Techno-economic analysis and Monte Carlo simulation of green hydrogen production technology through various water electrolysis technologies

The green hydrogen produced by water electrolysis combined with renewable energy is inevitable for a sustainable and clean energy society. However, the green hydrogen production cost is still more expensive than fossil fuel-based methods such as steam methane reforming and it is the biggest challenge. In this study, to determine the most economical way to obtain green hydrogen, a technoeconomic analysis was performed on four different water electrolysis technologies, that is, alkaline water electrolysis (AWE), proton exchange membrane electrolysis (PEMEC), solid oxide electrolysis with electric heaters (SOEC (E.H)), and solid oxide electrolysis combined with a waste heat source (SOEC (W.H)). It is assumed that the SOEC (W.H) system is linked to the adjacent power plant and receives waste heat. The net present value calculation, sensitivity analysis, and Monte Carlo method were performed for the 4 cases presented above. Calculated unit hydrogen production cost was 7.60, 8.55, 10.16, and 7.16 $/kg(H2) for AWE, PEMEC, SOEC (E.H), and SOEC (W.H), respectively. The analysis results show that the SOEC (W.H) has the most competitive case due to sensible heat energy saving and higher stack efficiency. Sensitivity analysis determined the most influential cost factor, and consequently, it seems necessary to reduce capital costs along with subsidizing electricity costs and tax rates to compete with gray hydrogen.