Form Energy
Iron-air batteries for multi-day storage
Ranked #1 in Best Battery Startups, and on 1 more ranking.
Form Energy, based in Somerville, Massachusetts, makes iron-air batteries that store energy for up to 100 hours. Its first commercial project, a 1.5 MW system with Great River Energy in Cambridge, Minnesota, is targeting commercial operation by the end of 2026.
At a glance
| Price from | Custom |
| Best for | Utilities planning multi-day backup for wind and solar |
From Form Energy's own website.
What stands out
- Stores energy for days, not hours
- Uses low-cost iron
Worth knowing
- First projects running behind schedule
- Early commercial stage
How it ranks
Form Energy is ranked 1st of 10 in Best Battery Startups (Lister Score 97.0) and 4th of 10 in Best Climate Tech Startups (Lister Score 93.1).
#1 in Best Battery Startups · Lister Score 97.0
Form Energy, founded in 2017 in Somerville, Massachusetts, makes iron-air batteries that store electricity for up to 100 hours, built at its Form Factory 1 in Weirton, West Virginia. In August 2026 it raised a $750 million Series G led by T. Rowe Price, taking total equity raised to over $2 billion.
Form Energy says its backlog grew from about 20 GWh to 80 GWh, with new agreements including Xcel Energy, Google and Crusoe..
| Rank | Best Battery Startups | Score |
|---|---|---|
| 1 | Form Energy | 97.0 |
| 2 | Group14 Technologies | 95.7 |
| 3 | Lyten | 94.4 |
| 4 | Verkor | 93.1 |
| 5 | Peak Energy | 91.8 |
| 6 | Nyobolt | 90.5 |
| 7 | EnerVenue | 89.2 |
| 8 | Base Power | 87.9 |
| 9 | Alsym Energy | 86.6 |
| 10 | Echion Technologies | 85.3 |
#4 in Best Climate Tech Startups · Lister Score 93.1
Form Energy, founded in 2017 and based in Somerville, Massachusetts, makes iron-air batteries that store electricity for up to 100 hours, built at its factory in Weirton, West Virginia. It raised a $750 million Series G in August 2026.
Form signed a 12 GWh battery agreement with Crusoe Energy for AI data centres in March 2026..
| Rank | Best Climate Tech Startups | Score |
|---|---|---|
| 1 | Redwood Materials | 96.9 |
| 2 | Octopus Energy | 95.6 |
| 3 | Fervo Energy | 94.4 |
| 4 | Form Energy | 93.1 |
| 5 | Antora Energy | 91.8 |
| 6 | Watershed | 90.5 |
| 7 | Group14 Technologies | 89.2 |
| 8 | Twelve | 87.9 |
| 9 | Heirloom | 86.6 |
| 10 | Rondo Energy | 85.3 |
Frequently asked questions
How does Form Energy rank on Lister?
Form Energy is ranked 1st of 10 in Best Battery Startups (Lister Score 97.0) and 4th of 10 in Best Climate Tech Startups (Lister Score 93.1).
Appears in
Best Battery Startups
1Form Energy97.02
Group14 Technologies95.73
Lyten94.4RANKINGfull ranking →STARTUPSVERIFIEDBest Climate Tech Startups
1
Redwood Materials96.92
Octopus Energy95.63
Fervo Energy94.4RANKINGfull ranking →- #10 in Best Energy Storage Companies · Deep Tech
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