Power Co-op Evaluating Development of Pumped Storage Hydropower at Closed Mines


 Dairyland Power Cooperative is collaborating with Mine Storage International AB (Mine Storage) and Michigan Technological University to explore the potential for pumped underground storage hydropower in the Upper Midwest.  

With input from Michigan Tech and Mine Storage, Dairyland will evaluate closed mines in the region for the development of pumped hydro energy storage, an opportunity that supports grid reliability and renewable energy generation while repurposing retired industrial sites in an innovative way.

“Pumped hydro is an exciting opportunity for Dairyland as part of our commitment to adopting viable new storage technologies that support the clean energy transition,” said Dairyland President and CEO Brent Ridge. “The Mine Storage system brings unique benefits as it essentially recycles existing but unused sites into flexible, carbon-free power storage systems without some of the environmental concerns of traditional battery storage.” 

Pumped storage hydropower systems use upper and lower reservoirs to move water through turbines, generating and storing energy that is capable of being released on demand in response to consumer needs. In recent years, research on underground pumped storage hydropower systems has validated it as a practical solution to accessible, affordable and sustainable energy. 

“The American market for energy storage is growing quickly,” said Mine Storage CEO Thomas Johansson. “We view Dairyland as a forward-thinking utility with an attractive location and a portfolio of energy resources. Dairyland also has a business strategy and corporate culture which makes a collaborative partnership ideal for us at Mine Storage when entering the U.S. market.” 

Michigan Tech will serve as a technical resource as Dairyland explores potential development options. The University has led significant research and reporting on the potential of regional pumped underground storage hydro (PUSH) systems in closed hard-rock metal mines through the work of Tech’s Keweenaw Energy Transition Lab (KETL). 

“We are excited about working with Dairyland and Mine Storage to make this transformative technological application a reality. This collaboration is a true testament to the effort and creativity that PUSH researchers — faculty and students — put into solving one of the most difficult challenges of our time,” said PUSH project leader and energy policy expert Roman Sidortsov, an associate professor at MTU. 

PUSH researcher and industrial archaeology expert Timothy Scarlett said the team’s shared vision is that the energy transition is an opportunity. “We can change post-mining liabilities into essential assets that address local concerns while solving problems for the entire grid,” said the MTU associate professor of archaeology and anthropology. “These are complex problems for which we’ve found solutions that are both smart and elegant.” 

Mine Storage, based in Stockholm, Sweden, develops abandoned mines into pumped hydro energy storage, creating a flexible resource similar to utility-scale battery storage. Rather than drawing water from an outside source, the system uses resources within the mine.

Headquartered in La Crosse, Wisconsin, Dairyland provides wholesale electricity to 24 member distribution cooperatives and 27 municipal utilities. A Touchstone Energy Cooperative, Dairyland’s service area encompasses 62 counties in Wisconsin, Minnesota, Iowa and Illinois. 

Michigan Technological University is a public research university founded in 1885 in Houghton, Michigan, and is home to more than 7,000 students from 55 countries around the world. Consistently ranked among the best universities in the country for return on investment, Michigan’s flagship technological university offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, computing, forestry, business and economics, health professions, humanities, mathematics, social sciences, and the arts. The rural campus is situated just miles from Lake Superior in Michigan's Upper Peninsula, offering year-round opportunities for outdoor adventure.