Columbia Energy Storage Project

The Columbia Energy Storage Project was selected for an award for a cooperative agreement with the U.S. Department of Energy's Office of Clean Energy Demonstrations to support the construction of a compressed carbon dioxide (CO₂) long-duration energy storage system at the site of the Columbia Energy Center.

The innovative project would be the first of its kind in the United States. The proposed 18-megawatt project would be capable of providing at least 10 hours of energy storage.  

The added reliability and dispatchability provided by the project would help to further enable MGE's ongoing transition toward greater use of renewables. It also would help to manage long-term customer costs because projects like this one enable the partner utilities to store energy to help meet peak demand.  

The project would use a closed-loop process either to create electricity or to store energy by transferring an element between its natural fluid or gas states. Through this revolutionary process, designed by Energy Dome, it would deliver electricity to the grid when it is needed or take electricity and store its energy when the grid has excess electricity.  

Alliant Energy, WEC Energy Group and MGE co-own the Columbia Energy Center. Also partnering on this project are Shell Global Solutions U.S., Electric Power Research Institute (EPRI), UW-Madison and Madison College.  

The partners submitted an application to the Public Service Commission of Wisconsin in August 2024. Pending approval, construction is expected to begin in 2026, with completion expected by the end of 2027. 

The Columbia Energy Storage Project would be built south of Portage in the Town of Pacific, near the current Columbia Energy Center. This site allows the use of existing electrical infrastructure while the partners work to advance the next generation of sustainable energy.