Breakthrough: world's first rust battery connected to the grid
The Delft-based start-up Ore Energy is the first in the world to connect a rust battery to the grid.
Published on August 5, 2025
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The Delft-based start-up Ore Energy is the first company to connect an iron-air battery to the public power grid. The battery uses a reversible rust reaction and is currently being tested in a realistic setting on the campus of Delft University of Technology. With a storage time of up to 100 hours, this technology is a sustainable alternative to lithium-ion batteries, without the need for rare materials.
How it works
The principle is as follows: during charging, rust (iron oxide) is converted into pure iron using electrical energy. When discharged, the iron reacts with oxygen from the air, creating rust again and releasing electricity.
Buffer for renewable energy sources
Where traditional lithium-ion batteries can usually store between two and six hours of energy, Ore Energy's iron-air battery offers a storage capacity of up to 100 hours. This makes the technology ideal as a buffer for renewable energy sources such as solar and wind, whose production varies greatly. Gas-fired power stations are currently often used for this purpose.
Scaling up
Ore Energy aims to scale up to an annual production of 50 gigawatt hours in the coming years to enable large-scale energy storage.
