What does your catalyst cost per kilogram of hydrogen?
Enter catalyst performance and an operating point. Get cell voltage, energy consumption, iridium intensity and levelised cost, with every assumption editable. Runs in your browser — no account, nothing stored.
Catalyst
Operating point
System
| LCOH breakdown | €/kg | share |
|---|---|---|
| Electricity | 2.39 | 47 % |
| Capex (amortised) | 1.73 | 34 % |
| Stack replacement | 0.50 | 10 % |
| Fixed opex | 0.51 | 10 % |
Ranges are sensitivity bands (±15 % electricity, ±20 % capex), not confidence intervals. Method v0.1 — open and versioned at /method.
How the model works
Cell voltage is assembled from the reversible potential, the anode overpotential extrapolated to your current density with a Tafel slope, a cathode overpotential, and ohmic loss from the cell's area-specific resistance. That voltage converts to energy per kilogram through Faraday's law — about 26.6 kWh per volt per kilogram — and cost follows from electricity, amortised capex, stack replacement and fixed opex.
What it will not tell you
It will not predict degradation, balance-of-plant detail, grid connection cost, or what your supplier will actually quote. It assumes the Tafel slope holds across the extrapolation, which is a real assumption and not always a safe one.
It is built to compare options on a consistent basis. That is genuinely useful, and it is all it is for.
Questions
What is LCOH?
Levelised cost of hydrogen — the all-in cost per kilogram once electricity, amortised capital, stack replacement and fixed operating costs are spread over the hydrogen produced across the project life. It is the number commercial decisions are actually made on.
Why does catalyst overpotential change the cost?
Overpotential raises the cell voltage needed to drive the same current. Higher cell voltage means more kilowatt-hours per kilogram of hydrogen, and electricity is usually the largest single component of levelised cost. A hundred millivolts is not an academic detail.
Why does iridium loading matter separately?
Iridium is a by-product of platinum mining with roughly 7–8 tonnes of annual primary production. At gigawatt scale, loading per kilowatt becomes a supply constraint rather than a line item, which is why loading reduction is pursued even when it costs a little activity.
Is this model accurate enough to use?
It is a transparent engineering estimate for comparing options on a consistent basis, not a bankable financial model. Every assumption is editable and the method is published. Treat the ranges as sensitivity bands, not confidence intervals.
Do you store what I enter?
No. The calculator runs entirely in your browser. Nothing is sent to a server and no account is needed.
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