Comparative techno-economic evaluation of alkaline and proton exchange membrane electrolysis for hydrogen production amidst renewable energy source volatility

Abstract

This study explores the economic feasibility of two leading electrolysis technologies—alkaline electrolysis and proton exchange membrane electrolysis—in the context of rapid temporal fluctuations from renewable energy sources. Alkaline electrolysis currently benefits from its relative maturity and established economic advantages. On the other hand, proton exchange membrane electrolysis offers enhanced operational flexibility and substantial potential for technological advancements that could significantly improve its economic viability and efficiency over the long term. Comprehensive process models of various system components are developed to evaluate the impact of minimum load requirements on these systems and explore strategies to mitigate these effects. Initially more economically viable, alkaline electrolysis could see its advantage shift with the strategic integration of batteries to reduce on/off operations and the implementation of overload operations, compared to proton exchange membrane electrolysis. A sensitivity analysis confirms the future competitiveness of these technologies, considering anticipated technological improvements, the influence of key economic variables, multi-year variability in weather patterns, and the impacts of maintenance requirements and system downtime associated with frequent on/off cycles.