Old West Virginia Steel Mill Becomes a Green-Energy Powerhouse

Form Energy’s rust-powered batteries are critical piece of clean-energy puzzle

For decades, iron ore was shipped into a sprawling steel mill on the banks of the Ohio River near Pittsburgh. Iron deliveries will resume soon at the 55-acre site, this time as a key ingredient in batteries fueled by green energy.

Instead of being turned into steel, the iron rusts when exposed to oxygen. The chemical reaction discharges electricity that can power homes and businesses for 100 consecutive hours, according to the company.

When these iron batteries are tapped out, they will be recharged with renewable power, turning the rust back into iron. The batteries are designed to absorb large amounts of electricity when the sun is shining and the wind is blowing, adding resiliency to power grids.

Form Energy will produce so-called long-duration batteries that are a critical piece of the clean-energy puzzle.

More than $58 billion was invested in long-duration batteries worldwide between 2020 and 2022, according to Wood Mackenzie. The Biden administration appropriated $505 million for the development of long-duration storage in the 2021 infrastructure law, and last year’s Inflation Reduction Act contains substantial tax credits for long-duration battery projects.

“As we get more and more renewables, we need longer and longer durations, and that’s when long-duration storage comes in,” said Susan Babinec, leader of stationary battery storage research at Argonne National Laboratory.

There are many kinds of long-duration storage technologies, which the Energy Department defines as 10 to 160 hours of energy discharge. Thermal storage uses renewable energy to heat bricks, rocks or molten salt and release the energy later to make electricity. Less high-tech but equally effective is pumping water up a hill and letting it flow down to generate electricity.

Form’s batteries deploy an electrochemical reaction that turns iron into rust and back again.

Big money is behind Form’s 400,000-square foot factory, its first full-scale plant, which is expected to double in size by 2025. Backers include Breakthrough Energy Ventures, a climate investment fund whose investors include Microsoft’s Bill Gates and Amazon.com’s Jeff Bezos. Last year, Form raised $450 million to build the facility from investors including TPG Rise Climate and steelmaker ArcelorMittal, which once owned the Weirton steel mill.

Form Energy co-founder and Chief Executive Mateo Jaramillo, who ran a battery division at Tesla and developed its Powerwall battery, recently moved to Pittsburgh from San Francisco. “This is precisely why you start a company,” he said. “To make things and make sure you do it at scale. It’s great to be at this stage.”

Another founder is Yet-Ming Chiang, an engineering professor at Massachusetts Institute of Technology and co-founder of battery pioneer A123 Systems. The goal at Form Energy was to develop batteries that were cheap, didn’t catch fire, didn’t need scarce and costly metals like cobalt and lithium, and could produce electricity for a long time.

Form Energy landed on iron, which is plentiful, cheap and nonflammable. That allows the company to build hefty battery modules the size of a washer-dryer set. Packed together in enclosures resembling shipping containers, the batteries can discharge power for about four straight days—far longer than the standard four-hour discharge capability of lithium-ion batteries.

Each battery contains roughly 50 one-meter-tall cells made up of iron and air electrodes that enable the reactions that store and discharge electricity. The battery takes in oxygen and converts iron to rust. The process produces electricity. When electricity is plentiful, it is used to reverse the process and turn rust back into iron, releasing oxygen.

A one-megawatt system can take up about half an acre of land, according to Form. The company says its batteries can store energy at less than one-tenth the cost of lithium-ion battery technology.

Weirton’s tumbledown steel mill once provided work for more than 10,000 people before the plant stopped producing steel in the mid-2000s. The tiny town of about 18,000 people sits astride the former mill, whose defunct pipes and cables snake among its streets and buildings. The mill at its peak had four blast furnaces that could produce thousands of tons of steel a day.

The $760 million battery factory rising from the mill’s ashes will employ about 750 workers once completed, providing a mean salary of $63,000. Still, it represents a blooming industrial transformation in Appalachia and elsewhere in the U.S. fueled by the Biden administration’s Inflation Reduction Act, the 2021 infrastructure act and last year’s Chips Act.

Jaramillo said the passing of the Inflation Reduction Act made it clear that the entire electric industry was shifting into high gear. Form Energy has been able to move faster and at a greater scale as utilities line up to use its batteries, he said.

As of mid-July, more than 270 clean-energy projects have been announced in the U.S., with investments totaling $130 billion, since the Inflation Reduction Act was passed, according to Bank of America. Spending on manufacturing construction has doubled since late 2021, according to the bank. Manufacturing employment in the U.S., has reached its highest level since 2008, according to the Federal Reserve Bank of St. Louis.

Much of that infrastructure spending is coming to Republican-led states such as West Virginia. Down the Ohio River from Weirton, in Ravenstown, W.Va., a company owned by Warren Buffett’s Berkshire Hathaway is constructing a titanium factory that will be powered by a giant solar and battery microgrid. The project will also produce rechargeable batteries made by Our Next Energy, a Michigan energy-storage company.

Form Energy, which is based in Somerville, Mass., is in talks with utilities across the U.S., according to Jaramillo. Earlier this year, Form Energy agreed to provide a battery system to Southern Co.’s Georgia Power utility, which is expected to come online as early as 2026, subject to regulatory approval. The project will have the ability to power between 6,000 and 13,000 homes for several days. The company is also providing batteries to Xcel Energy and Minnesota’s Great River Energy.