World’s first grid iron-air battery goes live in Delft
The iron-air battery can store energy for up to 4 days, at just one-tenth the cost of lithium-ion batteries.
Published on July 31, 2025

© Ore Energy
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Ore Energy, a Dutch startup, has made history by installing the first-ever grid-connected iron-air battery system in Delft. This technology can store energy for up to 4 days, at just one-tenth the cost of lithium-ion batteries, without using rare materials like lithium or cobalt. Ore's iron-air battery addresses critical grid challenges, reducing curtailment, replacing fossil fuel backup, and enabling more affordable and reliable renewable power.
The innovative iron-air battery from Ore Energy leverages a straightforward yet ingenious chemical reaction: rusting and unrusting. During discharge, metallic iron undergoes oxidation, essentially rusting, which releases electrons and generates an electrical current. Conversely, during charging, an electrical current reverses the process, converting the rust back into metallic iron. This process occurs on the iron side of the battery, requiring the presence of air (oxygen) at the air electrode. A water-based electrolyte—a substance that conducts electricity—facilitates the movement of electrical charges, specifically hydroxyl ions, between the anode and cathode—the positive and negative battery electrodes. The whole system is designed with a scalable modular approach, allowing the construction of plug-and-play energy storage systems ranging from megawatt-hour (MWh) to gigawatt-hour (GWh) scales.
Iron-air battery proves Europe's value
Ore Energy, established in 2023 as a spin-out from TU Delft, is behind this groundbreaking achievement. The company's CEO and co-founder, Aytaç Yilmaz, stated: "This achievement is proof that Europe can lead the world in energy innovation and energy resilience. We've shown that breakthrough solutions like iron-air can move from lab to grid in just two years and can be built entirely with a European supply chain. Our battery doesn't just store clean energy, it solves three of the grid's biggest problems: it slashes curtailment, replaces fossil backup, and reduces the need to overbuild wind and solar. Long-duration storage like ours is what makes renewable power reliable, affordable, and sovereign. And now it's ready."
The iron-air battery system is deployed at The Green Village, a testing ground at the Delft University of Technology for pioneering climate and energy innovations. Lidewij van Trigt, Energy Transition Project Manager at The Green Village, highlighted the significance of this installation. "Connecting the first grid-ready iron-air system here in Delft shows what's possible when research, regulation, and industry align. We're proud to provide a proving ground for technologies that will shape the future of Europe's energy system," she said.
The company plans to achieve full GWh-range production capacity by 2030.