The Dutch startup Ore Energy just cleared a major hurdle for long-duration energy storage: completing what it says is the first iron-air battery system connected to the grid.
Iron-air batteries, known colloquially as “100-hour batteries,” charge and discharge electricity through a reversible rusting process. They can discharge energy for multiple days, versus dominant lithium-ion batteries that range between four and 12 hours.
For years, Form Energy has dominated the iron-air battery conversation, picking up $1.2 billion in venture capital as it moved closer to commercial deployment of its systems. And in most respects, Form Energy remains way ahead.
The company raised a $405 million Series F venture round in October 2024, and built out a manufacturing facility at an old steel factory in West Virginia that started production last fall. The company has a pipeline of projects that range from 100 megawatt-hours to 8,500 megawatt-hours, with several scheduled to come online later this year. Its next step is demonstrating that its commercial-scale batteries work as promised.
But Ore’s grid-connected project is an important benchmark. The iron-air storage startup, founded in 2023, plans to move fast, according to Bas Kil, who leads business development for the company.
“We are really busy talking with a lot of commercial parties about deploying our systems,” Kil said. “So that is for us really the next time. We’re not planning to do years and years of pilot-scale [projects]; we believe that our system is now ready for commercial deployment.”
Ore wants to scale to 50 gigawatt-hours per year by 2030 — an audacious goal, given the company’s size. The team currently has 30-some people, most of whom are working in research and development.
And the first battery is tiny at just less than a mega-watt hour. The full system has 4.2 megawatt-hours of capacity, and is housed in a 40-foot container; once deployed at the commercial scale, Ore will stack these modules according to the customer’s needs. The system, according to the company, is the first LDES system designed, built, and installed wholly in Europe.
The project is still just pilot-scale, deployed at The Green Village, a Delft University of Technology testbed for climate and energy technologies — that fortuitously has its own grid connection. (Ore Energy is a TU Delft spin-out, where its co-founders spent eight years studying and developing Ore’s specific technology.) That connection will allow the company to immediately begin to test multi-day energy shifting, even at this early stage.
The European grid, according to Kil, “has a big need for this technology”; this is especially true in the Netherlands, which has a relative lack of sun and abundant, though intermittent, wind.
As a result, the main market that Ore is targeting is European utilities that will be decommissioning coal- and gas-fired power plants, and looking for a way to fill the gap. (A majority of countries in Europe have pledged to transition away from coal in the coming decades.) The company is also interested in co-locating its systems directly with renewables, and especially with wind.
“The generation profile of solar matches really well with the duration of lithium-ion batteries,” Kil said. “But with wind, it’s very common to have multiple days of very high or low generation. So you could easily have three days where all your wind farms are producing at close to maximum capacity…and in your first two to four hours, all your lithium-ion batteries will be full.”
The company is simultaneously scouting locations for its first commercial factory. With the extremely simple materials required for iron-air batteries, Kil said, Ore plans to completely source its materials from within Europe. This has the potential benefits of both insulating the company from geopolitical risks, and aligning with the European Union’s Clean Industrial Deal program, which will mobilize over 100 billion euros to support EU-made clean manufacturing. The startup is already supported by the European Innovation Council, and was part of its accelerator program.
Ore raised more than $11.5 million (or 10 million euros) in seed funding, announced in 2024. In the year since, the company has secured additional subsidies and grants, largely from government entities within Europe, bringing the total closer to $23 million (or 20 million euros).
Editor’s note: This story was updated on July 30 to clarify that the pilot’s battery has a sub-megawatt-hour capacity; a previous version of the story stated incorrectly that the company is deploying one of its full-scale 4.2 MWh systems for the pilot.
