Electrolysers: Value chain

Huge factories, tiny orders: the hydrogen overcapacity puzzle

What this tab covers Who does what, from equipment makers to builders, owners, operators, traders and users, with the leading companies at each step.

Metals and polymers become electrodes, membranes and separators. These go into stacks, the stacks into systems with rectifiers and gas treatment, and the systems into plants built by contractors for refineries, chemical makers and green-fuel developers. In water electrolysis the factories are far ahead of orders. Chlor-alkali and aluminium are mature, century-old industries.

The chain

Critical materials Water-electrolyser makers Projects and contractors Owners and users Chlor-alkali technology Aluminium smelting

Stage	What happens	Leading companies
Critical materials	Nickel for alkaline electrodes, platinum and iridium catalysts, titanium plates and porous layers, PFSA membranes. Iridium and titanium are the highest supply risks for the US.	Chemours (United States)⁶⁸²⁰
Water-electrolyser makers	End-2025 factory capacity was nearly 58 GW a year but output under 5 GW (about 9% use); China has 60% of capacity, Europe 20%, the US 10%. BloombergNEF ranked thyssenkrupp nucera first by 2024 deliveries, with six Chinese firms in the top ten. Elogen (France) halted its gigafactory and turned to research in 2025-26.	thyssenkrupp nucera (Germany) LONGi Hydrogen (China) Peric (China) Sungrow Hydrogen (China) Envision (China) Nel (Norway) Siemens Energy (Germany) ITM Power (United Kingdom) Sunfire (Germany) John Cockerill (Belgium) Plug Power (United States)³⁶²¹²²²³²⁴²⁵²⁶²⁷
Projects and contractors	Large alkaline plants are built from standard 20 MW modules: NEOM (2.2 GW, Saudi Arabia), Stegra (740 MW, Sweden) and Envision's 500 MW Chifeng plant (China, 2025).	thyssenkrupp nucera (Germany) Envision (China)⁹²¹
Owners and users	Installed water-electrolysis capacity doubled in 2025 to more than 4 GW, mostly feeding refining, ammonia and methanol.	⁴
Chlor-alkali technology	thyssenkrupp nucera claims about 50% of the chlor-alkali electrolysis market, with over 600 projects; Industrie De Nora (electrodes) owns 25.85% of it. Euro Chlor members have 11 Mt a year of chlorine capacity at 60 sites.	thyssenkrupp nucera (Germany) Industrie De Nora (Italy)⁹¹⁵
Aluminium smelting	Smelters own the pot lines; cell designs are licensed by a few developers. EGA has licensed its DX technology for over 0.5 Mt of capacity outside the UAE; Rio Tinto offers AP cells; China's GAMI and SAMI design the 400-600 kA cells used in China.	Chalco/Chinalco (China) China Hongqiao (China) Rusal (Russia) Rio Tinto (Australia/United Kingdom) EGA (United Arab Emirates) Alcoa (United States)¹⁶¹⁷²⁸²⁹³⁰

Sources

Green H2 electrolyser sector enters consolidation: IEA (reporting IEA Global Hydrogen Review 2026; cost figures not on the IEA's free web pages) Argus Media, 2026
Global Hydrogen Review 2026: Production International Energy Agency, 2026
Water Electrolyzers and Fuel Cells Supply Chain: Supply Chain Deep Dive Assessment US Department of Energy, 2022
Critical Iridium Demands arising from future Expansion of Proton Exchange Membrane Electrolysis (Wortmann, Stolten, Heinrichs), preprint arXiv 2509.05357, 2025
thyssenkrupp nucera General Investor Presentation, May 2026 (company claims) thyssenkrupp nucera, 2026
Our industry: chlorine production and capacity Euro Chlor, 2026
AP60 and APXe smelting technology factsheet (company data) Rio Tinto AP Technology, 2015
History and Recent Developments in Aluminum Smelting in China (Gao, Wang, Shi, Hu), 35th ICSOBA Conference ICSOBA, 2017
Electrolyzer Supply Chain Readiness Level (SCRL), 2024 Annual Merit Review poster NREL / Argonne National Laboratory for US DOE, 2024
The IEA's Global Hydrogen Review 2025: green hydrogen ramp up is slower than we wanted, but it is happening all the same Green Hydrogen Organisation (GH2), 2025
BNEF reveals top ten hydrogen electrolyser makers in the world by deliveries in 2024: six are Chinese Hydrogen Insight (reporting BloombergNEF), 2025
SMM Survey: Hydrogen Energy Weekly Electrolyzer Industry Review, 16-22 January 2026 Shanghai Metals Market (SMM), 2026
China unveils higher-capacity H2 alkaline electrolyser (Peric) Argus Media, 2022
Sunfire 2025: scaling, partnerships and European strength (company news) Sunfire, 2025
John Cockerill finishes 5MW electrolyser using McPhy-acquired assets gasworld, 2026
GTT's electrolyser revenues shrink to EUR 0.1m after Elogen's R&D pivot gasworld, 2026
Global giants: unveiling the top 5 primary aluminium manufacturers in 2023 AL Circle, 2024
EGA's technology Emirates Global Aluminium (company claims), 2026
Alcoa Corp Form 10-K for fiscal year 2025 Alcoa / US SEC, 2026