Tackling uncertainty in electrolyser deployment: the role of degradation on expansion planning problems

Abstract

Uncertainties surrounding the long-run cost-benefit of hydrogen hybrid plants (i.e., dedicated renewable power, energy storage technologies, and grid connection) are challenging the widespread adoption of electrolysers, hindering the production of green hydrogen on a large scale. Both electrolysers and renewable generation systems require high capital investment. However, weighing only the initial expenditures can be misleading: the technology choices and system operation design have a direct impact on electrolyser efficiency, lifetime, and associated costs. This work presents a multi-period expansion and planning model that can simultaneously determine the investment and operation decisions of a hydrogen hybrid plant at minimum cost. The model is formulated as a mixed-integer linear programming (MILP) problem in hourly resolution and accounts for degradation effects in key system components, including battery storage, solar PV and wind power generation, and PEM electrolysis stacks. The case study, which covers a modelling horizon of 30 years, is based on a real Spanish facility producing hydrogen for use as industrial feedstock. We explicitly address the effects of PEM stack degradation and replacement, providing insights into its implications for investment strategies, operational performance, and the levelised cost of hydrogen.