Comanche iron-air battery

Form Energy · Comanche Generating Station, Pueblo, CO · Colorado DEVELOPER HEALTHWATCH

100-hour iron-air battery at the retiring Comanche coal plant. Form said it could come online as early as 2025; no newer status found.

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

ANNOUNCED
DEVELOPMENT
PERMITTED
FINANCED
CONSTRUCTION
OPERATING

Power

10 MW

Long-duration storage · First commercial

Storage

1 GWh

100-hour duration

Online

—

not announced

Capital committed

—

closed or awarded

Capital pending

$10M

conditional or under review

ONLINE DATE HISTORY · 2 CHANGES

Nov 9, 2026: Q3 2026 → none · source
Nov 6, 2026: none → Q3 2026 · source

How it works

Iron-air

Discharging lets iron pellets rust in air, which releases electricity; charging turns the rust back into iron. Cheap, plentiful materials make 100-hour storage affordable.

OPEN IN 3D →

Capital stack

1 SOURCES

Grant $10M

Grant · Breakthrough Energy CatalystCommitment to Xcel for the iron-air test projectsANNOUNCED · 2024-05-01 · denvergazette.com$10M

Milestones

Oct 1, 2025DOE says the Sherco and Comanche iron-air demonstration won't proceed; Xcel appeals

Grid, permits and build

Who's building it: Form Energy iron-air batteries (10 MW / 1,000 MWh)

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Comanche iron-air battery

Iron-air

Capital stack

Milestones

Grid, permits and build

Comanche iron-air battery

Iron-air

Capital stack

Milestones

Grid, permits and build

Who buys and who finances

Dependencies

Related

More from Form Energy

Sources