Energy and exergy analyses of integrated hydrogen production system using high temperature steam electrolysis

•Thermodynamic performance assessment of solar-driven integrated HTSE for hydrogen production is discussed.•Energy and exergy efficiencies are found to be 24.79% and 22.36% for power generation section.•Energy and exergy efficiencies for hydrogen production sections are found to be 87% and 88%, respectively.•H2 generation was obtained as 0.057 kg/s.

In this study, thermodynamic performance assessment of solar-driven integrated HTSE for hydrogen production is discussed in detail. The system consists of a solar tower, Brayton cycle, Rankine cycle, organic Rankine cycle (ORC) and high temperature steam electrolysis (HTSE). The required heat energy for power generation cycles are supplied from solar energy while produced electricity is used for the necessary energy demand of HTSE. For the analyses, the inlet and outlet energy and exergy rates of all subsystems are calculated and illustrated accordingly. From the results of the analyses, the overall energy and exergy efficiencies of the considered system are found to be 24.79% and 22.36% for power generation section and 87% and 88% for hydrogen production section respectively. Also it is found that without any auxiliary equipment, the considered hydrogen production process consumes 1.98 kWhe at 230 °C, generates 0.057 kg/s H2.