Form Energy is building a massive iron-air battery factory in Weirton, West Virginia, designed to deliver a storage system capable of discharging power for up to 100 hours, with Google among the high-profile customers driving demand for long-duration backup. The project sits at the intersection of two pressing forces: Big Tech’s insatiable appetite for reliable, carbon-free electricity, and a federal push to reshore advanced manufacturing. How the battery performs, and whether regulators in states like Minnesota clear the path for utilities to buy similar technology, will shape whether iron-air storage moves from pilot curiosity to grid-scale reality.
Iron-Air Storage and the Weirton Factory
Most grid batteries today rely on lithium-ion chemistry, which works well for short bursts of two to four hours but becomes prohibitively expensive when stretched to multi-day backup. Iron-air cells take a different approach: they “breathe” oxygen to rust and un-rust iron, a reversible reaction that is slow but cheap enough to sustain discharge over days rather than hours. That distinction matters for data centers, hospitals, and utilities that need to ride through extended weather events or prolonged supply disruptions without firing up diesel generators. If the chemistry performs as advertised, it could fill the gap between fast-responding lithium packs and seasonal resources like hydropower or hydrogen.
Form Energy chose the site of a former steel mill in Weirton for what it calls Form Factory 1. A tour of the construction progress at the Weirton plant drew attention from the U.S. Senate Committee on Energy and Natural Resources, which published details about the facility’s scale and workforce targets. The location carries symbolic weight: a rust-belt town that once produced steel is now set to manufacture batteries built around iron (the same base metal) repurposed for a clean-energy supply chain. The factory is expected to anchor a domestic production line at a time when policymakers across both parties have grown wary of depending on overseas suppliers for critical energy hardware, and it positions West Virginia as an early hub for long-duration storage manufacturing rather than a late adopter.
Why Google Needs 100-Hour Backup
Google has publicly committed to operating its data centers on carbon-free energy around the clock by the end of this decade. Wind and solar cover much of that demand during normal conditions, but they cannot guarantee uninterrupted supply during multi-day heat domes, ice storms, or grid failures. A 100-hour iron-air battery fills the gap that lithium-ion cannot economically reach. Rather than sizing a lithium system large enough to cover four days of outage, which would require enormous cell counts and cooling infrastructure, a single iron-air installation can deliver the same duration at a fraction of the material cost because iron is abundant and globally available. That longer-duration profile also pairs better with weather-driven events that can depress renewable output for several days at a time.
The partnership also signals a broader shift in how hyperscale cloud operators think about resilience. Traditional backup has meant rows of diesel generators, each carrying fuel-supply risk and carbon liability. Replacing that fleet with electrochemical storage eliminates direct emissions and removes the logistical headache of fuel delivery during the exact emergencies when roads and pipelines may be compromised. For Google, the calculus is straightforward: long-duration batteries protect uptime, satisfy corporate climate targets, and reduce regulatory exposure in jurisdictions that are tightening emissions rules for backup power. For utilities serving large data centers, the move offers a potential relief valve, because customer-sited storage can shoulder some of the reliability burden that would otherwise fall entirely on the bulk power system.
West Virginia’s Manufacturing Bet
The Weirton factory represents a significant public-private wager. According to the U.S. Senate energy committee, the project involves a large direct investment in a state that has spent decades losing industrial jobs. West Virginia offered incentives to attract the facility, betting that advanced battery manufacturing can replace some of the economic activity lost as coal and steel declined. The factory is expected to generate both construction-phase employment and permanent positions once production begins, and local officials have framed it as a cornerstone of a broader transition toward clean-tech manufacturing.
Whether that bet pays off depends on demand. If utilities and corporate buyers place enough orders, Form Factory 1 could become the anchor of a domestic iron-air supply chain, drawing in suppliers of processed iron, balance-of-plant components, and engineering services. If adoption stalls, the state faces the familiar risk of subsidizing a factory that never reaches full capacity. The early signals are encouraging: Google’s involvement provides a creditworthy anchor customer, and the broader market for multi-day storage is growing as extreme weather events expose the fragility of grids designed around steady baseload generation. Still, iron-air technology has not yet operated at commercial scale for years on end, and real-world degradation rates, maintenance needs, and community impacts remain open questions that only time and deployment data will answer.
Minnesota Regulators Open the Door
Hundreds of miles north, Minnesota is creating regulatory conditions that could accelerate adoption of long-duration storage. The Minnesota Department of Commerce announced a settlement with Xcel Energy that the department described as dramatic progress for Minnesotans to save money and protect the environment with cleaner homegrown energy. The Minnesota Public Utilities Commission accepted the settlement, which is tied to Xcel’s Integrated Resource Plan and includes provisions allowing investment in new and innovative clean resources. That language is broad enough to cover iron-air batteries alongside other emerging technologies such as advanced geothermal or grid-enhancing technologies, giving utilities a clearer pathway to propose such projects.
The settlement matters because utilities like Xcel cannot simply buy novel hardware on a whim. Every major procurement must survive regulatory review, and commissioners weigh cost, reliability, and rate impact before approving new resource additions. By explicitly authorizing Xcel to procure and integrate large clean resources, Minnesota regulators removed a procedural barrier that might otherwise delay deployment by years. The state’s electric rate case process will ultimately determine how the costs of such investments flow through to ratepayers, a tension that is far from resolved. Docket schedules, testimony filings, and commission orders posted by the Minnesota Public Utilities Commission will shape how much long-duration storage utilities can build, how quickly they can deploy it, and who bears the financial risk if performance or market conditions diverge from expectations.
Cost Tensions and the Road Ahead
The central tension in this story is not technical but economic. Iron-air batteries use cheap, widely available materials, which should translate to lower per-kilowatt-hour costs over long discharge periods compared to lithium-ion. But the technology is still early in its manufacturing learning curve. First-generation production lines typically carry higher unit costs than mature factories, and those costs must be recovered somewhere, either through premium pricing to corporate buyers like Google or through regulated utility rates paid by households and businesses. Regulators will scrutinize whether long-duration storage can compete with alternatives such as transmission upgrades, demand response, or flexible gas plants when evaluated on a system-wide cost basis.
For iron-air storage to move from niche to mainstream, several pieces must align. Form Energy has to prove that its Weirton plant can scale production reliably and that fielded systems deliver the promised 100-hour performance with predictable operating costs. Corporate buyers must continue to value resilience and decarbonization enough to sign long-term contracts that justify factory expansion. And state regulators, following examples emerging in places like Minnesota, will need to craft rules that reward the unique capabilities of multi-day storage without saddling ratepayers with undue risk. If those conditions come together, the Weirton factory could mark the beginning of a new era in grid planning, in which iron-based batteries help bridge the gap between intermittent renewables and the always-on power that modern digital economies demand.
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*This article was researched with the help of AI, with human editors creating the final content.
