Dairyland Power Cooperative is collaborating with Mine Storage International AB (Mine Storage) and Michigan Technological University (MTU) to explore the potential for pumped storage hydropower in the Upper Midwest. Dairyland will be evaluating the development of underground pumped hydro at closed mines, 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 & CEO Brent Ridge. “The Mine Storage system brings unique benefits as it essentially recycles an existing, but unused, site into a flexible, carbon-free power storage system without some of the environmental concerns of traditional battery storage.”

What is pumped storage hydropower? It is an energy storage system. Pumped hydro performs similarly to a giant battery, storing power and then releasing it on demand—typically during times of high energy use. Two water reservoirs generate power as water moves down from one to the other, passing through a turbine, before the system pumps water back into the upper reservoir.

“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.”

Mine Storage (Stockholm, Sweden) develops abandoned mines into pumped hydro energy storage, a flexible resource similar to utility-scale battery storage. Instead of needing to draw water from a river or lake, the natural resources are available and contained within a mine. Information on the Mine Storage concept is found here.

MTU (Houghton, Mich.) 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 hydro storage systems.