Category: Technology | Published: 2026-03-05
The World's Largest Battery System
Google has announced plans to build the world's largest battery storage system at its new data centre in Pine Island, Minnesota. The project, valued at close to one billion dollars, will use iron-air battery technology developed by Form Energy to deliver 100 continuous hours of backup power - more than four days of uninterrupted supply.
The system represents a step change in how large-scale data centres are powered, moving away from traditional fossil fuel backup generators towards long-duration clean energy storage.
How Iron-Air Batteries Work
Unlike the lithium-ion batteries found in phones, laptops and electric vehicles, iron-air batteries use a fundamentally different chemistry based on the reversible rusting of iron.
During discharge, oxygen is drawn into the battery cells, causing the iron to oxidise (rust) and release electrical energy. During charging, the process reverses - the rust is converted back to iron, and the oxygen is released. The raw materials are abundant and inexpensive, which gives iron-air technology a significant cost advantage.