Dynamic optimization of proton exchange membrane water electrolyzers considering usage-based degradation

Abstract

We present a techno-economic optimization model for the design and dynamic operation of proton exchange membrane (PEM) electrolyzers, for enabling cost-effective hydrogen production. This model integrates a 0-D model of the electrolyzer stack, process-wide mass and energy balances, operational constraints, and an empirical relation to characterize degradation as a function of operating current density. Utilizing a decomposition-based solution approach, the model predicts optimal electrolyzer size, operation, and necessary hydrogen storage to satisfy hydrogen demand across various technology and electricity price scenarios. Analysis for 2022 electricity prices and technology costs shows that including use-dependent degradation raises the levelized cost of hydrogen (LCOH) from $4.56/kg to $6.60/kg and increases frequency of stack replacement (2 vs. 7 years). However, by 2030, we anticipate a significant reduction in LCOH to $2.50/kg due to lower capital expenses, leading to longer stack lifetimes and less hydrogen storage. The proposed modeling framework is adaptable to study other electrochemical systems relevant for decarbonization.