Battery Storage Permits
Minnesota Has Approved Spearmint's 150 MW State Battery Storage Project
Adam Harrie — July 17, 2026
Minnesota's Public Utilities Commission approved a Site Permit for Spearmint Energy's state battery storage project, clearing the way for the 150 MW/600 MWh Midwater Energy Storage Project in Freeborn County. The standalone battery system will be sited on 10 to 20 acres adjacent to the Glenworth Substation and is designed to support grid stability and reliability across the MISO region.
Midwater marks Spearmint's second Minnesota project to advance through state permitting, following the Snowshoe Energy Storage Project in Olmsted County, the first standalone battery project approved in the state. Spearmint currently operates 350 MW/700 MWh of battery storage in ERCOT, with an additional 300 MW/600 MWh under construction nationwide.
Spearmint Energy shows how states are increasingly turning to battery storage infrastructure to balance supply and demand while integrating a more diverse mix of generation resources.
