Minnesota OKs first large-scale battery plant, taking another step toward carbon-free goal

Energy regulators approved the largest battery facility yet for Minnesota, a necessary step to reach the state’s 2040 no-carbon goals.

The $214 million project also is the first standalone battery facility in Minnesota, connecting directly to the electricity grid instead of to a power plant.

It will collect surplus energy from the grid and release it when demand spikes, helping even out electricity distribution as Minnesota depends on more wind and solar energy.

“This project represents a crucial evolution in our state’s energy infrastructure,” Public Utilities Commissioner John Tuma said in a news release.

The 150-megawatt Snowshoe Energy Storage Project will be built on a 23-acre site west of Rochester in Olmsted County. It will store enough energy to provide electricity for around 100,000 households for up to four hours.

The PUC previously has permitted batteries with solar projects, but never a standalone facility.

Florida-based owner Spearmint Energy said it will be operational in late 2027.

The batteries address the biggest challenge of shifting to weather-dependent solar or wind power: maintaining a reliable, around-the-clock energy supply.

Gregg Mast, the executive director of Clean Energy Economy MN, said standalone battery storage is critical to balancing out that fluctuation.

Energy storage projects are still limited, and most utility efforts are smaller in scale or at the pilot stage. But the Spearmint site is the first in what is expected to be a wave of battery deployments.

“We are seeing a lot of those trends for pairing battery storage with solar, for example,” Mast said. “And that is another trend that we would anticipate will continue to grow despite some of the federal headwinds when it comes to the energy transition.”

The project is not associated with a particular utility, meaning it is “the merchant market” off the grid. Therefore, it is likely to serve the short-term energy needs of utilities and cooperatives during peak demand times, according to a July report from Administrative Law Judge Kimberly Middendorf, who reviewed the case.

“The proposed project is expected to contribute to Minnesota’s transition to a carbon-free electricity supply by allowing wind and solar projects to continue to produce energy when they would otherwise be curtailed due to low demand,” Middendorf said.

One of the project’s next steps is to obtain approval to connect to the multistate grid. That approval is expected in early 2026.

After public feedback, the PUC did add some requirements for Snowshoe to work with local governments and emergency responders on safety measures, including specialized emergency equipment, a water main extension report and training. These steps would be funded by the developer.

The concerns stem partly from a fire at the largest battery-storage facility in California, which caused public health issues.