Form Energy

Form Energy is an American energy-storage company established in 2017 to develop affordable, long-duration systems for electric grids increasingly supplied by intermittent renewable generation. Its principal technology is a rechargeable iron-air battery designed to store electricity for roughly 100 hours or longer. The system uses iron, water, and air rather than lithium-based active materials. During discharge, the battery takes oxygen from the air and converts metallic iron into rust; during charging, electricity reverses the reaction and converts the iron oxide back into iron. This reversible rusting process is intended to provide a low-cost way to shift electricity across several days and to support grid reliability during extended periods of low wind or sunlight. The company was founded by Mateo Jaramillo, a former head of battery development at Tesla; MIT materials scientist Yet-Ming Chiang; Ted Wiley; William Woodford; and Marco Ferrara. Form Energy's founding team combined experience in battery research, industrial development, and energy-market applications. Rather than concentrating on short-duration frequency regulation or daily peak shifting alone, the company positioned its technology for multi-day and potentially year-round grid balancing, where conventional lithium-ion systems can become expensive because of the amount of storage capacity required. Form Energy describes its battery as a modular system. Individual battery modules are approximately the size of a washing machine and contain a water-based, non-flammable electrolyte together with stacks of iron and air electrodes. Modules are assembled into megawatt-scale power blocks, and multiple blocks are connected into larger grid installations. The architecture is intended to allow projects to scale in increments while using materials that are relatively abundant and familiar to heavy industry. The company has stated that its systems can deliver energy for 100 or more hours and has promoted a cost target substantially below that of lithium-ion storage for very long durations; such cost claims are company assertions rather than independently established financial results. Form Energy's commercial development accelerated through strategic investment, utility agreements, and plans for domestic manufacturing. In 2021, it announced a $240 million Series D financing round led by ArcelorMittal's XCarb innovation fund. In 2022, it announced a $450 million Series E round led by TPG Rise Climate. Other reported investors include Breakthrough Energy Ventures, Coatue Management, ArcelorMittal, Temasek, Energy Impact Partners, Prelude Ventures, The Engine, Capricorn Investment Group, Eni Next, Macquarie Capital, NGP Energy Technology Partners III, and Perry Creek Capital. In December 2022, Form Energy selected a 55-acre site in Weirton, West Virginia, for its first manufacturing plant. The project was reported at an expected cost of $760 million, with projected employment of approximately 750 people and partial support from $105 million in West Virginia surplus tax funds. In January 2023, Xcel Energy contracted for two proposed systems, one in Pueblo, Colorado, and another in Becker, Minnesota. Each was described as a 10-megawatt installation with up to 100 hours of duration and approximately 1 gigawatt-hour of storage capacity. The company has also worked on the underlying electrochemistry and manufacturing process. In 2024, it described an engineering approach for converting powdered iron ore into metallic iron through a low-temperature alkaline process driven by electricity. The approach is intended to operate continuously, achieve high efficiency, and support incremental scaling. Form Energy also reported that its cells underwent UL9540A fire testing in 2024. Its business remains focused on commercializing long-duration storage rather than operating as a conventional electricity retailer or a consumer battery brand.

Form Energy emerged in 2017 as a specialist energy-storage company focused on a problem created by the increasing use of wind and solar power: renewable generation can be inexpensive when available, but output may fall for periods lasting many hours or several days. Existing lithium-ion batteries are effective for short-duration applications and daily cycling, yet their cost can rise sharply when they are sized to provide very long periods of backup. Form Energy was created to pursue a different chemistry and system design for this multi-day requirement. The founding group included Mateo Jaramillo, who had led battery development at Tesla, MIT professor and battery scientist Yet-Ming Chiang, Ted Wiley, William Woodford, and Marco Ferrara. Their work centered on an iron-air electrochemical system based on reversible oxidation. When the battery discharges, iron reacts with oxygen drawn from the surrounding air and becomes rust. During charging, an electric current reverses the reaction, restoring metallic iron and releasing oxygen. Water-based electrolyte and iron-based active materials are central to the design, which the company presents as non-flammable and dependent on relatively common industrial inputs. Form Energy's system is organized from cell to grid installation. Individual modules contain many meter-scale cells with iron and air electrodes immersed in electrolyte. The modules are combined into power blocks, and power blocks are grouped into larger systems connected to the electricity grid. The company has described a nominal duration of about 100 hours or more, allowing a project to shift renewable electricity across several days rather than merely from afternoon to evening. It has also claimed that long-duration storage using its chemistry could cost less than one-tenth as much as lithium-ion technology in comparable long-duration applications; this is a company claim and should not be treated as independently verified financial performance. The business attracted significant climate-technology investment as it moved from laboratory development toward commercial production. In August 2021, Form Energy announced a $240 million Series D financing round led by ArcelorMittal's XCarb innovation fund. In October 2022, it announced a $450 million Series E round led by TPG Rise Climate. The investor group reported in reference material also included Breakthrough Energy Ventures, Coatue Management, ArcelorMittal, Perry Creek Capital, NGP Energy Technology Partners III, Temasek, Energy Impact Partners, Prelude Ventures, The Engine, Capricorn Investment Group, Eni Next, and Macquarie Capital. A major commercialization step came in December 2022, when Form Energy announced Weirton, West Virginia, as the site of its first manufacturing plant. The proposed facility was planned for a 55-acre site, with an expected investment of $760 million and approximately 750 jobs. The project was to receive partial support from West Virginia, including $105 million in surplus tax funds. The planned factory connected Form Energy's technology to a regional industrial base with experience in steelmaking and iron-related manufacturing. In January 2023, Xcel Energy contracted for two proposed Form Energy systems. One was planned for Pueblo, Colorado, and the other for Becker, Minnesota. Each project was described as providing 10 megawatts of instantaneous power for as long as 100 hours, corresponding to approximately 1 gigawatt-hour of stored energy. These agreements represented an attempt to move the iron-air system from technology development into utility-scale deployment. Form Energy continued to develop its materials and production processes. In 2024, it described a method for converting powdered iron ore into metallic iron using a low-temperature alkaline solution activated by electric current. The company said the process could operate continuously, maintain high efficiency, and scale in smaller increments. It also reported UL9540A fire testing of its cells, a safety-evaluation milestone relevant to stationary energy-storage projects. The company is not a publicly traded electricity utility or a consumer electronics brand. It is a private technology and manufacturing company whose main commercial proposition is long-duration storage for utility, renewable-energy, and large-load applications. Reference material also reports a 2026 clean-energy battery supply agreement with Google for a Minnesota data center. Because Form Energy's deployment pipeline, manufacturing output, and commercial financial results are not fully documented in the supplied material, its ultimate market scale remains subject to further verification.

1. 2026Google supply agreement reported

   Reference material reports a clean-energy battery supply agreement with Google for a Minnesota data center.

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2. 2024Iron-processing and safety-engineering developments

   Form Energy describes a low-temperature iron-production process and reports UL9540A fire testing of its cells.

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3. 2023Xcel Energy orders two proposed systems

   Xcel Energy contracts for proposed systems in Colorado and Minnesota, each designed for 10 megawatts and up to 100 hours of storage.

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4. 2022Series E financing

   The company announces a $450 million Series E financing led by TPG Rise Climate.

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5. 2022Weirton manufacturing site announced

   Form Energy selects a 55-acre site in Weirton, West Virginia, for a planned first manufacturing plant.

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6. 2021Series D financing

   Form Energy announces a $240 million Series D round led by ArcelorMittal's XCarb innovation fund.

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7. 2017Form Energy is founded

   Mateo Jaramillo, Yet-Ming Chiang, Ted Wiley, William Woodford, and Marco Ferrara establish Form Energy to develop long-duration grid-storage technology.

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Long-duration energy-storage technology provider focused on low-cost, multi-day grid storage for renewable-energy integration and reliability.

• Iron-air battery systemLong-duration grid energy storage

  Form Energy's principal commercial product is a rechargeable iron-air battery system intended to store electricity for approximately 100 hours or longer. Its electrochemical cycle uses iron, water, and oxygen from ambient air: discharge converts iron into rust, while charging reverses the reaction. Individual modules contain stacks of iron and air cells in a water-based electrolyte. Modules are assembled into megawatt-scale power blocks and connected into larger utility installations. The system is designed for renewable-energy shifting and multi-day grid reliability rather than consumer electronics or short-duration backup alone.

• Megawatt-scale power blocksStationary storage infrastructure

  Power blocks are modular assemblies that combine large numbers of iron-air battery modules inside environmentally protected enclosures. Multiple blocks can be deployed together to form grid-connected installations ranging from utility projects to larger renewable-energy support systems. The modular architecture is intended to permit incremental project sizing and to achieve higher storage density where required.

• 2026Google clean-energy battery supply agreementStrategy

  Large data centers require dependable electricity and may use clean-energy storage to complement renewable generation.

  What changed. Reference material reports that Google contracted with Form Energy for a battery supply agreement intended to support a Minnesota data center.

  Aftermath. The reported agreement would extend Form Energy's target market beyond utility procurement to large commercial electricity users.

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• 2023Contract for two Xcel Energy storage systemsProduct launch

  Xcel Energy sought long-duration storage projects capable of supporting renewable generation and grid reliability.

  What changed. Form Energy contracted to supply proposed systems for Pueblo, Colorado, and Becker, Minnesota, each specified at 10 megawatts and up to 100 hours of duration.

  Aftermath. The agreements gave Form Energy two utility-scale reference projects and demonstrated an intended commercial use for its iron-air technology.

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• 2022Select Weirton for the first manufacturing plantStrategy

  Form Energy needed domestic production capacity to move its iron-air technology from development toward utility-scale commercialization.

  What changed. The company selected a 55-acre site in Weirton, West Virginia, for a planned $760 million factory expected to employ approximately 750 people.

  Aftermath. The decision established a manufacturing base and linked the company's industrial strategy to West Virginia public support and the region's steel-related capabilities.

  Expected plant investment. $760 million (2022 announcement)

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• 2026Google enters a clean-energy battery supply agreement with Form Energy

  Reference material reports that Google contracted with Form Energy for a clean-energy battery supply agreement intended to support a data center in Minnesota.

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• 2024Form Energy reports iron-processing and battery-safety developments

  The company described an electricity-driven process for converting powdered iron ore into metallic iron and reported UL9540A fire testing of its cells.

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• 2023Xcel Energy contracts for two Form Energy storage systems

  Xcel Energy contracted for proposed 10-megawatt, 100-hour systems in Pueblo, Colorado, and Becker, Minnesota.

  Product launch
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• 2022Form Energy raises $450 million in Series E financing

  Form Energy announced a Series E round led by TPG Rise Climate, adding capital for technology development and commercialization.

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• 2022Form Energy selects Weirton, West Virginia, for first manufacturing plant

  The company announced plans for a 55-acre manufacturing site, with an expected project cost of $760 million and projected employment of about 750 workers.

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• 2021Form Energy closes $240 million Series D financing

  The company announced a Series D financing round led by ArcelorMittal's XCarb innovation fund to support development of its long-duration iron-air battery technology.

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1. Form Energy
2. Form Energy official website