Marshalltown Generating Station
Natural gas project in Marshall County, Iowa. 708.8 MW of nameplate capacity across 5 generators, operated by Interstate Power and Light Co.
Also known as EIA plant 58236
This project groups Marshalltown Generating Station (EIA 58236). EIA reports them as separate plants.
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 708.8 MWNatural gas 705.9 · Solar 2.6 · Battery storage 0.3
- Generators
- 5 operatingEIA-860M, August 2026
- Operating since
- April 2017First generator online
- Operator
- Interstate Power and Light CoEIA operator ID 9417
- Grid
- MISOBalancing authority MISO
- Price nodes
- 6 MISO nodesResource nodes with prices
- Location
- Marshall County, IA42.0433, −92.8728
- EIA plant ID
- 58236EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Marshalltown produces
Free · EIA-923Net generation, 2025
3.18 TWh
3,177,931 MWh, final
Capacity factor, 2025
51.2%
2024: Not reported
January to July 2026
1.57 TWh
Provisional
Range, 2018 to 2025
1.9–3.8
TWh a year. Low 2021, high 2019
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | Not reported | Not reported | 0 of 12 |
| 2001 | Not reported | Not reported | 0 of 12 |
| 2002 | Not reported | Not reported | 0 of 12 |
| 2003 | Not reported | Not reported | 0 of 12 |
| 2004 | Not reported | Not reported | 0 of 12 |
| 2005 | Not reported | Not reported | 0 of 12 |
| 2006 | Not reported | Not reported | 0 of 12 |
| 2007 | Not reported | Not reported | 0 of 12 |
| 2008 | Not reported | Not reported | 0 of 12 |
| 2009 | Not reported | Not reported | 0 of 12 |
| 2010 | Not reported | Not reported | 0 of 12 |
| 2011 | Not reported | Not reported | 0 of 12 |
| 2012 | Not reported | Not reported | 0 of 12 |
| 2013 | Not reported | Not reported | 0 of 12 |
| 2014 | Not reported | Not reported | 0 of 12 |
| 2015 | Not reported | Not reported | 0 of 12 |
| 2016 | Not reported | Not reported | 0 of 12 |
| 2017 | 1,307,628 | 29.1% | 9 of 12 |
| 2018 | 3,028,825 | 49.0% | 12 of 12 |
| 2019 | 3,761,078 | 60.8% | 12 of 12 |
| 2020 | 671,124 | Not reported | 3 of 12 |
| 2021 | 1,921,675 | 31.0% | 12 of 12 |
| 2022 | 2,724,002 | 43.9% | 12 of 12 |
| 2023 | 3,581,966 | 57.7% | 12 of 12 |
| 2024 | 3,498,948 | Not reported | 12 of 12 |
| 2025 | 3,177,931 | 51.2% | 12 of 12 |
| 2026 (provisional, partial year) | 1,568,227 | 43.5% | 7 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free account · MISOEmissions
Free · EPA CAMPDCO₂, 2025
1.39M
US short tons. 2024: 1.57M
SO₂, 2025
7
US short tons
NOx, 2025
85
US short tons
CO₂ per MWh, calculated
0.44 t
About 878 lb per MWh
2 of 2 EPA units reported CO₂ in 2025 (CT1, CT2), matched to EIA plant 58236 through the EPA–EIA crosswalk. The per-MWh rate is EPA CO₂ divided by EIA-923 net generation. The two reporting boundaries can differ.
Water use
Free · EIA-923 cooling, USGSWithdrawal, 2024
657
million gallons
Consumption, 2024
595
million gallons
Source
Marshalltown Water Works
Ground, Fresh. Induced-draft tower
Watershed stress
Low · 0.231
USGS SUI, HUC12 Timber Creek
12 of 12 cooling months report withdrawal. Groundwater user; SUI describes surface water and is context only. Blank volumes are unreported, not zero.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| BESS1 | Batteries | 0.3 | October 2020 |
| CTG1 | Natural Gas Fired Combined Cycle | 222.7 | April 2017 |
| CTG2 | Natural Gas Fired Combined Cycle | 222.7 | April 2017 |
| PV1 | Solar Photovoltaic | 2.6 | February 2020 |
| STG1 | Natural Gas Fired Combined Cycle | 260.5 | April 2017 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists Interstate Power and Light Co as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
Generation potential vs reported
Monthly potential at seasonal net capability, next to EIA-923 output. Shows how much of the plant's capability was used.
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Power plants near Marshalltown
More plants operated by Interstate Power and Light Co
Questions about Marshalltown
How much power does Marshalltown Generating Station produce?
Marshalltown Generating Station reported 3,177,931 MWh (3.18 TWh) of net generation in 2025, a 51.2% capacity factor on 708.8 MW of nameplate capacity. From January to July 2026 it reported 1.57 TWh, which is provisional.
Where is Marshalltown Generating Station?
Marshalltown Generating Station is in Marshall County, Iowa, at 42.0433, −92.8728. It is in the Midcontinent Independent Transmission System Operator, Inc.. balancing area (MISO).
Who operates Marshalltown Generating Station?
EIA-860M for August 2026 lists Interstate Power and Light Co as the operator (EIA operator ID 9417). The operator is not always the owner.
When did Marshalltown Generating Station start operating?
Its first generator began operating in April 2017, according to EIA-860M.
Does InfraMap have power prices for Marshalltown Generating Station?
Yes. InfraMap has MISO day-ahead and real-time prices at 6 price nodes linked to Marshalltown Generating Station, with the hub price and node-to-hub basis. Prices are free with an InfraMap account; pricing node names are part of InfraMap Pro.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- EPA CAMPD annual emissions through the EPA–EIA crosswalk, 1995 to 2025
- MISO day-ahead and real-time prices; node and hub assignments as of 2026-10-05
- EIA-923 cooling water 2024 and the USGS surface water supply and use index, Water years 2010-2020 (Oct 2009 to Sep 2020), mean of monthly values
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page