Technology giant Google has announced plans to construct a data center in Minnesota powered by a vast clean energy infrastructure, including what could become the world’s largest battery. The facility will be located in Pine Island, roughly an hour southeast of Minneapolis, marking Google’s first data center investment in the state.
The project will draw energy from 1.4 gigawatts of wind and 200 megawatts of solar power supplied in partnership with Xcel Energy, a utility known for integrating renewable generation into regional grids.
At the heart of the initiative is a 300 megawatt long duration battery developed by Form Energy, a startup specialising in iron air energy storage technology. The battery will offer 30 gigawatt hours of storage capacity and is designed to deliver power for up to 100 hours, a capability far exceeding the shorter discharge periods typical of conventional lithium ion systems. Such long duration storage allows renewable energy to remain available during nights or periods of low generation, effectively firming the grid and reducing reliance on fossil fuel backup.
Form Energy’s iron air technology operates by using oxygen to rust pebbles of iron inside the battery, generating electricity in the process. When charging, electrical current reverses the reaction, removing oxygen and restoring the iron to its metallic state. Although the chemistry is less energy efficient than lithium ion batteries, with efficiency rates between 50 and 70 percent, its low production cost offers a significant advantage. The company claims storage costs as low as 20 dollars per kilowatt hour, at least three times cheaper than lithium ion alternatives.
The Minnesota project also introduces a novel utility tariff arrangement designed to encourage investment in clean technologies without burdening ordinary ratepayers. Under the agreement between Google and Xcel Energy, the tech company will pay a premium fee structure that allows the utility to pursue innovative projects while insulating traditional customers from financial risk. Similar arrangements have been tested in other jurisdictions, reflecting a growing trend in which major technology firms collaborate with utilities to accelerate decarbonisation and grid modernisation.
Long duration storage projects remain experimental but increasingly central to the future of renewable energy systems. The first deployment of Form Energy’s technology is already underway with cooperative utility Great River Energy, which is installing a smaller 150 megawatt hour system capable of delivering 1.5 megawatts over 100 hours.
If successful, such projects could reshape energy markets by enabling utilities to store surplus renewable power and deploy it when needed, reducing dependence on fossil fuels and strengthening grid resilience. Google’s Minnesota investment signals confidence in this emerging technology and underscores the expanding intersection of data infrastructure and clean energy innovation.