The Minnesota Public Utilities Commission has approved the site permit for Spearmint Energy's 150 MW / 600 MWh Midwater Battery Energy Storage System in Freeborn County. The standalone project advances grid resilience in the MISO market and becomes the company's second permitted battery storage project in Minnesota.
Spearmint Energy is expanding its footprint in the MISO (Midcontinent Independent System Operator) market with a newly approved 600 MWh standalone storage project in Southern Minnesota. The Minnesota Public Utilities Commission (PUC) has officially granted a Site Permit for the 150 MW / 600 MWh Midwater Energy Storage Project in Freeborn County. Sited next to the Glenworth Substation off Minnesota Highway 65, the four-hour BESS is designed to capture surplus renewable generation during off-peak hours and discharge power back into the grid during peak demand. Following the company's pioneering Snowshoe Energy Storage Project, Midwater solidifies Spearmint’s position as a leading developer of flexible grid infrastructure in the Midwest.
Built as a four-hour battery energy storage site, the project will use up excess energy produced during times of low demand and release that energy when there is a need for more electricity. In addition to increasing the reliability of the electricity system and helping to stabilize it, this type of flexibility in operation makes the electricity production process more affordable.
The project also strengthens Minnesota's growing battery energy storage portfolio as utilities and grid operators continue integrating larger volumes of renewable energy generation. Battery storage plays an increasingly important role in balancing variable solar and wind resources while providing fast-response grid services.
Midwater is Spearmint Energy's second battery storage project to secure state permitting approval in Minnesota. The current approval comes after the company’s successful Snowshoe Energy Storage Project in Olmsted County, which has become the first standalone battery energy storage project approved for regulatory compliance in the state.
According to the company, the permit is a step forward for the company's efforts to grow its development portfolio in the MISO area, in view of growing electricity consumption in the region and the need for more flexible grid infrastructure to ensure reliable electricity transmission. Large-scale projects for energy storage like Midwater are likely to mitigate grid congestion, increase energy availability during the period of peak electricity demand and contribute to the shift towards the use of clean electricity sources.
With the permit for the site received, Spearmint Energy is expected to move on with the development of the project, through engineering design, financing and ultimately its construction. Upon completion, the Midwater energy storage project will provide the state's electricity grid with extra energy storage capability.