HyAxiom / Doosan Fuel Cell PureCell Model 400, hydrogen configuration

The hydrogen build of the PureCell platform, which drops the reformer and gains seven efficiency points

HyAxiom / Doosan Fuel Cell PureCell Model 400, hydrogen configuration is one of 12 fuel cells tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.

HyAxiom PureCell Model 400 hydrogen dossier: 460 kW phosphoric acid at 50% efficiency, zero point-of-generation emissions, purity conflict and inspection notes.

The hydrogen configuration is the same phosphoric acid platform with the fuel processing system removed. On natural gas that system comprises desulfurisation plus steam methane reforming; on pure hydrogen it comes out entirely, and HyAxiom states the modular assembly means removal can be accomplished in a matter of days. The consequences are measurable: electrical efficiency rises from about 44% to roughly 50%, load following improves from 10 to about 20 kW per second, make-up water is no longer required, and the power module drops from 57,000 to 60,000 lb down to 49,428 lb. Output is 460 kW at year 1 falling to 420 kW at year 10, an 8.7% power fade across the stack life, with average lifetime efficiency of 48.3% plus or minus 1.3 against a 50% nameplate. Heat output is 352 kW or 1.20 MMBtu/h to 121 degrees C, equivalent to up to 75 refrigeration tons through absorption chilling in year one. Emissions at the point of generation are zero for carbon dioxide, NOx, SOx, carbon monoxide and volatile organic compounds. Two published figures conflict and a buyer must resolve them before committing. The datasheet states a minimum hydrogen purity of 99.9%, while HyAxiom's current web page states the system can operate with purity as low as 80%. The overhaul scope also differs from the natural gas build: hydrogen needs only the stack overhaul at 10 years, with no fuel processing system overhaul at all, which is the single largest lifecycle cost difference between the two configurations.

Why it matters

The reformer is roughly 20% of system cost and carries its own overhaul, so removing it changes both the capital and the lifecycle equation. Against that, the buyer takes on an NFPA 2 hydrogen storage and piping scope with its own separation distances, which the equipment price does not include. A hydrogen build and a natural gas build of the same machine are therefore not interchangeable assets.

Who buys it

Korean utility and industrial buyers operating under the hydrogen portfolio standard, where a 40 MW long-term service agreement with UH Power runs to 2046, and North American sites with a committed hydrogen supply. The hydrogen build is a shipping product rather than a roadmap item, which is unusual in this category.

Role in the data center

Zero-emission on-site generation where a hydrogen supply exists, with recoverable heat suitable for absorption chilling rather than direct data hall cooling.

Key specifications

Technical summary

Rated output: 460 kW at year 1 (532 kVA at 0.865 power factor) falling to 420 kW at year 10 Electrical efficiency: 50% LHV nameplate; average lifetime 48.3% plus or minus 1.3 Peak overall efficiency: 90% on the datasheet; the Korean page publishes 85% total Heat: 352 kW (1.20 MMBtu/h) to 121 degrees C; up to 75 refrigeration tons via absorption chilling Emissions: zero CO2, NOx, SOx, CO and volatile organic compounds at the point of generation Hydrogen purity: 99.9% minimum on the datasheet against as low as 80% on the current web page Fuel supply: 5 bar gauge plus or minus 0.25; particle size below 1 micron Power module: 29 ft 4 in x 8 ft 7 in x 10 ft 0 in at 49,428 lb, about 10,000 lb lighter than the gas build Load following: about 20 kW per second against 10 on natural gas; no make-up water required Certification: FC 1-2021 North American standard, with UL 1741 SB and IEEE 1547 compliance noted

Pricing and availability

Trend: up

Lifecycle and maintenance

Phosphoric acid systems carry the longest commercial track record in the category, at a 10-year cell stack life against a 20-year product life. The manufacturer publishes power fade from 460 kW at year 1 to 420 kW at year 10, an 8.7% loss, with average lifetime efficiency of 48.3% plus or minus 1.3 against a 50% nameplate on the hydrogen build. The natural gas build adds a fuel processing system, roughly 20% of system cost, that carries its own overhaul, while the hydrogen build removes it and needs only the stack overhaul at 10 years. Doosan is running a funded in-place stack replacement programme across units installed 2020 to 2022, which is a warranty obligation performed by the maker rather than a merchant refurbishment market.

Common failure points

• Phosphoric acid loss — Acid evaporates from the matrix at operating conditions and is carried out in the exhaust
• Cell stack end of life — A 10-year cell stack life dominates residual value and only the maker supplies replacements
• Steady-state decay — Platinum sintering and carbon support corrosion progress against field data out to 60,000 hours
• Start-stop decay — Carbon and catalyst corrosion occur on both shutdown and startup, separate from steady-state decay
• Ammonia contamination — Ammonia induces performance loss and even failure where gas nitrogen exceeds 1% by volume
• Cooler plugging — Fouling of the in-stack cooling circuit is a named failure mechanism

Inspection checklist

Serial number and generation — a Gen 2 unit is 440 kW at about 41% LHV while the current build is 460 kW at 43.5-44.4% Cell stack install date and hours — the platform carries a 10-year cell stack life and only the maker supplies replacements Power fade — the maker publishes 460 kW at year 1 falling to 420 kW at year 10, an 8.7% loss over the stack life Field utilization — one Korean operator reported utilization falling from 91.9% in year 1 to 76.5% by year 4 Acid inventory — phosphoric acid evaporates from the matrix and leaves in the exhaust; DOE measured it after 43,000 hours of operation Steady-state decay — platinum sintering and carbon support corrosion, modelled against field data out to 60,000 hours Start-stop decay — carbon and catalyst corrosion occur on both shutdown and startup, a mechanism distinct from steady-state decay Ammonia scrubber — required where natural gas nitrogen content exceeds 1% by volume, because ammonia can cause outright failure Reformer and desulfurizer — the fuel processing system is roughly 20% of system cost, carries its own overhaul, and is absent on hydrogen builds Cooler circuit — cooler plugging is 1 of the 6 failure mechanisms named in the DOE teardown work Cooling module — the unit ships with a separate 3,190 lb cooling module that a listing may omit Certification vintage — inverter listings run UL 1741-2010, then UL 1741 SA, then UL 1741 SB with IEEE 1547 Service transferability — no third-party re-stacker exists, so a non-transferable agreement removes 100% of serviceability Quality programme scope — confirm whether the unit falls inside the maker's Group B or Group C stack programme for units installed 2020 to 2022 Rigging — the natural gas power module runs 57,000 to 60,000 lb against 49,428 lb for the hydrogen build

Regional notes

Hydrogen at scale on this platform is a Korean phenomenon rather than a North American one, anchored by a 40 MW long-term service agreement with UH Power running to 2046 at 72.93 million USD. Any US installation adds an NFPA 2 hydrogen storage and piping scope.