Marshalltown Generating Station
Marshalltown Generating Station is a natural gas plant in Marshall County, Iowa, operated by Interstate Power and Light Co. It ranks fourth by nameplate capacity among Iowa’s 306 power plants. It is the biggest of Iowa’s 38 natural gas plants. Its units draw on three kinds of energy: natural gas, solar and battery storage.
Nameplate capacity, 2025
709 MW
668 MW net summer capacity
5 operable units
- Gas combined cycle706 MW100%
- Solar photovoltaic2.6 MW0.4%
- Battery0.3 MW0.0%
Unit by unit, 2017 to 2025
operating in 2025bar height follows unit size
Unit CTG1 Gas combined cycle, 223 MW, 2017
Unit CTG2 Gas combined cycle, 223 MW, 2017
Unit STG1 Gas combined cycle, 260 MW, 2017
Unit BESS1 Battery, 0.3 MW, 2020
Unit PV1 Solar photovoltaic, 2.6 MW, 2020
Among Iowa’s plants
Largest plants in the state by nameplate capacity, with the plants ranked next to this one.
- 1Walter Scott Jr Energy Center1,648 MW
- 2Louisa812 MW
- 3Ottumwa726 MW
- 4Marshalltown Generating Stationthis plant
- 5George Neal South696 MW
- 6Emery Station603 MW
Other rankings
- All US power plants
- 482nd of 14,286
- US natural gas plants
- 283rd of 1,961
- Plants in the MISO (Midcontinent) balancing area
- 72nd of 2,383
- Plants run by Interstate Power and Light Co
- 2nd of 29
- Biggest single unit, among Iowa’s plants
- 11th of 306
Operable units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| CTG1 | Gas combined cycle | 223 MW | 223 MW | 2017 | Operating |
| CTG2 | Gas combined cycle | 223 MW | 222 MW | 2017 | Operating |
| STG1 | Gas combined cycle | 260 MW | 220 MW | 2017 | Operating |
| PV1 | Solar photovoltaic | 2.6 MW | 2.6 MW | 2020 | Operating |
| BESS1 | Battery | 0.3 MW | 0.3 MW | 2020 | Operating |
Grid and site
- Balancing area
- MISO (Midcontinent)
- Reliability region
- Midwest Reliability Organization
- Highest grid connection voltage
- 161 kV
- Water source
- Municipality
- Nearest town on record
- Marshalltown
- Operator type
- Utility
- Coordinates
- 42.043°N, 92.873°W
Closest plants
| Plant | Runs on | Capacity | Distance |
|---|---|---|---|
| Marshalltown | Natural gas | 189 MW | 0.7 mi east |
| Alliant SBD 9107 JBS USA | Oil and petroleum | 11.4 MW | 1.5 mi northwest |
| Vienna Wind Farm | Wind | 150 MW | 9.4 mi northeast |
| Laurel Wind Farm | Wind | 123 MW | 11.5 mi south |
| State Center | Oil and petroleum | 7.1 MW | 15.0 mi west |
| Salt Creek Wind | Wind | 169 MW | 20.3 mi northeast |
| Ivester Wind Farm | Wind | 90.8 MW | 20.4 mi north |
| FPL Energy Story Wind LLC | Wind | 150 MW | 20.9 mi west |