Green-hydrogen coverage focuses on electrolysers, offtake and molecules — and almost never on the electrical plant that makes them run. Yet an electrolyser is, electrically, one of the most demanding loads on any grid: a large DC consumer fed through dedicated rectifier transformers, connected via its own grid-connection substation, often co-located with gigawatts of new wind and solar that need their own step-up transformers. Every hydrogen FID is a transformer procurement event.
Where the transformers are in a hydrogen plant
- Rectifier transformers — each ~100 MW electrolyser block typically takes multiple rectifier-transformer units feeding thyristor or IGBT rectifiers. Rectifier duty means high harmonic content, high load factors and frequent thermal cycling.
- Grid-connection substation — GW-scale projects connect at EHV (380/400 kV in the Gulf), requiring power transformers, GIS and full substation scope.
- Renewables step-up — dedicated wind/solar capacity (e.g. 4 GW at NEOM) brings hundreds of pad-mount and collector-substation transformers.
- Insulation systems — harmonic heating pushes rectifier-transformer designs toward upgraded thermal classes: aramid and aramid-hybrid insulation rather than standard kraft/pressboard — a materially different bill of materials from a grid transformer.
Rule of thumb: 1 GW of electrolysis ≈ 1.2–1.4 GVA of installed transformer capacity across rectifier units, the grid connection and auxiliaries — before counting the dedicated renewables plant behind it.
Major green-hydrogen projects — status tracker
Tracked from public announcements and updated as projects reach FID, construction and commissioning. Sourced from the same census behind our Grids page.
| Project | Location | Electrolyser | Output | Status | Note |
|---|
What to watch
- Oman's land blocks — Hydrom has awarded eight blocks around Duqm and Dhofar; each FID (Hyport Duqm expected 2026–27) triggers rectifier-transformer and substation tenders.
- NEOM ramp-up — the 2.2 GW NGHC plant powers up through 2026; follow-on Saudi hydrogen sites would repeat its transformer scope.
- India's National Green Hydrogen Mission — SECI auctions plus the Kandla and Mundra hubs put India on track to be the largest builder of electrolyser grid connections after China.
- Europe's core-network plants — German projects like RWE's GET H2 Nukleus connect electrolysis directly to the national hydrogen core network, with grid reinforcement on the electricity side.
Contract awards and tenders from these projects appear in our Daily Intel as they happen.