PEM Water Electrolysis Patent Landscape 2026
PEM water electrolysis is a concentrated growth-stage field, with Hoeller Electrolyzer GmbH commanding a dominant share of the top-100 filers’ combined patent records. The field is expanding on a multi-year basis, though annual volume has eased from its 2018 peak and recent years remain understated by publication lag.
A heavily concentrated field led by a single specialist
Hoeller Electrolyzer GmbH sits at the top of the applicant ranking with 34 patent records, well ahead of Hydrogenics Corp at 13 and ACS Ind Inc at 7. The top five filers account for 49% of the hundred largest filers’ combined total, signalling high concentration in a field with 101 patent families in scope.
A clear two-tier structure exists: one dominant specialist, one established incumbent, and a cluster of mid-tier players each holding single-digit counts. The gap between the leader and the second-ranked applicant is more than 2.5-fold, indicating that Hoeller Electrolyzer GmbH has pursued an unusually focused filing strategy relative to peers.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Hoeller Electrolyzer GmbH | 34 | |
| 2 | Hydrogenics Corp | 13 | |
| 3 | ACS Ind Inc | 7 | |
| 4 | GM Global Technology Operations LLC | 6 | |
| 5 | Ohmium International Inc | 5 | |
| 6 | Netherlands Organisation for Applied Scientific Research (TNO) | 5 | |
| 7 | Korea Institute of Energy Research | 3 | |
| 8 | Fraunhofer Society for the Advancement of Applied Research | 3 | |
| 9 | IGAS Energy GmbH | 3 | |
| 10 | SIEMENS ENERGY GLOBAL GMBH & CO KG | 2 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | University of Southern Denmark | 2 | |
| 12 | M S Sentient Engines Pte Ltd | 2 | |
| 13 | Guangzhou Xuheng Technology Co Ltd | 2 | |
| 14 | Guangdong Kavorlo Hydrogen Technology Co Ltd | 2 | |
| 15 | IRD Fuel Cells | 2 | |
| 16 | The Lubrizol Corporation | 2 | |
| 17 | Siemens AG | 2 | |
| 18 | Beijing Yihuatong Hydrogen Energy Technology Co Ltd | 2 | |
| 19 | UChicago Argonne LLC | 2 | |
| 20 | Baowu Clean Energy Co Ltd | 1 |
The leader’s concentration in C25B electrolytic-production subclasses signals deep coverage of core cell and stack architectures. Challengers such as Hydrogenics Corp broaden into H01M fuel-cell overlaps, suggesting differentiated but narrower claim scope relative to the front-runner.
Filings from approximately 2024–2026 are likely under-counted due to patent publication lag; trend readings for those years should be treated as lower-bound estimates. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Multi-year growth with a dominant electrolytic-production core
The annual filing trend and IPC composition together reveal a field that has grown substantially over the multi-year window while remaining technically anchored in electrolytic-production chemistry. Adjacent branches appear in modest counts, pointing to selective diversification rather than broad sprawl.
Annual filing trend
Filings rose from 12 in 2017 to a peak of 20 in 2018, then fell sharply before recovering through 2021 and stabilising at 12–15 per year from 2023 onward. The recent three-year window sits 57% above the prior three-year window on a multi-year basis. Figures for 2024–2026 are understated by publication lag and should not be read as a decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
C25B (electrolytic production of compounds) dominates with 127 patent records, dwarfing all adjacent branches. H01M (batteries, cells and fuel cells) is the second branch at 16 records, followed by C02F (water and wastewater treatment) at 8 and several manufacturing and materials branches—B22F, C23C, F17C—each at 5 records. The long tail of low-count branches reflects opportunistic cross-domain filings rather than sustained parallel programmes.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Water electrolysis stack for generating hydrogen a…
A water electrolysis stack for producing hydrogen and oxygen from water has a number of PEM electrolysis cells, arranged to form a cell stack. The cell stack is penetrated by a first channel for supplying water, a second channel for removing water and the product gas oxygen and a third channel for removing gas hydrogen. The electrolysis cells have a… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Porous electrolyzer gas diffusion layer and method… | 24 |
| 2 | 混合电解水制氢系统及混合电解水制氢系统的控制方法 | 21 |
| 3 | Method of operating a water electrolysis apparatus… | 19 |
| 4 | Storing and restoring the electrical energy e.g. w… | 19 |
| 5 | System and sub-systems for production and use of h… | 17 |
| 6 | Bipolar plate for a PEM electrolyzer | 13 |
| 7 | Method for operating a water electrolysis device | 12 |
| 8 | 一种板框式可叠加的水电解制氢PEM电解装置 | 11 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the patent structure means for R&D investment
The combination of high concentration, a growth lifecycle, an absence of recorded co-filing partnerships, and broad geographic coverage shapes both the competitive risk and the entry calculus for new participants.
Growth stage with easing annual volume
The field is classified as Growth: the recent three-year filing window is 57% above the prior three-year window, confirming multi-year expansion. Annual volume peaked in 2018 and has since stabilised rather than continued climbing, suggesting the initial surge of foundational filings has passed. Entrants should expect strong prior-art density in core cell and membrane electrode assembly architectures.
Growth · eased from 2018 peakOne dominant specialist, a thin second tier
The top five filers hold 49% of the hundred largest filers’ combined records, with the leader alone accounting for 34 patent records—more than twice the second-ranked Hydrogenics Corp at 13. This steep drop-off means the field has one clear anchor and a fragmented mid-tier, reducing the risk of a coordinated blocking coalition but increasing exposure to the leader’s portfolio in core stack and bipolar-plate claims.
High concentrationNo recorded co-applicant activity in this corpus
The collaboration evidence is currently pending for this dataset: no co-applicant filings are recorded in the evidence. This absence may reflect the proprietary nature of PEM stack IP or the small corpus size rather than a structural absence of partnerships in the broader industry. R&D teams should verify co-filing patterns in a wider search before concluding the ecosystem is closed.
Evidence pendingChina leads filings; US and PCT routes also significant
China is the leading filing jurisdiction with 31 patent records, followed by the United States at 27 and WIPO PCT at 17. Europe (EPO) accounts for 14 records, while Australia and India each reach 9—an unusually broad emerging-market footprint for a specialist hardware technology. The wide jurisdictional spread indicates that leading applicants are pursuing international protection rather than confining rights to home markets.
China-led, broadly internationalGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
Co-filing pairs, ranked by the number of jointly-filed patent families.
Hoeller Electrolyzer GmbH leads; challengers focus on system and fuel-cell overlaps
Two applicants stand apart from the mid-tier field. Hoeller Electrolyzer GmbH holds a commanding position in core electrolytic-production subclasses, while Hydrogenics Corp pursues a broader technology footprint that spans fuel-cell architectures.
Hoeller Electrolyzer GmbH
Hoeller Electrolyzer GmbH holds 34 patent records, the largest share of any single applicant. Its filings are tightly concentrated in C25B 15 (process control), C25B 9 (cell and stack design), and C25B 1 (hydrogen production), covering the full electrolyzer stack from chemistry to system operation. Momentum data classifies the company as a new entrant in the recent window, suggesting its large portfolio was built rapidly and may still be expanding.
patent records: 34Hydrogenics Corp
Hydrogenics Corp holds 13 patent records and differentiates through a broader technology mix: its primary focus areas span C25B 9 (stack design), H01M 8 (fuel-cell systems), and C25B 13 (membrane and electrode components). This overlap with fuel-cell IP suggests Hydrogenics is positioning its PEM electrolysis assets within an integrated hydrogen generation and conversion strategy. No momentum data classifies it as a new entrant, indicating a more established but slower-growing presence.
patent records: 13| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Hoeller Electrolyzer GmbH | 1 | ▲ new entrant |
| ACS Ind Inc | 4 | ▲ new entrant |
| GM Global Technology Operations LLC | 2 | ▲ new entrant |
| Netherlands Organisation for Applied Scientific Research (TNO) | 1 | ▲ new entrant |
| Ohmium International Inc | 1 | ▲ new entrant |
| IGAS Energy GmbH | 3 | ▲ new entrant |
Under-served adjacent branches worth watching
Several IPC branches appear at low counts relative to the dominant C25B core, suggesting areas where the existing patent landscape is thin. These observations reflect relative sparsity; whether each represents a genuine entry opportunity depends on technical relevance and commercial pathway.
B22F · Powder metallurgy for catalyst and diffusion layer fabrication
B22F (powder metallurgy) appears at only 5 patent records—3% of branch-level counts—despite its direct relevance to manufacturing PEM catalyst layers and porous transport layers via sintering and additive powder processes. Ohmium International Inc is the primary filer in this branch, concentrating on B22F 3 sintering. The thin coverage and clear manufacturing application suggest room for new entrants with advanced powder-processing know-how, particularly for platinum-group-metal catalyst deposition at reduced loading.
Search this in Eureka →C23C · Coating and surface deposition for membrane and bipolar plate protection
C23C (coating and surface deposition) holds 5 patent records, again representing a sparse 3% of branch-level counts. The Netherlands Organisation for Applied Scientific Research (TNO) is the most active filer here, focused on C23C 16 chemical vapour deposition. Coating technologies for corrosion-resistant bipolar plates and ionomer-electrode interfaces are critical to stack longevity, yet the branch remains lightly covered. An entrant with physical or chemical vapour deposition expertise aligned to PEM-compatible substrates could address a technically validated gap.
Search this in Eureka →How leading applicants differ across technology routes
Route coverage across the main technology branches in the current evidence set.
| Player | C25B 9 · Electrolytic production of compounds | C25B 1 · Electrolytic production of compounds | C25B 15 · Electrolytic production of compounds | C25B 11 · Electrolytic production of compounds | C25B 13 · Electrolytic production of compounds |
|---|---|---|---|---|---|
| Hoeller Electrolyzer GmbH | Strong · 32 | Strong · 29 | Strong · 33 | Absent | Emerging · 5 |
| Hydrogenics Corp | Strong · 12 | Moderate · 5 | Absent | Absent | Moderate · 6 |
| GM Global Technology Operations LLC | Strong · 6 | Strong · 4 | Moderate · 3 | Moderate · 2 | Absent |
| ACS Ind Inc | Strong · 7 | Absent | Absent | Moderate · 3 | Strong · 4 |
| Ohmium International Inc | Strong · 5 | Strong · 5 | Absent | Strong · 4 | Absent |
| Korea Institute of Energy Research | Strong · 3 | Strong · 3 | Absent | Strong · 3 | Absent |
| Netherlands Organisation for Applied Scientific Research (TNO) | Absent | Absent | Absent | Strong · 5 | Strong · 3 |
Frequently asked questions
The corpus contains 101 patent families in scope, spanning global filings across more than a decade. Patent-record counts across jurisdictions and IPC branches exceed this figure because a single family can be filed in multiple offices and classified under multiple technology codes.
Hoeller Electrolyzer GmbH leads with 34 patent records, more than double the second-ranked Hydrogenics Corp at 13 patent records. Both are classified as active filers in the most recent window.
The field is in a Growth stage. The recent three-year filing window is 57% above the prior three-year window on a multi-year basis. Annual volume peaked in 2018 and has since stabilised rather than continued climbing. Figures for 2024–2026 are understated by publication lag and should not be interpreted as a real-terms decline.
China leads with 31 patent records, followed by the United States at 27, WIPO PCT at 17, and Europe (EPO) at 14. Australia and India each account for 9 records, indicating unusually broad international protection strategies among leading applicants.
The most-cited works in the corpus include a patent on porous electrolyzer gas diffusion layers (24 citations), a Chinese-language filing on hybrid water electrolysis hydrogen production systems (21 citations), and two patents on methods of operating water electrolysis apparatus (19 citations each). A dedicated bipolar plate design for PEM electrolyzers has also attracted 13 citations.
B22F (powder metallurgy), C23C (coating and surface deposition), and F17C (pressure vessels and gas storage) each appear at only 5 patent records in the corpus. C02F (water and wastewater treatment) holds 8 records. These branches are adjacent to core PEM stack manufacturing and system integration but remain sparsely covered relative to the dominant C25B class.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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