Compressed-Air Energy Storage Patents: Top Companies & Trends 2026
- No single owner dominates. the ranked leader holds 465 records and the top 5 combined account for just 6.0% of all 28,181 records in scope — this is a fragmented field, not a walled-off one.
- Filing has cooled from its 2019 peak. annual filings ran from 1,014 in 2019 to 656 in 2024, a -31% change over 2021-2024, though 2025-2026 figures are still incomplete due to publication lag.
- Classification spreads across mechanical and electrical domains. gas-turbine plants (F02C, 5.4%), hydraulic machines (F03B, 4.7%) and batteries (H01M, 4.6%) all carry meaningful shares of the 28,181 records, with no single class holding a majority.
Filing growth compares 2021 (948 records) with 2024 (656) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 28,181 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks 28,181 published records matching compressed-air and liquid-air energy storage terms combined with core storage and conversion concepts — storage pressure, charge/discharge cycling, energy conversion and storage capacity. The scope spans mechanical plant hardware (gas turbines, hydraulic machinery, internal-combustion systems) alongside grid and battery-adjacent electrical claims, reflecting how compressed-air storage sits at the junction of thermal power engineering and grid-scale energy storage.
Records filed from around 2024 onward are undercounted here because publication typically lags filing by roughly 18 months — a real feature of patent data, not a sign the field has gone quiet.
Filing trends and technology composition
Two views of the same 28,181 records: how filing activity has moved year over year, and how records distribute across International Patent Classification subclasses.
Filing trend, 2017-2026
Annual filings rose from 713 in 2017 to a peak of 1,014 in 2019, then eased to 656 by 2024 — a -31% change across 2021-2024. The final two years shown are partial counts, not a real decline, since publication lag has not yet caught up.
Technology composition by IPC subclass
Gas-turbine plants (F02C) and hydraulic machines (F03B) lead the subclass counts, with batteries (H01M), power/grid systems (H02J) and steam/thermal plants (F01K) close behind. Because records can carry multiple IPC codes, these shares are each measured against the full 28,181-record base and sum to more than 100%.
Shares are the percentage of the 28,181 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Compressed-Air & Liquid-Air Storage Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about compressed-air & liquid-air storage patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaA representative recent filing
Construction elements and maintenance methods for compressed air energy storage systems
Describes transitioning a hydrostatically compensated compressed air energy storage system between operating and dewatered maintenance states, using a gas compressor/expander subsystem to charge an accumulator to a target storage pressure while managing the air-water interface and compensation liquid flow.Filed by Hydrostor Inc., published 2025-05-13 as US12297056B2 — illustrates how hydrostatic compensation and maintenance-state transitions are now being claimed as discrete inventive steps, not just incidental plant operation.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20080029570A1 | Pneumatically powered surgical cutting and fastening instrument with improved volume storage | 2,838 |
| 2 | US7441684B2 | Pneumatically powered surgical cutting and fastening instrument with audible and visual feedback features | 2,763 |
| 3 | US20080029574A1 | Pneumatically powered surgical cutting and fastening instrument with actuator at distal end | 2,645 |
| 4 | US20080029575A1 | Surgical cutting and fastening instrument with distally mounted pneumatically powered rotary drive member | 2,626 |
| 5 | US20080029573A1 | Pneumatically powered surgical cutting and fastening instrument with replaceable power sources | 2,563 |
| 6 | US7431189B2 | Pneumatically powered surgical cutting and fastening instrument with mechanical linkage coupling end effector… | 2,392 |
| 7 | US7448525B2 | Pneumatically powered surgical cutting and fastening instrument with manually operated retraction apparatus | 2,354 |
| 8 | US7740159B2 | Pneumatically powered surgical cutting and fastening instrument with a variable control of the actuating rate… | 2,251 |
| 9 | US20130201316A1 | System and method for server based control | 1,727 |
| 10 | US8631987B2 | Pneumatically powered surgical cutting and fastening instrument with a variable control of the actuating rate… | 1,704 |
Citation counts reward older filings that have had more time to accumulate citations within this corpus — read them as a signal of past influence, not current relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns worth acting on rather than just noting.
No single owner controls the field
The leading assignee holds 465 records against a total of 28,181, and the top 5 combined reach only 6.0% of all records in scope. That leaves a long tail of single- and few-filing entrants, which means freedom-to-operate analysis has to look well past the household names.
Activity has eased from its 2019 peak, not collapsed
Filings peaked at 1,014 in 2019 and had fallen to 656 by 2024, a -31% change across that span. Because publication lags filing by about 18 months, the 2025-2026 counts shown in the trend chart will fill in further and should not yet be read as continued decline.
Mechanical plant classes still outweigh battery-adjacent ones
F02C gas-turbine plants (5.4% of 28,181 records) and F03B hydraulic machines (4.7%) each carry a larger share than H01M batteries (4.6%), underscoring that compressed-air storage claims are still anchored in conventional power-plant engineering as much as in electrochemical storage.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to compressed-air & liquid-air storage patent landscape, with the prior art for and against each one.
Who is filing, and where momentum sits
The assignee ranking spans 100 companies pulled from the same 28,181-record base, from diversified industrials to narrower storage specialists.
A diversified filer sits at the top
The ranked leader holds 465 records, well ahead of fifth place at 259 and tenth place at 144 — a steep early drop-off that flattens quickly across the rest of the ranking.
Recent-year filing has slowed across most tracked assignees
Every assignee with recent-year momentum data in this set shows a year-over-year decline, ranging from a -54% drop to filers reporting zero filings in the latest year. This is consistent with the broader 2021-2024 easing rather than any single company's retreat.
Co-filing is limited and concentrated in a few relationships
Only 10 co-assignee pairs appear in the dataset, with the strongest pairing linked by 9 shared records. Most assignees in this field file independently rather than through joint ownership structures.
| Assignee | Recent year | YoY |
|---|---|---|
| Lone Gull Holdings Ltd | 6 | -54% |
| General Electric Co | 2 | -71% |
| Strong Force IoT Portfolio 2016 LLC | 1 | -67% |
| Silverbrook Research Pty Ltd | 0 | — |
| Johnson Matthey PLC | 0 | -100% |
| Strong Force VCN Portfolio 2019 LLC | 0 | -100% |
| Canon Inc. | 0 | -100% |
| Ford Global Technologies LLC | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, whitespace mapping or competitive tracking.
Map claims against the long tail
With the top 5 assignees holding just 6.0% of records, most of the field sits with smaller filers. A freedom-to-operate check needs to look past the familiar names into that long tail.
Explore the assignee rankingWatch the 2025-2026 fill-in
Current filing counts for the most recent years will rise as publication catches up. Re-checking the trend in a future cut will give a truer read on whether 2024's pace held or moved.
Track filing trends over timeProbe the under-claimed branches
Liquid-air phase-change cycles and hybrid CAES-battery control show thinner claim density than the core mechanical classes. That is where a well-drafted first claim has room to stand.
Search white space in EurekaCommon questions about compressed-air storage patents
The ranked leader in this dataset holds 465 records out of 28,181 in scope, with the field otherwise spread thinly across a ranking of 100 companies. The top 5 assignees combined account for only 6.0% of all records, so no single company controls the space. This means competitive tracking has to extend well beyond the largest filers to get a full picture of who is active.
Filing peaked in 2019 at 1,014 records and had eased to 656 by 2024, a -31% change over that three-year span. Because patent publication typically lags filing by around 18 months, the lower counts shown for 2025 and 2026 are incomplete rather than evidence of a further drop. Read the trend through 2024 as the most reliable recent signal.
Gas-turbine plant engineering (IPC class F02C) covers 5.4% of the 28,181 records, followed by hydraulic machines (F03B) at 4.7% and batteries and cells (H01M) at 4.6%. Power and grid systems (H02J) and steam/thermal plants (F01K) each sit around 4.1%. Because a single record can carry multiple classification codes, these figures do not sum to a clean 100% and should be read as independent shares of the whole corpus.
US12297056B2, published 2025-05-13, claims a method for transitioning a hydrostatically compensated compressed air energy storage system between a fully charged operating state and a dewatered maintenance state. It specifically covers charging an accumulator to a target storage pressure using a gas compressor/expander subsystem while managing the air-water interface and compensation liquid flow into a reservoir. Anyone designing maintenance procedures for liquid-compensated CAES accumulators should review this claim scope closely before finalizing a similar approach.
Branches such as liquid-air phase-change storage cycles, hybrid CAES-battery control systems, and thermal energy recovery from compression heat show comparatively thin claim density relative to the core gas-turbine and hydraulic machinery classes. These areas sit adjacent to well-covered mechanical plant engineering but have not attracted the same concentration of filings. A first claim drafted around a specific control method or thermal-recovery configuration in one of these branches would face less crowded prior art than a claim in the core F02C or F03B classes.
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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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.