Solid-State Transformer for Green Hydrogen Patent Landscape
Solid-State Transformer for Green Hydrogen Patent Landscape in 2026
Patenting at the intersection of solid-state transformers and green hydrogen is nascent: only 8 patent families are on record, all filed from 2022 onward, with Hitachi Energy Ltd holding the largest individual position. The field is highly concentrated among a handful of entrants, leaving substantial room for new technical contributions across power conversion, electrolysis integration, and related application domains.
Hitachi Energy leads a heavily concentrated, early-stage field
With only 8 patent families in scope, solid-state transformers applied to green hydrogen production constitute one of the smallest and earliest-stage technology clusters in the power-to-hydrogen space. Hitachi Energy Ltd holds the top position with 3 patent families, followed by Huawei Digital Power Technologies Co., Ltd. with 2 families, and Georgia Tech Research Corporation and individual inventor Francisco Daniel Freijedo Fernandez each with 1 family.
The top five filers account for 100% of the hundred largest filers’ combined total in this corpus, reflecting extreme concentration in an emergent niche where institutional incumbents and a research university represent the entire organized filing base alongside one individual inventor.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Hitachi Energy Ltd | 3 | |
| 2 | Huawei Digital Power Technologies Co., Ltd. | 2 | |
| 3 | FREIJEDO FERNANDEZ FRANCISCO DANIEL | 1 | |
| 4 | Georgia Tech Research Corporation | 1 |
Hitachi Energy’s simultaneous coverage of electrolytic production (C25B), power supply and grid systems (H02J), and power conversion (H02M) signals an integrated systems-level approach, while Huawei Digital Power’s focus on grid systems and Georgia Tech’s focus on power conversion suggest more targeted technical positions. The individual inventor KIKKAWA YOSHITSUGI’s marine-vessel and acyclic-compound emphasis points to a distinct application vector.
Filing activity in 2024 and 2025 is subject to publication lag; apparent zeros in recent periods should not be read as a cessation of activity. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Activity emerged in 2022 and technology coverage centers on power systems and electrolysis
The annual filing trend and technology composition together reveal a field that did not exist before 2022 and whose technical core sits at the interface of power conversion hardware and electrochemical hydrogen production.
Annual filing trend
Zero filings were recorded in every year from 2017 through 2021; activity began in 2022 with 3 families, continued in 2023 with 2, and reached 3 again in 2024. The 2025 and 2026 counts should be read as incomplete given normal publication lag of 12–24 months, not as a sign of declining interest.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H02J (power supply and grid systems) is the dominant IPC branch with 7 patent records, reflecting the grid-interface role of solid-state transformers. C25B (electrolytic production of compounds, covering electrolyzer hardware) follows with 5 records, and H02M (power conversion, AC/DC) contributes 4. The secondary branches B63B (ships and marine vessels) and C07C (acyclic and carbocyclic compounds) each hold 2 records and trace to the marine-application patents of one inventor, indicating a distinct non-utility-grid application niche.
↗ 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.
Multimode control of HF link universal minimal con…
Embodiments of the present disclosure include universal minimal converter comprising power converter circuits and controllers that can perform optimized control of power converters to implement multimodal control schemes using pre-defined set of modes in the control cycles on a cycle-by-cycle basis. The topology of the exemplary system provides for an… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Multimode control of HF link universal minimal con… | 8 |
| 2 | Green Energy Transportation System and Energy Tran… | 2 |
| 3 | A smart load system and method for regulating powe… | 2 |
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 competitive structure means for R&D investment
The combination of a very small corpus, a single dominant filer, and near-zero prior-art density before 2022 creates both opportunity and interpretive caution for engineers entering this space.
Nascent field with no determinable life-cycle stage
All 8 patent families were filed between 2022 and 2024, making the dataset too new and too small to assign a standard technology life-cycle stage. The evidence does not yet support inference about growth, peak, or saturation phases. Engineers can treat this as a pre-formation stage where core claims are still being staked and freedom-to-operate is likely broad.
Pre-formationThree organizations hold the entire recognized filing base
Hitachi Energy Ltd, Huawei Digital Power Technologies Co., Ltd., and Georgia Tech Research Corporation together account for the dominant share of institutional filings. There is no discernible second tier of challengers; the gap between the leader (3 families) and all others is narrow in absolute terms but represents a significant proportional advantage in a corpus of only 8 families. A single well-scoped filing program by a new entrant could materially alter the concentration picture.
High concentrationOne co-filing relationship identified: Freijedo Fernandez and Huawei Digital Power
The evidence shows a single co-applicant relationship between individual inventor Francisco Daniel Freijedo Fernandez and Huawei Digital Power Technologies Co., Ltd., representing 1 co-filed family. This inventor-corporate pairing is consistent with an early-stage ecosystem where individual researchers bring specialized expertise into industrial R&D pipelines. No multi-party consortium activity or cross-institutional co-filing is evident at this stage.
Early ecosystemEurope, the United States, and PCT filings share the lead jurisdictions
European Patent Office filings and US filings each account for 3 patent records, with 2 additional PCT (WIPO) records providing broader international coverage. This distribution reflects applicant strategies oriented toward the two largest clean-energy policy markets and indicates that at least some filers are pursuing multi-jurisdiction protection from the outset, a signal of commercial intent despite the small overall corpus.
EPO / US / PCTGo 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.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| FREIJEDO FERNANDEZ FRANCISCO DANIEL | Huawei Digital Power Technologies Co., Ltd. | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Hitachi Energy and Huawei Digital Power are the principal institutional filers
Both leaders entered the field as new entrants with no prior filing history in this intersection topic, consistent with the 2022 emergence of the corpus. Their technology emphases differ meaningfully, suggesting parallel rather than overlapping R&D programs.
Hitachi Energy Ltd
Hitachi Energy Ltd holds 3 patent families — the largest position in the corpus — and entered as a new entrant with all recent filings in the current measurement window. Their technology emphasis spans electrolytic production of compounds (C25B 9), power supply and grid systems (H02J 3), and power conversion (H02M 3) simultaneously, reflecting an integrated electrolyzer-to-grid architecture strategy rather than a component-level focus.
families: 3Huawei Digital Power Technologies Co., Ltd.
Huawei Digital Power Technologies Co., Ltd. holds 2 patent families and also entered as a new entrant. Their filing focus concentrates on grid systems (H02J 3), indicating an emphasis on the power-delivery and grid-interface functions of the solid-state transformer rather than the electrolyzer hardware itself. One of their families was co-filed with inventor Francisco Daniel Freijedo Fernandez, suggesting an externally sourced technical contribution.
families: 2| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Hitachi Energy Ltd | 3 | ▲ new entrant |
| Huawei Digital Power Technologies Co., Ltd. | 2 | ▲ new entrant |
| Georgia Tech Research Corporation | 1 | ▲ new entrant |
| FREIJEDO FERNANDEZ FRANCISCO DANIEL | 1 | ▲ new entrant |
Under-served adjacent branches worth monitoring
With no formal white-space candidates returned by the evidence, the adjacent branches identified below are observations drawn from the technology composition data — specifically the lower-share IPC classes present in the corpus — rather than validated opportunity assessments.
Marine and offshore hydrogen applications (B63B)
B63B (ships and marine vessels) appears with 2 patent records in the corpus, all attributable to a single inventor with a marine-application focus. This suggests that solid-state transformer integration into shipboard or offshore hydrogen production systems is technically plausible and has been explored, yet remains essentially uncontested by the larger institutional filers. An entrant with expertise in marine power systems could find limited prior art to navigate. Entry would require demonstrating the technical feasibility of high-frequency isolated conversion in marine environments, which is an engineering challenge distinct from stationary grid applications.
Search this in Eureka →Electrochemical compound synthesis beyond hydrogen (C07C)
C07C (acyclic and carbocyclic compounds) holds 2 patent records, again linked to the same marine-application inventor. The presence of this class suggests that solid-state transformer-driven power delivery for synthetic fuel or chemical synthesis pathways — beyond pure hydrogen — has been touched upon but not systematically developed by the main institutional players. This is an observation of relative sparsity; whether it constitutes a viable entry path depends on whether an organization has both power-electronics and electrochemical process competencies, and on the regulatory pathway for power-to-X products in target markets.
Search this in Eureka →How leaders differ by technology route
Strength of each leader across the main technology routes.
| Player | H02J 3 · Power supply & grid systems | C25B 9 · Electrolytic production of compounds | H02M 3 · Power conversion (AC/DC etc.) | H02M 7 · Power conversion (AC/DC etc.) | B63B 17 · Ships & marine vessels |
|---|---|---|---|---|---|
| Hitachi Energy Ltd | Strong · 3 | Strong · 3 | Strong · 3 | Strong · 3 | Absent |
| Huawei Digital Power Technologies Co., Ltd. | Strong · 2 | Absent | Absent | Absent | Absent |
| Georgia Tech Research Corporation | Absent | Absent | Strong · 1 | Strong · 1 | Absent |
| FREIJEDO FERNANDEZ FRANCISCO DANIEL | Strong · 1 | Absent | Absent | Absent | Absent |
Frequently asked questions
The evidence shows 8 patent families in scope globally, all filed between 2022 and 2024. This is a very small corpus consistent with a nascent, emerging technology intersection.
Hitachi Energy Ltd holds the largest position with 3 patent families. Huawei Digital Power Technologies Co., Ltd. is second with 2 families. Georgia Tech Research Corporation and individual inventor Francisco Daniel Freijedo Fernandez each hold 1 family.
According to the filing trend data, no patent families were recorded in this intersection from 2017 through 2021. Activity began in 2022 with 3 families and has continued each year through 2024.
Europe (EPO) and the United States each account for 3 patent records, and WIPO (PCT) filings account for 2 records. This spread indicates that leading filers are seeking protection in the major clean-energy policy markets from the outset.
H02J (power supply and grid systems) is the most represented class with 7 patent records, followed by C25B (electrolytic production of compounds) with 5 records and H02M (power conversion) with 4 records. Secondary classes include B63B (marine vessels) and C07C (acyclic and carbocyclic compounds), each with 2 records.
One co-applicant relationship is recorded: Francisco Daniel Freijedo Fernandez and Huawei Digital Power Technologies Co., Ltd. co-filed 1 family. No broader multi-party consortia or cross-institutional co-filings are evident in the current evidence.
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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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