Google & Xcel Build World's Largest Grid Battery

A battery the size of a small power plant is coming to Minnesota, and it could change how we think about renewable energy storage.

Google and Xcel Energy announced plans to build the world's largest battery by energy capacity. The 300 MW system will store enough electricity to power thousands of homes for up to 100 hours, solving one of clean energy's biggest challenges: what to do when the sun isn't shining and the wind isn't blowing.

The battery uses iron-air chemistry from Form Energy, a technology that's cheaper and longer-lasting than traditional lithium batteries. Unlike the batteries in your phone or car, these iron-air modules look like "very large brake pads" and can discharge power for days instead of hours.

The project will support a new Google data center about 70 miles southeast of Minneapolis. Google is paying for the entire buildout, which includes 1,400 MW of wind power and 200 MW of solar alongside the battery system.

Xcel Energy plans to connect the battery to its Upper Midwest grid rather than installing it directly at Google's facility. That means the stored energy will benefit everyone on the grid, not just one customer.

"This is really the scale of project that we expect to bid and participate in going forward," said Mateo Jaramillo, Form Energy's CEO. His company expects to ship the first modules by the end of 2028 from its factory in West Virginia, built on the site of a former steel mill.

The timing couldn't be better. Minnesota winters can bring several consecutive days of cloudy weather with little wind, exactly when renewable energy needs backup power the most. This battery system will bridge those gaps without burning fossil fuels.

Form Energy has already been building up to this moment. Over the past two years, the company has produced more than 100,000 electrodes and tens of thousands of cells at its West Virginia facility to prove it can manufacture at scale.

Google is also contributing $50 million to Xcel's Capacity*Connect program, which will install smaller batteries throughout the grid to reduce congestion and delay expensive infrastructure upgrades. The program aims to place 50 to 200 MW of batteries in strategic locations by 2028.

The Ripple Effect

This partnership shows how tech companies hungry for clean power can actually accelerate the renewable energy transition for everyone. Google gets reliable electricity for its data center, Xcel gets cutting-edge storage technology, and Minnesota ratepayers get a more stable grid powered by clean energy.

The project also breathes new life into manufacturing communities. Form Energy's West Virginia factory sits where a steel mill once stood, creating jobs in the clean energy economy where heavy industry used to thrive.

When this battery comes online, it won't just be the world's largest—it'll prove that renewable energy can work even during the toughest conditions.