Form Energy Secures $750M to Scale 100-Hour Iron-Air Batteries for Google and the Grid

TL;DR

• Form Energy has raised $750 million in new funding to scale manufacturing of its 100-hour iron-air battery, with backing tied to major new customers Google and Crusoe.
• The capital will accelerate production at its West Virginia factory and bring its low-cost, iron-based long-duration storage technology to commercial scale.
• The deal highlights how multi-day storage is becoming critical for both decarbonizing the grid and powering energy-hungry AI data centers with reliable clean energy.

A Massive Infusion for Multi-Day Storage

Form Energy has closed a landmark $750 million funding round to bring its long-duration energy storage from pilot to mass production. The Somerville, Massachusetts-based company said the new capital will dramatically expand manufacturing capacity for its iron-air battery system, which can deliver electricity for 100 hours straight — far beyond the 4-hour duration of conventional lithium-ion installations.

The round marks one of the largest investments ever made in long-duration storage and signals growing confidence from both climate-tech investors and Big Tech that the technology is ready for prime time. While existing investors including Breakthrough Energy Ventures, ArcelorMittal, and TPG Rise have long backed the company, the latest raise is notable for who is buying the batteries, not just who is funding them.

Why 100 Hours Changes Everything

For years, the clean energy transition has faced a stubborn problem: what happens when the sun doesn't shine and the wind doesn't blow for days at a time? Solar and lithium-ion batteries handle daily cycles well, but they can't cover extended weather events, seasonal lulls, or prolonged grid stress — the so-called Dunkelflaute.

Form Energy's system is designed to solve that exact gap. Instead of storing energy for hours, it stores it for days. That capability allows a grid dominated by renewables to ride through multi-day periods of low generation without firing up fossil fuel peaker plants. Analysts have long called this kind of 100+ hour storage the missing link for a truly reliable, deeply decarbonized grid, and utilities are now starting to procure it as a cost-effective alternative to natural gas.

Inside the Iron-Air Breakthrough

The secret to Form's approach is its radical simplicity. Its battery works on the principle of reversible rusting. When discharging, the battery breathes in oxygen from the air and converts iron metal to iron oxide — rust — releasing energy. When charging, electrical current reverses the process, converting the rust back to iron and expelling oxygen.

The materials — iron, water, and air — are among the cheapest and most abundant on Earth. That gives Form a decisive cost advantage over lithium-ion, which relies on expensive, geopolitically sensitive minerals like lithium, cobalt, and nickel. The company has targeted a system cost of under $20 per kilowatt-hour, less than one-tenth the cost of lithium-ion, making multi-day storage economically viable for the first time.

From Weirton to Gigawatts: Scaling Manufacturing

The bulk of the $750 million will go toward scaling Form Factory 1 in Weirton, West Virginia. The former steel mill town on the Ohio River is now home to Form's first high-volume manufacturing plant, where the company began initial production of its battery enclosures and iron anode components last year.

With the new funding, Form plans to accelerate hiring, automate production lines, and ramp to gigawatt-scale annual output. The expansion is expected to create hundreds of additional manufacturing jobs in the region and establish a domestic supply chain for long-duration storage at a time when onshoring clean energy manufacturing has become a national priority. The company has also indicated the capital will support development of future factories to meet a growing pipeline of utility orders.

Why Google and Crusoe Are Buying In

The most telling part of the announcement is the customer list. Google and Crusoe, the AI infrastructure company, have both signed on as new customers, underscoring a powerful new driver for long-duration storage: data centers.

Google, which has committed to operating on 24/7 carbon-free energy by 2030, sees Form's 100-hour batteries as a way to firm up its wind and solar portfolio and keep its data centers running on clean power through extended periods of low renewable output. For Crusoe, which builds and operates AI-focused data centers often co-located with energy sources, the batteries offer a way to deliver the round-the-clock reliability that AI workloads demand without relying on gas backup.

Their involvement shows that long-duration storage is no longer just a utility play. As AI drives unprecedented electricity demand — with some forecasts projecting data centers could consume up to 12% of U.S. electricity by 2028 — tech companies are directly investing in the next generation of grid hardware to ensure their growth is both powered and sustainable.

The Missing Link for AI and the Clean Grid

The convergence of two megatrends — grid decarbonization and the AI boom — has put Form Energy in a uniquely powerful position. Utilities need cheap, long-duration storage to retire coal and gas plants while maintaining reliability. At the same time, hyperscalers need massive amounts of firm clean power to meet both their climate goals and their customers' demands for always-on compute.

Iron-air batteries sit at the intersection. Unlike hydrogen or compressed air, they can be sited anywhere, have a small geographic footprint, and integrate directly with existing transmission infrastructure. Early utility customers including Great River Energy in Minnesota and Georgia Power have already contracted for Form's first commercial deployments, with the first systems expected to come online in 2026 and 2027.

What Comes Next

With $750 million in fresh capital and anchor customers in both the tech and power sectors, Form Energy is moving from a promising technology company to a commercial manufacturer. The next 18 months will be critical as the company proves it can produce its batteries at scale, at cost, and on schedule.

If it succeeds, the impact could be transformative. Cheap, 100-hour storage would not only make a wind-and-solar grid reliable enough to displace fossil fuels entirely, but also provide the firm clean energy backbone that the AI economy will need to grow sustainably. For years, long-duration storage was the technology everyone said the grid needed next. With this milestone, it may have finally arrived.

AndroGuider Team

Articles written by the AndroGuider team. We try to make them thorough and informational while being easy to read.