After a year of public opposition, the controversial Midwater Energy Storage Project near the Shell Rock River has received final approval from the Minnesota Public Utilities Commission (MPUC).
The commission approved a site permit for the 150-megawatt, 600-megawatt-hour standalone battery energy storage system (BESS) in Freeborn County, Minnesota, upstream of Butler County communities along the Shell Rock River, allowing Spearmint Energy to move forward with the project despite earlier recommendations from a judge that the permit be denied.
The project was first proposed in 2024 as a large-scale BESS near Glenville, Minnesota. The facility is designed to store excess electricity generated by renewable energy sources such as wind and solar and release that power back to the electrical grid during periods of high demand.
The proposal quickly drew opposition from residents, environmental groups and local governments in both Minnesota and Iowa because of its proximity to the Shell Rock River, wetlands and shallow groundwater. Critics argued a battery fire, chemical leak or contaminated stormwater runoff could threaten water quality, wildlife habitat and downstream communities that rely on the river for recreation and conservation.
The concerns extended into Iowa, where the Butler County Board of Supervisors approved a resolution urging Minnesota regulators to deny the project, citing fears that any contamination event upstream could affect communities along the Shell Rock River watershed.
Ruth Saulsbury Clarksville city council member said, "While I am very disappointed with this decision, I am also very thankful to the many residents, local officials, organizations and neighboring communities who participated in the process by attending meetings, submitting comments, sharing information and advocating for protection of our Shell Rock River watershed."
Saulsbury had been an instrumental advocate for Iowa residents along the river. She conducted research, led campaigns to inform the public, met with activists,citizens and officials in Freeborn County, MN and petitioned supervisors in Butler County to take action.
Earlier this year, Administrative Law Judge Megan J. McKenzie issued an 89-page recommendations report concluding the project should not receive either a site permit or a transmission route permit. Her recommendation cited concerns raised throughout the review process regarding environmental risks, emergency response capabilities, stormwater management and the project's location adjacent to the Shell Rock River.
Although the judge's recommendation carried significant weight, it was advisory rather than binding. The final decision rested with the MPUC, which voted to approve the site permit.
In announcing the decision Thursday, Spearmint Energy called the approval "a significant milestone" for the project and said it advances the company's efforts to improve energy resilience throughout the Midcontinent Independent System Operator, or MISO, electrical grid.
According to the company, Midwater will occupy between 10 and 20 acres of privately owned land adjacent to the Glenworth Substation along Minnesota Highway 65 in Freeborn County.
"We appreciate the commitment of the Minnesota Public Utilities Commission and staff in reviewing this critical infrastructure project," Spearmint Energy Founder, President and CEO Andrew Waranch said in a news release. "The Midwater site permit represents a meaningful investment in Southern Minnesota's energy future."
The commission's decision concludes a closely watched permitting process that generated extensive public testimony and environmental review, though opposition from local residents and downstream communities centered on the Shell Rock River watershed is expected to continue as the project moves toward construction.
"My focus now shifts toward understanding the Commission’s written order, reviewing the permit conditions and ensuring those conditions are fully followed throughout construction and operation," Saulsbury said.
