Best Energy Companies in Japan
The 353 best Energy companies in Japan in 2026, ranked by funding and momentum. Funding, investors, founders, valuation, tech stack and live signals. Top: Shizen Energy.
Japan's Energy sector is more crowded and better-funded than most outsiders assume, and this directory ranks 353 companies across it by disclosed equity funding and recent momentum. Total disclosed capital sits at $1.1B, with Kyoto Fusioneering leading the pack at $110M, well ahead of Sharing Energy at $27M and EX-Fusion at $21M. Fusion is clearly having a moment here. So is the broader app layer: median install growth across energy-related apps is running at roughly +28% YoY across 138 tracked titles, a signal that end-user engagement with solar generation, EV battery tech, and energy management tools is genuinely accelerating, not just talked about.
What you won't find yet is a unicorn. Zero. That gap between the capital flowing in and the valuations breaking out is the story I keep watching this quarter. Geopolitical pressure is adding urgency globally, with US energy export strategy shifting fast as supply chains reorganize around new risk. Meanwhile, water-based fuel research and alternative approaches are attracting serious attention beyond Japan's borders. Investors like Mitsubishi UFJ Capital and JAFCO Group are already positioned; the question is which of these 353 companies converts momentum into a valuation milestone first.
- International grid edge study reveals countries needs and readiness f
Our analysis of 441 Energy companies
$135.1b in tracked funding; 76% of the stack-profiled cohort runs cloud-native; funding activity peaked in 2025.
Ranked: Best Energy companies in Japan
| # | Company | Disclosed funding | Last round | Employees | Founded | Founder | Tech stack | Market signals (1y) | Patents & IP focus | Recent signals |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Shizen Energy Developer of solar & wind energy projects | $474M | 43 mo ago | 261 | 2011 | — | WordPressApple iCloud MailMySQL+12 | 3 signals Contracts | — | 1 job opening · 2 awards |
| 2 | Toyo Engineering Corporation Provider of design, engineering and procurement services | $132M | 90 mo ago | 2,231 2,231 → 2,988 (+34%) | 1961 | Kiyoshi Nakao President & CEO | WordPressPleskMySQL+15 | 4 signals ▲33% Contracts | 514 patents Industrial chemical process equipment: distillation, urea synthesis, and compressed‑air storage systems. | 1 partnership · 1 expansion |
| 3 | Kyoto Fusioneering Provider of nuclear fusion reactor technology based on low-energy nuclear reaction technology | $110M | 9 mo ago | 90 | 2019 | Richard Pearson Co-Founder | WordPressMySQLPHP+17 | — | 16 patents High‑power gyrotron power supplies and fusion‑reactor blanket/isotope transport technologies | 1 job opening · 1 launch · 2 partnerships |
| 4 | Asuene Developer of solar energy projects | $69M | 24 mo ago | — | 2019 | Keihiro Iwata Co-Founder | — | — | 3 patents Software platforms for greenhouse gas emissions monitoring and management | — |
| 5 | Clean Energy Connect Limited information available | $30M | 12 mo ago | 2 | 2020 | — | WordPressMySQLPHP+20 | — | — | — |
| 6 | Sharing Energy Manufacturer of PV and energy storage system | $27M | 2 mo ago | 50 | 2018 | Kazuyuki Uemura CEO | WordPressMySQLPHP+14 | — | — | — |
| 7 | Looop Distributed solar power plant developer | $26M | 71 mo ago | 260 | 2011 | Soichro Nakamura Founder & CEO | microCMSApple iCloud MailGoogle Workspace+17 | — | — | — |
| 8 | Zephyr Manufacturer of wind turbines and developer of wind energy projects | $24M | 170 mo ago | 70 | 1997 | Masaya Kubo CEO | WordPressMySQLPHP+16 | — | 30 patents Control systems and hardware for wind turbine power generation and optimization | — |
| 9 | TRENDE Developer of renewable energy solutions and electricity trading platforms | $23M | 12 mo ago | 12 | 2017 | Ken Seno Co-Founder & Director | WordPressMySQLPHP+16 | — | — | — |
| 10 | EX-Fusion Manufacturer of nuclear fusion reactors | $21M | 8 mo ago | 9 | 2021 | Kazuki Matsuo CEO | WordPressMySQLPHP+13 | — | 24 patents Underwater navigation/lighthouse positioning systems and combustible oil production technologies. | — |
| 11 | UPDATER Supplier of electricity | $20M | 56 mo ago | 286 | 2011 | Tsukasa Oishi CEO | PHPDebianGSAP+23 | — | — | — |
| 12 | WASSHA Energy storage systems marketing and consulting services provider | $19M | 48 mo ago | 202 | 2013 | Satoshi Akita Founder & CEO | WordPressMySQLPHP+16 | — | — | 1 job opening |
| 13 | Sphelar Power Manufacturing and Designing of spherical shaped solar cells unlike flat panels | $18M | 169 mo ago | — | 2012 | Souichiro Imoto CEO & President | WordPressMySQLPHP+7 | — | 40 patents Integrated photovoltaic building components and semiconductor‑enhanced smart textiles. | — |
| 14 | enechain Provider of energy marketing services | $14M | 4 mo ago | 55 | 2019 | Ryo Nozawa Founder & CEO | STUDIOFirebaseNode.js+12 | — | — | 1 launch · 1 partnership |
| 15 | Aeterlink Supplier of electricity | $13M | 15 mo ago | 18 | 2020 | — | WordPressApple iCloud MailGoogle Workspace+18 | — | 87 patents Wireless power transfer systems and antenna/receiver technologies for efficient energy harvesting. | — |
| 16 | REXEV Manufacturer of batteries | $13M | 56 mo ago | — | 2019 | Takashi Fujii Co-Founder | WordPressMySQLPHP+20 | — | — | — |
| 17 | Monochrome Developer of integrated rooftop solar energy systems and home energy management systems. | $13M | 1 mo ago | — | 2021 | Yusuke Umeda CEO | SentryNode.jsTypeScript+18 | — | — | — |
| 18 | DG Capital Group Provider of digital grid solutions for supporting future power grids | $11M | 28 mo ago | — | 2020 | Rikiya Abe CEO & Director | NginxXserverGoogle Workspace | — | 4 patents Autonomous distributed control and interconnection for DC microgrid systems | — |
| 19 | Global Engineering Provider of integrated energy solutions and retail electricity services. | $10M | 76 mo ago | — | 1991 | Hirotada Takahashi CEO & President | Apache HTTP ServerMicrosoft 365jQuery UI+3 | — | 47 patents Wireless power delivery and condition monitoring for machine‑tool tooling and bearings | — |
| 20 | Challenergy Vertical axis wind turbine developer | $8M | 44 mo ago | 8 | 2014 | Atsushi Shimizu Founder & CEO | WordPressMySQLPHP+15 | — | 20 patents Magnus‑effect thrust generators for wind, hydro and tidal power conversion | — |
| 21 | ENECHANGE Provider of energy platform development and energy data analysis services | $8M | 112 mo ago | 216 | 2015 | Atsuo Shiraki Co-Founder & CTO | WordPressApple iCloud MailGoogle Workspace+30 | — | — | — |
| 22 | Geo40 Developer of silica extraction plants from geothermal fluids | $8M | 61 mo ago | 20 | 2010 | John Worth Chief Executive Officer | WordPressMySQLPHP+20 | — | — | 1 launch |
| 23 | Ubiden Provider of electric vehicle charging services | $7M | 10 mo ago | — | 2019 | Shuhei Onishi Co-Founder | DudaNginxSnowplow Analytics+13 | — | 14 patents Integrated energy management and payment processing systems for electric vehicles | — |
| 24 | Helical Fusion Provider of nuclear energy services | $6M | 1 mo ago | 10 | 2021 | Junichi Miyazawa Co-Founder | WixSentryEnvoy+12 | 3 signals Funding · Contracts | 8 patents Magnetic‑confinement fusion reactor structures and superconducting cable protection materials | 1 award |
| 25 | Miraikikai Developer of robots and laser sensors for various industrial applications | $6M | 93 mo ago | 24 | 2004 | Tohru Miyake Founder & CEO | WordPressMySQLPHP+21 | — | 39 patents Autonomous robots for cleaning and maintaining solar panel installations. | — |
| 26 | Toshiba Manufacturer and marketer of advanced electronic and electrical products | $6M | 13 mo ago | 1,328 | 1985 | — | HCL Digital ExperienceApple iCloud MailJava+25 | 6 signals ▼78% Acquisition · Regulatory · Announcements | 106,846 patents Patents concentrated in electrical & electronics | — |
| 27 | Japan Wind Tunnel Manufacturing Manufacturer of wind turbines and wind tunnels | $5M | 46 mo ago | 50 | 2016 | Joshua Lawn Founder & CEO | WordPressMySQLPHP+8 | — | — | — |
| 28 | AZUL Energy Manufacturer of air batteries | $3M | 28 mo ago | 376 | 2019 | Hiroya Abe Founder | WordPress Site EditorWordPressMySQL+11 | — | 41 patents Advanced catalysts and electrode designs for metal‑air batteries, water electrolysis, and fuel cells | — |
| 29 | Albatross Technology Developer of marine energy projects | $3M | 30 mo ago | 5 | 2011 | Hiromichi Akimoto CEO | WordPressMySQLPHP+17 | — | 18 patents Wave energy conversion using drag‑type bucket turbines for marine power generation | — |
| 30 | MiRESSO Developer of nuclear fusion power generation projects | $2M | 3 mo ago | — | 2023 | Masaru Nakamichi CEO | WordPressMySQLPHP+15 | — | — | — |
| 31 | Enerbank Supplier of electricity | $1M | 6 mo ago | 3 | 2018 | Yugo Sato Co-Founder | WordPressMySQLPHP+17 | — | — | — |
| 32 | Thermalytica Thermalytica is a clean-tech startup specializing in heat insulating and heat shielding materials. | $1M | 39 mo ago | — | 2021 | Kazuo Konuma Co-Founder & CEO | WordPressMySQLPHP+16 | — | 13 patents Thermal insulation sheets, heat‑insulating windows, and vapor‑deposition coating technologies for building envelopes. | — |
| 33 | Green Earth Institute Developer of fermentation production technology using biomass | $976K | 99 mo ago | 46 | 2011 | — | PleskGoogle MapsNginx+7 | — | — | — |
| 34 | OPTMASS Research & development of transparent solar cells and heat ray control technology | $386K | 25 mo ago | — | 2021 | Tohru Nakagawa CEO | NginxLodashjQuery+4 | — | 5 patents Infrared sensor modules integrating variable-resistance films and IR-absorbing resin layers. | — |
| 35 | Space Power Technologies Provider of an wireless power transmission equipment | $205K | 34 mo ago | 9 | 2019 | Minoru Furukawa CEO | WordPressMySQLPHP+15 | — | 24 patents Wireless power transmission systems and anti‑theft security for energy devices | — |
Top 12 Energy companies in Japan
#1
Series C · Minato City, Tokyo · founded 2018 · 50 employees$26.8Mraised▾
Manufacturer of PV and energy storage system
- Apr 2026Series C$5.4M
- Dec 2025Conventional Debt—
- Aug 2025Series C$21.4M
- Jan 2018Seed—
#2
Series C · Uji, Kyoto · founded 2019 · 90 employees$110.2Mraised▾
Provider of nuclear fusion reactor technology based on low-energy nuclear reaction technology. It uses core element technology and plant engineering technology to generate energy.
- Sep 2025Conventional Debt$35.9M
- Sep 2025Series C$9.8M
- Jul 2024Series C$6.8M
- Apr 2024Series C$10.2M
#3
Series B · Bakurocho, Ishikawa · founded 2021$12.7Mraised▾
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- Apr 2026Series B$12.7M
#4
Series B · Chiyoda City, Tokyo · founded 2021 · 10 employees$6.5Mraised▾
Provider of nuclear energy services
- Apr 2026Series B$16.9M
- Dec 2025Series A$5.6M
- Jul 2025Series A$15M
- Oct 2023Grant (prize money)$43M
#5
Series B · Minato, Tokyo · founded 2019 · 55 employees$14Mraised▾
Provider of energy marketing services
- Jan 2026Series B$32.4M
- Jan 2022Series A$14M
#6
Series A · Osaka, Osaka · founded 2021 · 9 employees$20.6Mraised▾
Manufacturer of nuclear fusion reactors
- Oct 2025Series A$2.6M
- Jun 2025Series A$16M
- Jun 2025Conventional Debt$2.1M
- Nov 2024Seed$7.2M
#7
Series D · Shinagawa, Tokyo · founded 2020 · 2 employees$29.9Mraised▾
Limited information available
- Jun 2025Series D$29.9M
- Apr 2024Series C—
- Aug 2022Seed—
#8
Series C · Chiyoda City, Tokyo · founded 2017 · 12 employees$23.1Mraised▾
Developer of renewable energy solutions and electricity trading platforms. It offers solar power systems, electricity retail services, and a platform for peer-to-peer energy trading. The company also conducts research and development in next-generation electricity systems, collaborating with universities and corporations. Its services aim to facilitate sustainable energy consumption and improve quality of life through innovative technology. It develops and provides electricity retail systems utilizing IoT and AI technologies.
- Jun 2025Series C—
- Mar 2025Series B$7.2M
- Jun 2020Series B$9.3M
- Sep 2018Series A$6.6M
#9
Series A · Misawa, Aomori · founded 2023$1.7Mraised▾
Developer of nuclear fusion power generation projects
- Feb 2026Series A$15.4M
- Aug 2025Series A$12.4M
- Mar 2024Seed$1.7M
#10
Series C · Minato, Tokyo · founded 2019$6.7Mraised▾
Provider of electric vehicle charging services
- Jul 2025Series C$6.7M
- Nov 2023Series B—
- Apr 2023Series B—
#11
Series B · Chiyoda City, Tokyo · founded 2020 · 18 employees$13.3Mraised▾
Supplier of electricity. It manufacturing, sales, import and export of wireless elements, antennas, high-frequency products and related equipments. It provides wireless power transfer systems.
- Feb 2025Series B$12M
- Feb 2025Venture Debt$6.7M
- May 2024Series B$13.3M
#12
Series B · Chuo City, Tokyo · founded 2018 · 3 employees$1.4Mraised▾
Supplier of electricity
- Nov 2025Series B$5.2M
- Dec 2024Series B$3.9M
- Oct 2022Series A$1.4M
- Jul 2020Seed—
Funding & investor landscape
Notable founders
Market landscape — 10 sub-themes by coverage
Share of Energy coverage by sub-theme.
Regulatory-risk over time rising
Funding & growth over time
funding rising · growth rising
How research on Grid Energy Storage is moving in Japan
A read on the academic research around Grid Energy Storage — which themes are gaining ground, the institutions and researchers driving them, and how the tone is shifting. Based on 945 Japan-affiliated papers.
- Korea University70
- The University of Tokyo64
- National Institute of Advanced Industrial Science and Technology55
- National Institute for Materials Science52
- Kyoto University51
- Electrode2→37
- Battery (electricity)9→40
- Electrochemistry6→34
- Anode4→28
- Electrolyte12→36
- Renewable energy9→107
- Battery (electricity)7→94
- Photovoltaic system3→68
- Power (physics)1→48
- Electrochemistry2→39
- Battery (electricity)1→20
- Renewable energy1→16
- Electrolyte2→14
- Nanotechnology4→12
- Electrochemistry1→7
Where energy storage is researched across Japan
Location clusters by institution affiliation — each city's volume, stance tone, and a quick read on its hot topic, what's advancing, the opening opportunity, and the main concern.
Who's filing energy storage patents in Japan
Japan energy storage patent filing is accelerating — 2,762 filings from 502 assignees (2016–2025), led by GS Yuasa INT, Sumitomo Electric Industries, Panasonic IP MAN; annual filings 196→248.
- GS Yuasa INT1009
- Sumitomo Electric Industries907
- Panasonic IP MAN122
- Showa Denko KK121
- Honda121
- KOBE Steel92
- Toyota56
- Toshiba KK55