Columbia Energy Storage Project

Energy Dome · Town of Pacific, Columbia County, WI · Wisconsin

First US CO2 battery: carbon dioxide is compressed into liquid to store energy and expanded through a turbine to release it, 10 hours at a time. Approved by Wisconsin regulators July 2025; construction 2026, done by end of 2027.

Long-duration storage · Multi-day, thermal and mechanical storage SEE CONNECTIONS →

ANNOUNCED
DEVELOPMENT
PERMITTED
FINANCED
CONSTRUCTION
OPERATING

Power

20 MW

Long-duration storage · First commercial

Storage

200 MWh

10-hour duration

Online

2027

approximate target

Capital committed

$30M

closed or awarded

Capital pending

—

conditional or under review

Capital stack

1 SOURCES

Grant $30M

Grant · US Department of Energy (Office of Clean Energy Demonstrations)About $30MAWARDED · 2023-09-26 · dailyenergyinsider.com$30M

Milestones

Jul 18, 2025Wisconsin PSC approves the project
2027 · APPROXIMATE TARGETConstruction complete (target)

Grid, permits and build

Permits: Wisconsin PSC approval (July 2025)
Who's building it

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Columbia Energy Storage Project

Capital stack

Milestones

Grid, permits and build

Columbia Energy Storage Project

Capital stack

Milestones

Grid, permits and build

Who buys and who finances

Dependencies

Related

Sources