Electrolyzer Scale-Up Is a Manufacturing Story

The bottleneck in green hydrogen isn't electrochemistry — PEM and alkaline electrolysis are both mature at small scale — it's manufacturing scale for gigawatt-level deployments. Iridium scarcity constrains PEM capacity; alkaline systems require large, custom-fabricated pressure vessels. Nel Hydrogen, ITM Power, and ThyssenKrupp Nucera are all racing to build GW-scale electrolyzer factories but burning cash in the process, and order books are thinner than 2022 projections suggested. The defensible investment is in electrolyzer stack component manufacturing — membrane electrode assemblies, bipolar plates, catalyst coatings — rather than system integrators, which face commodity-like pricing pressure. Watch ITOCHU and Air Products as strategic acquirers in this space.