Degradation modelling and the impact of intermittent operation on proton exchange membrane electrolyzers

This paper investigates membrane thinning with fluoride release rate as the indicator for chemical degradation in PEM electrolyzers when coupled with intermittent energy sources. Continuous and intermittent operating scenarios are modelled to predict and compare chemical degradation over long-term operation. Predicted degradation is less for continuous operation (with a rate of 2.69 nm h −1 ), whereas intermittent operation increases the predicted degradation rate to 5.86 nm h −1 . Four distinct intermittency patterns over a 48-h period are also investigated, highlighting the role of downtime and scheduling on degradation. Results indicate that differences in cumulative degradation are primarily determined by the length and sequencing of OFF periods. The results provide insights into operational strategies, indicating that accounting for electrolyzer performance degradation in operational planning can mitigate degradation and improve performance in intermittent renewable energy applications. • Predictions over the operational life of a PEM electrolyzer with intermittent use. • Intermittent operation is significant for membrane degradation. • Intermittent operation causes non-linear membrane degradation. • Irregular cycling can increase predicted membrane thinning.