Marshalltown
Marshalltown is a 189 MW natural gas power plant in Marshall County, Iowa, operated by Interstate Power and Light Co. EIA-860M lists 3 generating units here, inside MISO. Its units entered service in 1978.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 189 MW
- 156.5 MW net summer
- Generating units
- 3
- In service
- 1978
- EIA plant ID
- 1068
Where it is
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- County
- Marshall County, Iowa
- Coordinates
- 42.0474, -92.8594
- Balancing authority
- MISO
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Interstate Power and Light Co
- Primary energy source
- Natural gas
- Technologies
- Natural Gas Fired Combustion Turbine
- Status
- Operating
Marshalltown: FAQ
- Where is Marshalltown?
- In Marshall County, Iowa (IA). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Marshalltown?
- 189 MW of nameplate capacity across 3 units, as of the EIA-860M release for 2026-07.
- Who owns Marshalltown?
- EIA-860M names Interstate Power and Light Co as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Marshalltown LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Interstate Power and Light Co here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Marshalltown LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Marshalltown still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.