Where is Marshalltown Generating Station?

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 Generating Station?

709 MW of nameplate capacity across 5 units, as of the EIA-860M release for 2026-07.

Who owns Marshalltown Generating Station?

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 Generating Station 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 Generating Station LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.

Is Marshalltown Generating Station still running?

EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.

Marshalltown Generating Station

Marshalltown Generating Station is a 709 MW natural gas power plant in Marshall County, Iowa, operated by Interstate Power and Light Co. EIA-860M lists 5 generating units here, inside MISO. Its units entered service between 2017 and 2020.

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: 708.8 MW; 668.1 MW net summer
Generating units: 5
In service: 2017–2020
EIA plant ID: 58236

Where it is

Loading map…

County: Marshall County, Iowa
Coordinates: 42.0433, -92.8728
Balancing authority: MISO
Sector: Electric Utility

Units, technology and status

Operator of record: Interstate Power and Light Co
Primary energy source: Natural gas
Technologies: Batteries, Natural Gas Fired Combined Cycle, Solar Photovoltaic
Status: Operating

This site runs on more than one energy source. EIA-860M capacity splits: Natural gas 706 MW, Solar 3 MW, Battery 0 MW. It is filed here under Natural gas, the source with the most capacity.

Every plant Interstate Power and Light Co reports to EIA →

Marshalltown Generating Station: FAQ

Where is Marshalltown Generating Station?: 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 Generating Station?: 709 MW of nameplate capacity across 5 units, as of the EIA-860M release for 2026-07.
Who owns Marshalltown Generating Station?: 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 Generating Station 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 Generating Station LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Marshalltown Generating Station still running?: EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.