Stack economics will decide whether green hydrogen wins.

Most public discussion of green hydrogen starts from the price of renewable electricity. This is the wrong place to start. Electricity cost is already low enough in the better wind and solar markets, and is falling faster than electrolyser cost. The real rate-limit is the stack itself — its capital cost per kilowatt, and the number of hours it can run before it degrades.

What the cost curve actually looks like

Two thirds of the levelised cost of green hydrogen is the electrolyser capex amortised over its running hours. That is very different from renewable power, where capital cost is a minority of the total. It means that a ten percent improvement in stack durability is worth more than a ten percent fall in electricity price.

Alkaline electrolysers are the mature technology. PEM is the dense, high-pressure option favoured by mobility applications. Solid-oxide (SOEC) is the efficiency leader, but only economically compelling when waste heat is available — which means industrial co-siting.

Where the defensible investments sit

We look for stack-level chemistry that changes the slope of the cost curve rather than its intercept — catalysts that survive longer cycles, membranes that tolerate impure water, cell designs that reduce iridium or nickel loading without sacrificing efficiency. This is slow engineering, not software engineering.

We are cautious about 'hydrogen platforms' whose defensibility is a project-development pipeline rather than a piece of technology. The pipeline will not be defensible for long; the technology, if it is real, will be.

What we are watching

European and Gulf region industrial-scale deployments through 2027 will settle most of the open questions. Gigawatt-class projects in Germany, the Netherlands, and the Middle East are the first real test of stack durability outside a laboratory. We will be reading those reports closely.