Xcel Energy will supply electricity to a new Google data centre in Pine Island, Minnesota, under a large clean energy agreement that also includes the world’s biggest battery system by energy capacity.
The project combines wind, solar, and a 300-megawatt iron-air battery system built by Form Energy. The goal is to power Google’s core services, including Search, YouTube, Maps, and Workspace, while keeping costs stable for existing customers.
$1 Billion battery order
Earlier this week, Google confirmed the data centre would run on a mix of 1.4 gigawatts of wind power, 200 megawatts of solar, and a long-duration battery capable of discharging for days.
According to TechCrunch, Google paid Form Energy about $1 billion for the massive 100-hour battery system, citing reporting from The Information. The system will deliver 300 megawatts of continuous electricity over 100 hours, making it the largest battery ever announced globally by energy capacity at 30 gigawatt-hours.
Form’s iron-air battery works in a unique way. Oxygen is pumped into the system, which rusts iron and releases electrons. The process can be reversed, allowing the battery to store and discharge electricity over multiple days. This helps smooth out fluctuations from wind and solar generation.
The startup has been developing the technology for years and has built a factory in West Virginia to manufacture the batteries. But until now, it had not secured a customer at this scale.
Form Energy CEO Mateo Jaramillo is raising a $500 million funding round following the Google deal. The company has already raised about $1.4 billion to date, according to PitchBook, and plans to go public next year.
Clean Energy Without Raising Customer Bills
Under the Electric Service Agreement, Google will cover all costs related to its power demand, including new grid infrastructure. Xcel Energy said existing customers will not see higher bills because of the project.
The agreement includes: 1,400 MW of wind, 200 MW of solar, 300 MW of long-duration storage, and a $50 million investment in Xcel’s Capacity*Connect Program to improve grid reliability. The additional generation will push Xcel Energy further beyond its current 70% carbon-free electricity mix.
Google says the partnership supports its push to expand AI and cloud infrastructure responsibly. Amanda Peterson Corio, head of Data Centre Energy at Google, said the company aims to integrate carbon-free energy and long-duration storage to build a more resilient system for local communities.
The 100-hour battery is especially important for AI-driven data centres, which require stable, round-the-clock electricity.
Unlike short-duration lithium-ion batteries, iron-air systems can supply power over several days, helping manage extreme demand or low renewable output. The Electric Service Agreement will now go to the Minnesota Public Utilities Commission for approval.
