Recent Progress and Challenges in Hybrid Water Electrolysis through Economic Evaluation

Water electrolysis is a sustainable method of hydrogen production with low levels of CO₂ emissions. However, the problem of high economic costs must be resolved. Hybrid water electrolysis (HWE), derived by replacing the sluggish oxygen evolution reaction, emerges as an alternative method to reduce power consumption. Recent studies on HWEs have focused on reporting cell potential reductions, but their impact on hydrogen production costs is still unclear. In this paper, power consumption and levelized cost of hydrogen (LCOH) were evaluated to understand the economic impact of HWEs. Among various HWEs, HzOR showed an excellent energy consumption reduction (43.3 kWh/kg) resulting in the lowest LCOH ($1.92 kg^–1). These results prove one of the most effective alternatives to water electrolysis in its current state. Although other HWEs show only small reductions in energy consumption and LCOH in their current state, these reactions still show high potential to reduce energy consumption and LCOH.