Techno-economic modelling of AEM electrolysis systems to identify ideal current density and aspects requiring further research

Abstract

Hydrogen produced by water electrolysis using renewable energy is a sustainable alternative to steam reformation. As a nascent commercial technology, performance, and economic comparisons of anion exchange membrane water electrolyzers (AEMWE) to other electrolyzer technology benchmarks are not available. We present a techno-economic model estimating AEMWE's baseline levelized cost of hydrogen (LCOH) at $5.79/kg, considering trade-offs between current density, efficiency, stability, capital, and operating costs. The optimal current density is 1.38 A cm−2, balancing stability and performance for the lowest LCOH. Using low-cost electricity and larger stack sizes, AEMWE could achieve $2/kg low-carbon hydrogen. Technical improvements targeting system efficiency, particularly reducing overpotentials in hydrogen and oxygen evolution reactions, could further reduce LCOH to $1.29/kg, approaching U.S. Department of Energy cost targets. There are hopes this model could raise the profile of AEMWE's economic potential to produce green hydrogen and highlight its suitability for decarbonizing the energy sector.