Use a technical supplier interview to close gaps in a PEM electrolyzer proposal. Ask for the operating condition, document and responsibility behind each important answer. A short, traceable response is more useful than a broad promise of customisation or high performance.
This guide follows the buyer’s initial OEM RFQ. It focuses on reviewing the supplier’s answer rather than repeating the RFQ input sheet.
Cover illustration: conceptual scene; configuration varies by project.
1. Establish what the quoted duty means
Ask which configuration delivers the proposed hydrogen output, at what gas reference conditions, outlet pressure and gas quality. Confirm whether the figure is nominal, maximum or demonstrated under a specific test. Request a product specification tied to the quotation revision.
For a stack, identify the conditions needed from the integrator. For a complete system, ask where the supplier’s performance responsibility ends and which external loads or utilities remain outside the package.
2. Use questions that lead to evidence
| Topic | Question to ask | Useful answer or record |
|---|---|---|
| Power boundary | Is the stated input stack DC or package AC, and what auxiliaries are included? | Electrical boundary and defined operating point |
| Gas quality | Where is gas sampled, which impurities are limited and how are they measured? | Gas specification and applicable test method |
| Water and cooling | What quality, flow, temperature and heat-removal requirements apply? | Model-specific utility schedule |
| Operating window | What load range, starts, standby states and limits are supported? | Approved operating envelope and restrictions |
| Gas-side interfaces | What pressure and differential-pressure limits apply to the supplied equipment? | Interface drawing and operating instructions |
| Controls | Which signals, interlocks, alarm states and data are available? | Interface list and control responsibility matrix |
| Verification | What will the proposed FAT prove and what remains for site acceptance? | Test plan, conditions and record format |
3. Separate confirmed answers from assumptions
For each reply, record the source document, revision, reviewer and open action. Classify it as confirmed, conditional, unavailable or requiring development. If a supplier says an option is possible, ask what review and validation remain before it can enter the accepted specification.
A video of equipment running can support a discussion, but it does not replace the defined measurements needed to demonstrate your acceptance criteria. Request evidence appropriate to the actual claim.
4. Review changes and responsibility boundaries
Ask which changes to utilities, gas treatment, software or downstream equipment would require a new review. Confirm who approves design changes and how updated instructions and drawings will be delivered.
Use the stack interface checklist for detailed integration responsibility. Use the customisation status matrix when options are not yet defined.
5. Close essential questions before commercial release
Assign an owner and deadline to every unresolved requirement. Incorporate agreed answers and deviations into the purchase specification. Avoid treating meeting notes, marketing pages and an unqualified quotation as interchangeable technical approvals.
Review the technical resources page and ask which additional documents are available for the proposed model and purchase stage.
Discuss the open technical questions in your project
Send the proposed duty, stack or system boundary, utilities, interfaces and a numbered list of open questions. Include the required acceptance evidence and the configuration you are considering.
Published by Hele Titanium Hydrogen. Updated 17 October 2026. Operating limits, interface options and test scope must be agreed for the selected equipment.
