one of the most dominant parameters of the system. PCM utilization improves the electrical, thermal energies and exergy efficiencies. The highest daily amount of produced hydrogen is obtained for 16th August 2018 with mono-crystalline semitransparent PV and 120 kg of RT35 PCM type (88.71 gr/day). While the hydrogen production for the same PVT system without PCM is 5.32% less than the case with PCM. Moreover, the maximum diurnal energy efficiency is obtained 35.04% for mono-crystalline semitransparent PV and RT35 PCM during the summer, while the maximum daily exergy efficiency of 15.17% is achieved for the integration of mono-crystalline semitransparent PV and RT28 PCM type in the winter.