Hybrid electrolyzer systems: Smart strategy or economic fallacy?

2026-07-07

AI Summary

This study evaluates whether hybrid systems combining alkaline and proton exchange membrane (PEM) electrolyzers can enhance the techno-economic performance of green hydrogen production through complementary advantages. Challenging the conventional assumption of technology lock-in, the authors employ a parameter-decoupling approach integrated with a techno-economic optimization model, multi-scenario simulations—encompassing variations in electricity prices, storage costs, and renewable energy availability—and large-scale sensitivity analyses to systematically compare the levelized cost, system configuration, and operational scheduling of hybrid versus single-technology electrolysis systems. The results indicate that hybrid configurations are optimal in no more than 5.0% of the scenarios examined, yielding a maximum cost advantage of merely €0.057 per kilogram of hydrogen—approximately 1% of total production costs—thereby casting significant doubt on the prevailing optimism surrounding hybrid electrolysis pathways.

Abstract

Hybrid electrolyzer systems combining alkaline water electrolysis and proton exchange membrane water electrolysis have been investigated in the literature motivated by the expectation that their contrary techno-economic characteristics compensate for the individual technical and economic restrictions of each technology, thereby improving the profitability of green hydrogen production. To reassess the economic potential of hybrid electrolyzer systems beyond these technology-specific assumptions, we independently vary two key characteristics, electrolyzer efficiency and investment cost, in a large-scale sensitivity analysis. For each generated parameter configuration, we performed a techno-economic optimization of a green hydrogen supply chain, including two electrolyzers. The resulting system design, cost objective, and dispatch behavior are subsequently analyzed. Consequently, hybrid electrolyzer systems are identified as optimal if they provide a cost benefit over single electrolyzer systems. The analysis reveals that hybrid electrolyzer systems represent the optimal solution in at most 5.0% of the investigated cases. Furthermore, the maximum cost benefit is 0.057 EUR/kgH2, which corresponds to only about 1% of the total green hydrogen production cost. Additional analyses considering variations in energy purchase prices, storage fees, availability of renewable energy, and baseline electrolyzer efficiency yield negligible changes to these results. Hence, considering that hybrid electrolyzer systems offer marginal cost benefits and prove economically optimal in very few cases, they seem more likely to represent an economic fallacy than a smart strategy.

Problem

• hybrid electrolyzer systems
• green hydrogen production
• techno-economic analysis
• alkaline water electrolysis
• proton exchange membrane water electrolysis

Innovation

• hybrid electrolyzer systems
• techno-economic optimization
• green hydrogen
• sensitivity analysis
• alkaline water electrolysis