Green Hydrogen Production with 25 kW Alkaline Electrolyzer Pilot Plant Shows Hydrogen Flow Rate Exponential Asymptotic Behavior with the Stack Current

Green H2 production using electrolyzer technology is an emerging method in the current mandate, using renewable-based power sources integrated with electrolyzer technology. Prior research has been extensively studied to understand the effects of intermittent power sources on the hydrogen production output. However, in this context, the characteristics of the working electrolyzer behave differently under system-level operation. In this paper, we investigated a 25 kW alkaline electrolyzer for its stack performance in terms of stack efficiency, the stack current vs. stack voltage, and the relationship between the H2 flow rate and stack current. It was found that the current of 52 A produces the best system efficiency of 64% under full load operation for 1 h. The H2 flow rate behaves in an exponential asymptotic pattern, and it is also found that the ramp-up time for hydrogen generation by the electrolyzer is significantly low, thus marking it as an efficient option for producing green hydrogen with the input of a hybrid grid and renewable PV-based power sources. Hydrogen production techno-economic analysis has been conducted, and the LCOH is found to be on the higher side for the current electrolyzer under investigation.