Investigating proton exchange membrane electrolyzer performance under variable renewable power: Insights into voltage and stack efficiency

Abstract

This study investigates the short-term performance and efficiency of a benchtop proton exchange membrane (PEM) electrolyzer for hydrogen production under dynamic power input conditions representative of renewable energy sources. Experiments were conducted to evaluate the effects of current fluctuation characteristics—specifically frequency and standard deviation—on electrolyzer behavior. Results demonstrate that rapid and high-amplitude current fluctuations lead to increased power consumption, voltage instability, and reductions in both stack and voltage efficiency when compared to steady-state operation. Smoother current profiles, characterized by lower standard deviations and lower frequencies, improved system stability, efficiency, and hydrogen production rates. Additionally, fully transient tests using real wind power profiles revealed the highest power consumption and operational variability, underscoring the challenges posed by fluctuating renewable inputs. While the findings provide valuable insights into the immediate response of PEM electrolyzers under dynamic conditions, they are limited to short-term observations. Further long-duration studies are necessary to evaluate long-term stability and degradation effects. Overall, this research contributes to the understanding of PEM electrolyzer integration with intermittent renewable energy sources and highlights the importance of power regulation strategies for improving efficiency and operational stability in hydrogen production systems.