Updated October 19, 2026 October 19 update: debt finance joins the factory ramp Form Energy announced a $270 million credit facility on September 21, adding a new source of manufacturing and working capital after its August equity raise. The facility combines revolving credit with an advance facility tied to tax credits generated by eligible component production under Section 45X. Form says proceeds will support its iron-air battery manufacturing at Form Factory 1 in Weirton, West Virginia. The tax-credit advance facility includes an accordion feature that can bring total credit under the debt facility to as much as billion. That is potential expanded capacity, not an announcement that Form has received or drawn billion. The release does not disclose how much of the initial facility had been drawn, its interest rate, or a detailed repayment schedule. Keep equity, borrowing capacity, and orders separate The company’s August 12 announcement reported a $750 million Series G led by T. Rowe Price and more than $2 billion in total equity raised. Its September facility is debt finance, not another equity round. Combining the two as if both were unrestricted cash already spent on factories would obscure the different funding mechanisms. Tax-credit advances can help bridge the interval between producing eligible components and realizing the associated credit value. They do not remove production requirements. Manufacturing yield, quality control, supplier payments, and the timing of customer acceptance still determine how smoothly a factory converts its order book into revenue. The updated backlog is 80 GWh, not installed capacity Form’s August release says its backlog increased from approximately 20 GWh to 80 GWh earlier in 2026, naming Xcel Energy and Google, Crusoe, and FuturEnergy Ireland among the associated customers and projects. This supersedes the 75 GWh pipeline figure used in earlier versions of this profile. Backlog is a commercial commitment measure, not a tally of commissioned batteries or energy already delivered to the grid. For scale only, 80 GWh divided by a 100-hour discharge duration equals 800 MW. That calculation is not a fleet power rating because individual project designs and operating conditions differ. It illustrates why long-duration storage announcements need both power and energy units: a large GWh total does not by itself identify how much instantaneous load a portfolio can support. What the financing does not prove The September release establishes financing arrangements, not completion of the customer projects described below. Announced delivery dates should still be treated as project targets unless the customer or operator confirms commissioning. Buyers need evidence of usable capacity, sustained discharge performance, availability, and service support at the installed-system level. The August announcement also named Navneet Govil as chief financial officer and Wes Sloan as chief operating officer. Those appointments put finance and manufacturing leadership alongside the new capital. The next test is whether that organization can turn the company-reported backlog into repeatable production and accepted customer systems, rather than another larger headline number. Primary sources checked October 19, 2026 Form Energy, September 21, 2026: credit facility Form Energy, August 12, 2026: Series G and backlog Iron rusts. Most engineers spend careers trying to prevent that. Form Energy has spent eight years making it useful. The Cambridge, Massachusetts company has built a rechargeable battery that runs on iron, water, and air , stores electricity for 100 hours or more, and costs a fraction of what lithium-ion systems charge per kilowatt-hour of usable capacity. Founded in 2017 and backed by more than $2 billion in cumulative private funding , Form Energy has moved from sub-scale lab cells to a 550,000-square-foot factory on the site of a former steel mill in Weirton, West Virginia. Its commercial pipeline now exceeds 80 GWh of contracted projects , including what would be the largest grid battery ever built. AI-generated image Form Factory 1, built on the 55-acre site of the former Weirton Steel mill in Weirton, West Virginia. $2B+ Cumulative private funding 100+ Hours of discharge duration 80 GWh Commercial pipeline under agreement 550K sq ft Form Factory 1, Weirton WV $750M Series G raised (Aug. 2026) 750+ Projected WV jobs at full capacity Five Founders, One Very Old Element Form Energy came together in 2017 through a combination of MIT lab access and a shared conviction: the electricity grid needed storage that could last days, not hours. Lithium-ion, the dominant chemistry at the time, was proving excellent for four-hour applications but economically impractical for the multi-day storage that would be needed as solar and wind generation expanded. The five co-founders each brought distinct expertise. Mateo Jaramillo , who became CEO, had led Tesla's energy storage products and programs as Vice President at Tesla Energy. Ted Wiley , a co-founder and early operations leader, handled operations from the start. Billy Woodford took the role of Chief Technology Officer, focused on battery engineering. Yet-Ming Chiang , an MIT professor and one of the most cited materials scientists working on electrochemistry, became Chief Science Officer. Marco Ferrara , Chief Digital Officer, rounded out the team with software and digital systems expertise. The group launched with seed funding and early lab space from MIT's The Engine, a venture firm spun out of the institute to support companies with long development timelines and genuine technical risk. That origin shaped Form Energy's approach: patient, science-first, and skeptical of shortcuts. Why Not Lithium? Lithium-ion batteries are exceptional at what they do, but their cost structure works against multi-day storage. A four-hour lithium-ion system might run $200 to $300 per kilowatt-hour. Stretch that to 100 hours and the economics collapse: you need 25 times more energy capacity for the same power output, multiplying the hardware cost proportionally. Form Energy's target cost for iron-air is under $20 per kilowatt-hour of energy capacity , which is what makes the math work for week-long storage at grid scale. Early R&D moved quickly. The company validated its core iron-air chemistry by 2019 and produced its first full-scale cell in 2020, the same year it announced its first customer agreement with Great River Energy, a Minnesota electric cooperative. A Series A of $9 million led by Breakthrough Energy Ventures had grown into a Series B of $40 million by 2019, funding the chemistry work and initial manufacturing research. How a Battery Built on Rust Actually Works The iron-air battery operates on a chemical reaction that anyone who has left a bicycle outside in the rain has witnessed. During discharge, iron pellets inside the battery cells react with oxygen drawn in from the surrounding air, forming iron oxide, more commonly known as rust. That oxidation reaction releases electrons, generating electrical current. During charging, electricity reverses the process: the iron oxide sheds its oxygen back into the air, returning the material to metallic iron. The battery breathes in oxygen when working and breathes it out when refueling. The electrolyte is a water-based alkaline solution, non-flammable by nature. There is no lithium, no cobalt, no nickel, and no rare-earth material anywhere in the active chemistry. Iron is the fourth most abundant element in Earth's crust. It is cheap, widely mined in the United States, and fully recyclable at the end of a battery's life. Iron-Air Battery: Key Technical Specs • Discharge duration: 100+ hours at nameplate power output. • Round-trip efficiency: Approximately 40 to 60 percent (lower than lithium-ion's 85 to 90 percent, but acceptable at this price point for multi-day applications). • Active material cost: Less than $1 per kilowatt