The impact of degradation on the economics of green hydrogen

Abstract

The production of green hydrogen through renewable energy is increasingly recognized as a viable alternative to fossil fuels in efforts towards global decarbonization. Alkaline water electrolysis, notable for its long operational history and scalability, is a pivotal technology in the mass production of green hydrogen. However, the variability of renewable energy sources presents significant challenges, particularly the frequent on/off operations that accelerate degradation of the electrolysis stack. This study assesses how degradation caused by the instability of renewable energy sources impacts the economic feasibility and productivity of alkaline water electrolysis under. A comprehensive model is developed to forecast efficiency declines in hydrogen production due to degradation and to evaluate renewable energy outputs using meteorological data. Economic viability is analyzed through various scenarios using the levelized cost of hydrogen. Initial results reveal substantial economic and productivity losses when degradation is considered, compared to non-degradation scenarios. The integration of multiple types of renewable sources reduces variability and thus mitigates degradation to some extent. While battery integration stabilizes renewable energy, economic challenges persist due to high costs despite reduced on/off cycles. The study also explores the trade-offs between economic factors and the frequency of stack replacements, generating optimal replacement schedules across different efficiency settings. The sensitivity analysis underscores the significant influence of degradation on productivity and economic outcomes, as well as the uncertainties related to cost and meteorological data.