Form Energy

Private (Series G closed August 2026; listing targeted for 2027)Founded 2017🇺🇸Somerville, Massachusetts

CEO

Mateo Jaramillo

Data verified as of Aug 28, 2026

Summary

Form Energy, founded in 2017 by former Tesla energy chief Mateo Jaramillo, MIT professor Yet-Ming Chiang, Ted Wiley, Billy Woodford and Marco Ferrara, is building the storage technology that lithium-ion cannot economically reach: a 100-hour battery. Its iron-air cells run on reversible rusting, oxidising iron with air from the atmosphere to discharge and converting the rust back to iron to charge, using materials so cheap the company claims a cost per kilowatt-hour a fraction of lithium-ion's. That makes multi-day storage viable, the duration Jaramillo argues is where batteries stop shaving peaks and start replacing thermal power plants. The company manufactures at Form Factory 1, a 550,000 square-foot plant in Weirton, West Virginia built on a former tin mill site, which is now in production and has begun delivering its first commercial system, a 1.5 MW / 150 MWh project with Great River Energy in Cambridge, Minnesota. Demand arrived faster than anyone expected once AI data centers started hunting for firm power: Form has more than 80 GWh of commercial projects under agreement, including a 300 MW / 30 GWh system with Google and Xcel Energy announced in February 2026 that Xcel calls the largest battery project by energy capacity ever announced, a 12 GWh capacity agreement with Crusoe for AI data centers starting in 2027, and its first deployment outside the US, a 1 GWh project with FuturEnergy Ireland. Form has raised more than $2B to date, including a $750M Series G led by T. Rowe Price that closed in August 2026, has picked JPMorgan and Jefferies to lead its IPO, and plans to go public in 2027.

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Aug 12
Form Energy raises $750M Series G to scale battery output
Form Energy said on August 12 it closed a $750 million Series G led by T. Rowe Price, with participation from Sequoia Capital, Janus Henderson, Franklin Templeton, GE Vernova, Coatue and other existing and new investors, taking the company's total funding raised to more than $2 billion. The round funds continued manufacturing scale-up of Form's 100-hour iron-air batteries at its Weirton, West Virginia factory, where a nearly 300,000 square-foot expansion is already under construction, and follows the company's disclosure that its commercial order book has more than tripled to over 80 GWh on demand from AI data center operators including Google and Crusoe.
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Main Products

Iron-Air Multi-Day Battery

Active

A grid storage system built from modules the size of a washing machine, each filled with iron electrodes and a water-based alkaline electrolyte. Discharging oxidises the iron with oxygen drawn from the air; charging reverses the reaction and turns the rust back into metallic iron. Because the active materials are iron, water and air, the cost per kilowatt-hour is a small fraction of lithium-ion's, which is what makes 100-hour duration economic. Systems are assembled into multi-acre installations sized from megawatts to hundreds of megawatts.

In production at Form Factory 1; first commercial system being delivered to Great River Energy in Minnesota, with the 80+ GWh order book delivering from 2027

What's Next

Bring the first commercial iron-air system online in Minnesota

The 1.5 MW / 150 MWh Cambridge Energy Storage Project with Great River Energy is the first commercial deployment of iron-air anywhere. Delivery of the system has started and the full project is expected to come online during 2026, the first real-world proof that a 100-hour battery works on a live grid.

2026

Begin Crusoe deliveries for AI data centers

The 12 GWh strategic capacity agreement with Crusoe starts delivering in 2027, with every system built at Form Factory 1 in Weirton. It is the first of Form's AI-driven agreements to reach hardware.

2027

Go public

Form plans an initial public offering in 2027, which would make it the first pure-play long-duration storage manufacturer on the public markets and the clearest test yet of whether investors will underwrite multi-day storage economics. Form selected JPMorgan and Jefferies as lead bookrunners on June 17, 2026, an early concrete step toward the listing.

2027

Deliver the first international iron-air project in Ireland

Ballynahone Energy Storage, a 10 MW / 1 GWh iron-air system with FuturEnergy Ireland in County Donegal, is Form's first deployment outside the US and is meant to demonstrate multi-day storage's role in Irish grid reliability. Targeted online in 2029.

2029

Ship the first modules for the Google and Xcel 30 GWh project

Form expects to ship the first modules for the 300 MW / 30 GWh Minnesota system by the end of 2028. At 30 GWh it would be the largest battery project by energy capacity ever built, and the deployment that decides whether iron-air scales from pilots to infrastructure.

End of 2028

Reach 500 MW / 50 GWh of annual manufacturing capacity

The Weirton expansion targets more than 1 million square feet of manufacturing space and at least 500 MW / 50 GWh of annual output by 2028, the throughput the 80+ GWh order book requires.

2028

Bring the Dominion Energy Darbytown iron-air pilot online

An 8.94 MW iron-air pilot at Dominion Energy's Darbytown Power Station in Henrico County, Virginia, approved by the Virginia State Corporation Commission in May 2024, is targeted to be operational by late 2026 alongside a separate zinc-hybrid pilot from Eos Energy at Virginia State University.

Late 2026

Track Record

2 of 3 announced dates hit · 1 slipped

Close the pre-IPO round of up to $500M

Target Late 2026 · Resolved Aug 12, 2026

Form closed a $750M Series G on August 12, 2026, led by T. Rowe Price, exceeding the up-to-$500M target and taking total funding raised past $2B. The company still expects this to be its last private round before a 2027 IPO.

Hit

Bring the Cambridge, Minnesota iron-air project online by late 2025

Target Late 2025 · Resolved Mar 24, 2026

The 1.5 MW / 150 MWh project with Great River Energy did not reach operation in 2025. Form began delivering the system in early 2026 and now expects the full project to come online during 2026.

Slipped

Start high-volume production at Form Factory 1

Target 2025 · Resolved Mar 24, 2026

Form confirmed it had launched production at the Weirton plant and commenced delivery of its first commercial system, moving iron-air from prototype to manufactured product. A nearly 300,000 square-foot expansion of the factory is now under construction.

Hit

Operations & Revenue

StatusOperational - production started, first commercial system in delivery

Form crossed from demonstration into manufacturing in 2026: Form Factory 1 in Weirton is running high-volume production, the first commercial system is being delivered to Great River Energy in Cambridge, Minnesota, and a nearly 300,000 square-foot factory expansion is under construction toward a 2028 goal of 500 MW / 50 GWh of annual capacity. The demand side has been transformed by AI and is starting to go international. Google's 300 MW / 30 GWh commitment with Xcel and Crusoe's 12 GWh agreement pushed the order book past 80 GWh by June 2026 (more than tripled from ~20 GWh in 2025), and Form's first project outside the US - a 1 GWh iron-air system with FuturEnergy Ireland - shows the demand base broadening beyond US data centers. The risks are the ordinary ones for a first-of-a-kind industrial product: no iron-air system has yet run a full commercial year on a grid, the Minnesota pilot has already slipped from a late-2025 to a 2026 start, and Google's modules are not expected to ship until the end of 2028, so most of the pipeline is a promise rather than a delivery.

Revenue Streams

Utility-scale multi-day storage systems

Sales of iron-air battery systems to regulated utilities and cooperatives for renewable firming and winter reliability, including Great River Energy, Xcel Energy, Georgia Power and Dominion Energy, plus Form's first deployment outside the US - the 10 MW / 1 GWh Ballynahone project with FuturEnergy Ireland.

Data center capacity agreements

Large multi-gigawatt-hour supply commitments to AI infrastructure buyers, now the largest part of the pipeline: 30 GWh for Google via Xcel and 12 GWh for Crusoe, with deliveries from 2027.

Key Metrics

Employees: ~1,000 (West Virginia, Massachusetts and California)
Est. Annual Revenue: Not disclosed. Form is pre-scale on revenue: production started in 2026 and the first commercial system is only now being delivered, against an 80+ GWh order book whose deliveries run from 2027 onward.
Storage duration: 100 hours at rated power - roughly 25x a standard 4-hour lithium-ion system
Commercial pipeline: 80+ GWh of projects under agreement, more than tripled from ~20 GWh in 2025; reconfirmed as of the August 2026 Series G raise
First international deployment: Ballynahone Energy Storage - 10 MW / 1 GWh iron-air project with FuturEnergy Ireland in County Donegal, targeted online 2029
Largest single project: 300 MW / 30 GWh with Google and Xcel Energy - the largest battery project by energy capacity announced worldwide
Total funding raised: Over $2B, including a $750M Series G closed in August 2026, the final private round expected before a 2027 IPO
Series G valuation: About $1.75B pre-money, down from about $3B pre-money in the October 2024 Series F - a down round even as the commercial order book more than tripled
Form Factory 1: 550,000 sq ft in Weirton, West Virginia, in production; nearly 300,000 sq ft expansion under construction toward ~850,000 sq ft
2028 manufacturing target: 500 MW / 50 GWh of annual capacity across 1M+ sq ft
Utility customers: Georgia Power, Xcel Energy, Dominion Energy (8.94 MW pilot at Darbytown Power Station, Henrico County, VA), Great River Energy, NYSERDA, California Energy Commission, FutureEnergy Ireland

Timeline

2026Google and Xcel commit to a 300 MW / 30 GWh system

On February 24, 2026 Google and Xcel Energy announce plans for a 300 MW / 30 GWh iron-air battery on Xcel's Upper Midwest grid to serve a Minnesota data center, which Xcel calls the largest battery project by gigawatt-hour capacity announced anywhere to date. Google covers the buildout through a clean transition tariff; Form expects to ship the first modules by the end of 2028.

202612 GWh capacity agreement with Crusoe for AI data centers

On March 24, 2026 Form and Crusoe announce a strategic capacity agreement for 12 GWh of multi-day storage to support AI data centers, with deliveries starting in 2027 and every system built at Form Factory 1. Form discloses more than 75 GWh of commercial projects under agreement.

2026Production launched and first commercial system delivered

Form confirms high-volume production is running at Form Factory 1 and that it has begun delivering the first commercial pilot system in Minnesota, with construction underway on a nearly 300,000 square-foot expansion of the Weirton plant.

2026Pipeline triples past 80 GWh; first international project announced in Ireland

Form Energy's contracted commercial portfolio more than triples to over 80 GWh, up from about 20 GWh in 2025, on the strength of the Google/Xcel and Crusoe agreements. The company also announces Ballynahone Energy Storage, a 10 MW / 1 GWh iron-air project with FuturEnergy Ireland in County Donegal, its first deployment outside the United States, targeted online in 2029.

2024Factory built in a year; $405M Series F with GE Vernova

Form completes the 550,000 square-foot Weirton plant within a year of breaking ground and passes UL9540A fire safety testing. In October it closes a $405M Series F led by T. Rowe Price and GE Vernova, which also signs a strategic collaboration MOU, taking total funding past $1.2B.

2024First commercial project breaks ground in Minnesota

Form and Great River Energy break ground in Cambridge, Minnesota on a 1.5 MW / 150 MWh iron-air system, the first commercial deployment of the technology anywhere.

2022$450M Series E and the Weirton factory decision

A TPG Rise-led $450M Series E funds commercialisation, and in December Form announces Form Factory 1 on a 55-acre former tin mill site in Weirton, West Virginia, a roughly $760M investment supported by a $105M state package.

2021$240M Series D and the iron-air reveal

Form emerges from stealth with its iron-air chemistry and raises a $240M Series D led by ArcelorMittal's XCarb fund, pairing the battery with a steelmaker that supplies the iron.

2017Founded to solve multi-day storage

Mateo Jaramillo, who built Tesla's stationary storage business, teams up with MIT battery scientist Yet-Ming Chiang, Ted Wiley, Billy Woodford and Marco Ferrara to attack the one storage problem lithium-ion cannot solve economically: holding energy for days rather than hours.

Funding

Cumulative disclosed raise · dated rounds

Round	Date	Amount	Investors
Series D	Aug 2021	$240M	ArcelorMittal XCarb (lead), Breakthrough Energy Ventures, Temasek, The Engine, Coatue
Series E	Oct 2022	$450M	TPG Rise Climate (lead), existing investors
Series F	Oct 2024	$405M	T. Rowe Price and GE Vernova (co-leads), TPG Rise Climate, Breakthrough Energy Ventures, Capricorn, Coatue, Energy Impact Partners, The Engine Ventures, NGP, Temasek, GIC, Prelude Ventures
Series G	Aug 2026	$750M (a down round: about $1.75B pre-money valuation, down from about $3B pre-money in the October 2024 Series F)	T. Rowe Price (lead), Sequoia Capital, Janus Henderson, Franklin Templeton, PEAK6 Investments, Prelude Ventures, Engine Ventures, TPG Rise Climate, Capricorn's Technology Impact Funds, Breakthrough Energy Ventures, Dustin Moskovitz and Cari Tuna, Gigascale Capital, Coatue, Energy Impact Partners, NGP, GE Vernova, Blindspot Ventures, M&G Catalyst Fund