Form Energy has signed an agreement to supply 12 gigawatt-hours of iron-air batteries to Crusoe, the AI infrastructure company. Announced at CERAWeek in Houston on March 24, the deal is the largest energy storage contract specifically targeting AI data centers to date and pushes Form Energy's total pipeline past 75 GWh. Days later, Michigan's utility regulator approved 1,332 MW of battery storage contracts in a single session, including three projects dedicated to a new data center. Together, the announcements show how quickly data center demand is reshaping the grid storage market. Form Energy manufactures its iron-air battery systems at Form Factory 1 in Weirton, West Virginia, with all Crusoe units to be built domestically. Why AI Data Centers Are Turning to Multi-Day Storage The problem is straightforward: building a hyperscale AI campus capable of running thousands of GPUs requires hundreds of megawatts of reliable power, and grid connections at that scale take years to permit and construct. The U.S. government has acknowledged the bottleneck by encouraging "bring your own capacity" (BYOC) models, where data center developers provide their own power supply rather than queuing for a utility tie-in. Crusoe, which operates AI compute facilities with a focus on speed-to-power, has embraced that approach directly. The company's co-founder and CSO Cully Cavness stated at CERAWeek: "The future of AI depends on access to abundant, reliable power delivered at speed. Solutions like these batteries can solve those crunch moments to enable more power to be available for the rest of the year." Under the deal, Crusoe secures reserved volume, fixed pricing, and committed delivery schedules starting in 2027. Form Energy's CEO Mateo Jaramillo framed the partnership around domestic manufacturing: "This partnership with Crusoe demonstrates how multi-day energy storage can unlock new capacity for data centers while strengthening domestic manufacturing." All systems will be built at Form Factory 1 in Weirton, West Virginia, which began production in 2026. Crusoe builds AI compute facilities designed to operate independently of grid constraints, using on-site energy generation and storage. How Iron-Air Batteries Work — and Why the Tradeoffs Matter Iron-air batteries are fundamentally different from the lithium-ion systems that dominate grid storage today. During discharge, iron pellets react with oxygen from ambient air to form iron oxide, releasing electrons. During charging, applied current reverses the reaction, reducing iron oxide back to metallic iron. The raw materials — iron, water, and air — are among the most abundant on Earth. The tradeoff is round-trip efficiency. Lithium-ion BESS systems typically achieve 85-92% round-trip efficiency. Iron-air batteries come in considerably lower. Form Energy has been transparent about this since emerging from stealth in 2021, and argues that iron-air is not competing with lithium-ion on the same use cases. For applications where power is needed over 100 hours or more — covering multi-day lulls in renewable output, or backing up a data center through a period of grid unavailability — the lower efficiency matters less than the cost per kilowatt-hour of storage capacity, where iron-air has a claimed advantage of 10x or more over lithium. Iron-air cells use iron pellets as the anode and ambient air as the cathode, with no lithium or cobalt required. A Pipeline That Keeps Growing The Crusoe deal is Form Energy's third major announced agreement in 2026. Earlier this month, the company disclosed a 30 GWh iron-air battery agreement tied to a Google-Xcel Energy data center project in Minnesota — the largest single energy storage contract ever announced by watt-hour capacity. Weeks before that, Form signed its first international deal: a 1 GWh system for FuturEnergy Ireland. The Crusoe contract adds 12 GWh more, pushing the total disclosed pipeline past 75 GWh. Whether all that pipeline converts to hardware is the real question. Form Energy is still scaling its factory and has acknowledged it needs further cost reductions through its second-generation system design. Crusoe is hedging as well — in parallel with the Form Energy deal, it also struck an arrangement with Redwood Materials for second-life battery modules in modular data centers, a different approach using recycled lithium packs. Still, the pace of Form Energy's announcements is notable. In five years, the company has gone from a stealth startup backed by Bill Gates and other climate investors to the supplier behind the largest energy storage contract in history and now the anchor tenant for Crusoe's power strategy. The question is how fast Form Factory 1 can ramp, and when a second factory comes online. Michigan's PSC approved six battery storage projects totaling 1,332 MW on March 27, with three sites dedicated to serving a new 1,383 MW data center in Washtenaw County. Michigan Approves 1,332 MW of Battery Storage in a Single Day Three days after the Crusoe deal was announced, Michigan's Public Service Commission approved six battery energy storage contracts totaling 1,332 MW on March 27 — the largest single-day storage approval in the state's history. The projects span DTE Electric's service territory and address two distinct needs. The first three projects fulfill DTE Electric's 2023 integrated resource plan, which called for at least 850 MW of battery storage alongside 15,000 MW of new solar and wind capacity: the 450 MW Big Mitten Energy Center in Huron County (a 20-year tolling agreement), the 350 MW Monroe I Energy Center, and the 200 MW Fermi Energy Center, both self-build contracts in Monroe County. The remaining three projects — Fish Creek (132 MW), Cold Creek (100 MW), and Pine River (100 MW) — are directly tied to a 1,383 MW data center being developed by Green Chile Ventures in Washtenaw County's Saline Township. The MPSC approved the data center project in December 2025, imposing safeguards to prevent residential ratepayers from subsidizing the facility's costs. Last week's battery approvals cover the first 332 MW of what the commission expects will grow to 1,383 MW of dedicated storage, all funded by the data center developer rather than the general customer base. The Michigan model is notable: rather than treating storage as a shared grid benefit and spreading costs across all ratepayers, regulators are structuring dedicated contracts that tie specific battery capacity to specific large industrial customers. Other states managing their own data center pipeline queues are likely watching the approach closely. What This Means for the Battery Storage Industry The convergence of AI data center demand with grid storage is creating a new customer segment that operates differently from utilities and independent power producers. Tech companies have capital, urgency, and regulatory pressure to secure their own power, and they want reliability that grid-tied systems cannot always guarantee. That opens space for technologies — iron-air, flow batteries, second-life lithium packs — that solve longer-duration problems at lower cost per kilowatt-hour, even at the expense of round-trip efficiency. U.S. BESS deployments hit a record 57.6 GWh in 2025 and are projected to reach 70 GWh in 2026, with most of that growth driven by lithium-ion grid projects. The data center-specific demand layer on top of that is still relatively new, and it is big enough to be a category in its own right. Form Energy's pipeline of 75 GWh — most of it announced in the past three months — is a signal that at least some of that demand is starting to crystallize into contracts. Whether iron-air can scale fast enough before lithium-ion costs drop further is the race the industry will be tracking over the next 18 months. For now, the fact that a five-year-old startup manufacturing an entirely new battery chemistry is landing 12 GWh deals at CERAWeek says something about how much the energy storag