On-demand, high-purity hydrogen from PEM electrolyzers for single-cell characterization, stack durability cycling, and MEA development. Load-following generators match variable demand profiles automatically — no cylinders, no supply interruptions, no safety compromises.
Fuel cell test stands require a reliable, variable-flow hydrogen supply that can follow dynamic load profiles, plus nitrogen for purging and startup/shutdown sequences, and deionized water for humidification and cooling.
High-purity hydrogen feeds the fuel cell anode where it is oxidized to protons and electrons, generating electrical current. The generator must follow variable demand as the test stand cycles through different load conditions and polarization curves.
Nitrogen purges the fuel cell and gas lines during startup, shutdown, and emergency stop sequences. It displaces hydrogen to prevent flammable mixtures and conditions the MEA before and after testing. Also used for leak testing new assemblies.
Fuel cell test stands use deionized water for reactant gas humidification, coolant loops, and MEA conditioning. Water with ionic impurities contaminates the membrane and accelerates degradation during long-term durability testing.
Fuel cell testing is inherently dynamic. A typical test protocol cycles through OCV, polarization curves, impedance spectroscopy, and accelerated stress tests — each requiring different hydrogen flow rates. PEM electrolysis generators automatically adjust production to match real-time demand, storing excess in an internal buffer tank during low-demand phases and releasing it during peaks.
The cylinder problem for fuel cell labs: A single-cell test fixture running at 1 A/cm² on a 25 cm² MEA consumes approximately 175 mL/min of hydrogen. A short stack of 10 cells at the same current density requires 1.75 L/min. Scale to a full stack of 100+ cells and you need 15–20+ L/min — depleting a standard hydrogen cylinder in under 6 hours.
For durability testing protocols that run 1,000–5,000+ hours continuously, cylinder logistics become untenable. An on-site generator runs unattended 24/7, eliminating supply interruptions that would invalidate months of accelerated aging data.
Purity matters: Even parts-per-million levels of CO, NH₃, or H₂S in the hydrogen feed can poison the platinum catalyst on the fuel cell MEA, causing irreversible performance degradation. PEM electrolysis produces hydrogen from water with no carbon-containing feedstock — eliminating CO contamination at the source. This is inherently cleaner than steam methane reforming (SMR) hydrogen that may contain trace CO even after purification.
The LNI Swissgas HG Series covers single-cell R&D (100–600 cc/min) through full-stack validation (up to 20 SLPM with HG PRO M). For pre-production and manufacturing-scale testing, Nel Hydrogen S and H Series electrolyzers deliver 10–228 SCF/h at up to 218 psig. We supply hydrogen generation from bench to production line.
Startup sequence: Before introducing hydrogen, the entire fuel cell and gas delivery system must be purged with nitrogen to displace air. Hydrogen mixed with air at 4–75% concentration is flammable. A thorough nitrogen purge ensures the system is inert before hydrogen flow begins.
Shutdown sequence: After testing, nitrogen purges hydrogen from the anode side, gas lines, and any dead volumes. This prevents hydrogen accumulation in enclosed spaces and ensures the system is safe for maintenance, cell disassembly, or unattended storage.
Emergency stop (E-stop): In fault conditions, the test stand controller triggers an immediate nitrogen purge to displace hydrogen from the system. This requires nitrogen to be available instantly and continuously — a requirement that on-site generation meets more reliably than cylinder supply with manual switchover.
Leak testing: New stack assemblies, gaskets, and fittings are pressure-tested with nitrogen before hydrogen is introduced. Nitrogen is safe to use at elevated pressures without the explosion risk of hydrogen leak testing.
MEA conditioning: Some break-in protocols use nitrogen purge cycles with controlled humidity to condition the membrane before performance characterization begins.
Reactant humidification: PEM fuel cells require humidified hydrogen and air feeds to maintain membrane hydration. The humidifier uses deionized water to prevent mineral deposits in the bubbler or injector that would degrade humidification performance over time.
Coolant loop: Multi-cell stacks generate significant heat that must be removed via a coolant loop. DI water (or DI water/glycol mixture) is used as coolant to prevent galvanic corrosion and mineral scaling in the bipolar plate cooling channels.
Hydrogen generator feed: PEM electrolysis hydrogen generators consume deionized water as their feedstock — splitting H₂O into H₂ and O₂. The HLP Series water purifier supplies both your hydrogen generator and your test stand humidifier/coolant from a single unit.
An HLP 10p or 20p deionizer supplies feed water for your HG PRO hydrogen generator, humidification water for your test stand, and coolant water for your stack — all from one compact unit connected to your building’s tap water supply.
Quick reference for hydrogen, nitrogen, and water requirements by test scale.
| Test Configuration | H₂ Flow | H₂ Pressure | N₂ Purge | Water | Recommended System |
|---|---|---|---|---|---|
| Single cell (5–50 cm²) R&D | 50–500 cc/min | 1–3 bar | 1–5 L/min | Type II | HG PRO + NG EOLO + HLP 5p |
| Short stack (5–20 cells) | 0.5–5 SLPM | 1–5 bar | 5–15 L/min | Type II | HG PRO 1500 + NG SIRIO + HLP 10p |
| Full stack (50–200 cells) | 5–20 SLPM | 3–12 bar | 10–30 L/min | Type II | HG PRO M + NG CASTORE XS + HLP 20p |
| Multi-stand lab (2–4 stands) | 10–40+ SLPM | 3–12 bar | 20–60 L/min | Type II | HG PRO M 20M + NG CASTORE XL + HLP 20p |
| Durability cycling (1,000+ h) | Variable | Per protocol | Intermittent | Type II | HG PRO M + NG EOLO + HLP 10p |
| Production / QC testing | 20–200+ SLPM | Up to 30 bar | Central supply | Type II | Nel S/H Series + NG CASTORE PRO |
Fuel cell R&D labs and test facilities that switch from cylinder supply to on-site generation gain safety, reliability, and operational advantages that directly improve test quality.
A PEM generator stores less than 500 mL of hydrogen at any moment. A cylinder rack holds 50,000+ liters at 2,200+ psi. On-site generation eliminates the single largest safety risk in your test facility.
1,000–5,000 hour durability protocols cannot tolerate supply interruptions. An on-site generator runs 24/7 without cylinder changeouts that would invalidate months of test data.
PEM electrolysis produces hydrogen from water with no carbon feedstock. Zero CO contamination at the source — no risk of catalyst poisoning from trace carbon monoxide.
The generator automatically adjusts hydrogen production to match real-time test stand demand. No wasted gas during low-load phases, instant availability during peak demand.
No gas purchase orders, delivery fees, cylinder rental, or hazmat handling. Your hydrogen cost is just electricity and deionized water — predictable and dramatically lower than cylinders.
Start with an HG PRO for single-cell R&D, add an HG PRO M for stack testing, and scale to Nel electrolyzers for production. Same technology platform from bench to manufacturing floor.
Our hydrogen generators, nitrogen generators, and water purifiers support every fuel cell test stand and electrochemical characterization system.
G400/G500 series test stations. Single cell to multi-stack testing. Fully automated H₂/N₂ gas management with load-following support.
850e Multi-Range Fuel Cell Test System. 890e Advanced Fuel Cell Test Load. Single cell to short stack characterization.
Evaluator test benches. Single cell through multi-kW stack testing. Automated gas supply and humidification control.
Fuel cell test stations with integrated EIS. Multi-channel testing for high-throughput MEA screening and durability studies.
Potentiostats and impedance analyzers for half-cell and single-cell electrochemical characterization. Hydrogen feed for RDE and MEA testing.
Electronic loads and fuel cell test systems for production QC. High-throughput end-of-line testing with automated gas management.
University, national lab, and OEM-built test fixtures. Standard gas connections, adjustable pressure, and flow-following operation.
Central hydrogen and nitrogen supply for facilities running 4–20+ test stands. HG PRO M or Nel electrolyzers feed your entire test bay.
Tell us about your fuel cell test configuration — single cell or stack, number of test stands, peak hydrogen flow, and testing protocol. We will size the right combination of hydrogen generator, nitrogen supply, and water purification for your facility.