State regulators approve Xcel Energy's plan for battery storage in Becker

Iron-air battery system is seen
An artist’s rendering of a 56-megawatt iron-air battery system, developed by Boston-based Form Energy. Xcel Energy is planning to install a 10-megawatt battery system in Becker, Minn., where it’s building a large solar project.
Courtesy of Form Energy

State regulators on Thursday gave Xcel Energy a green light to test a battery system to store electricity in Becker.  

The Minnesota Public Utilities Commission unanimously approved the project, which Xcel expects will begin operating in late 2025.

The Minneapolis-based utility is partnering with Massachusetts-based Form Energy on the project, next to its Sherco coal-fired power plant. Xcel plans to retire the plant over the next seven years, and is building a large solar project on the site.

Form Energy's iron-air battery can store electricity for 100 hours, much longer than the four hours of a lithium-ion battery. 

Create a More Connected Minnesota

MPR News is your trusted resource for the news you need. With your support, MPR News brings accessible, courageous journalism and authentic conversation to everyone - free of paywalls and barriers. Your gift makes a difference.

Xcel says the battery could help it manage energy demand, especially when solar and wind farms aren't producing power, as it moves to replace fossil fuels with renewable energy sources that don’t generate greenhouse gases.

Xcel attorney Ian Dobson told the commission that the project will test the capability of the battery, and is expected to create 15 to 20 construction jobs. It could provide insight on how battery storage systems could be located at other renewable energy facilities, he said.

“We think that this is a project that's going to help Becker. It's going to help us, and it's going to help us learn quite a bit,” Dobson said. 

Environmental groups, including the Sierra Club and the Union of Concerned Scientists, submitted comments in support of the project.

But the state attorney general's office raised concerns about the cost — which Xcel isn't publicly disclosing — and the impact on Xcel customers’ electric bills. The PUC didn’t require Xcel to reveal the number.

Dobson said Xcel considers the cost a trade secret. He did say residential customers will pay an average of less than 30 cents a month over the project’s 10-year life span.

Bill Gates' company, Breakthrough Energy, has committed to a $10 million grant for the project. Xcel is also pursuing funding from the U.S. Department of Commerce, Dobson said.

A generating station
The coal-powered Sherburne County Generating Station in Becker, Minn.
Tim Evans for MPR News