Analysis of H2 production with zero carbon emissions from an integrated multi-energy system

This study presents a novel multi-energy and hydrogen production system by integrating flat-plate photovoltaic thermal (FP PV/T) and proton exchange membrane (PEM) electrolyzer to produce green hydrogen, electrical and thermal energy. Experimental analysis indicates that electrolyzer efficiency improves with higher inlet water temperature and applied current density. Optimally, PEM water electrolyzer performs the best with a membrane thickness of 300 mu m. Unlike conventional solar driven PEM system, the novel system harnesses both electrical and thermal energy, enhancing the overall efficiency. Cooling provided by circulating water in the FP PV/T unit reduces PV cell temperature, thereby increasing both electrical efficiency and hydrogen output. The system achieves an electrolyzer efficiency of 86.73%. In simultaneous heat and hydrogen production mode of novel system, the overall average solar energy utilization efficiency, hydrogen production efficiency, hydrogen production capacity, and thermal efficiency from one day data are 25.52%, 10.01%, 1299.33L, and 15.51% respectively. The relative errors in hydrogen production efficiency, photovoltaic electrical efficiency, electrolyzer efficiency, and hydrogen production are 7%, 1.4%, 5.8%, and 5.8% respectively. The novel system has a payback time of 4 years.