Marshalltown — United States of America
Gas power plant in Iowa, United States of America. Approximate location 42.0474, -92.8594.
GasIowaUnited States of AmericaCCGT · HRSG
Marshalltown is a 189 MW gas power station in Iowa, United States of America. It is operated by Interstate Power and Light Co. Based on reported annual generation of 30 GWh, it can supply roughly 8.5k homes. It ranks #2043 of 10,884 United States of America power plants by installed capacity. Commissioned in 1978, it is around 48 years old — long-established. In context, gas supplies about 40.0% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0001068.
Data status
Known data
Calculated from dataset
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
Capacity provenance
The public capacity above is the current source-record value. A 2026 tracker candidate lists 706 MW for Marshalltown generating station, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).
Data provenance
Source of the capacity and fuel values:
capacity: GEM · 2026 · L100000402017; fuel: WRI GPPD
In context: how this plant compares
At 189 MW, Marshalltown is well above the median gas plant in United States of America (121.2 MW). Technically it is described as CCGT; combined-cycle with a heat-recovery steam generator (HRSG). Gas plants burn natural gas either in open-cycle turbines for fast peaking, or in combined-cycle units that recover exhaust heat in an HRSG to reach roughly 55–62% efficiency — the cleanest-burning fossil option.
Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.
Key facts
- Load factor
- 2%, from 30 GWh of reported generation; the median for 1622 gas plants in United States of America that report generation is 26%
- Generation trend
- 18 GWh in 2013 and 30 GWh in 2019 (+63%)
- Highest and lowest year
- 2019: 30 GWh; 2015: 2 GWh
- Share of United States of America gas capacity
- less than 0.1% of 789,950 MW across 2,165 plants in this dataset
- Age among peers
- 297 of 1,973 dated gas plants in United States of America are older
Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).
Reported generation trend
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Owner
Operated by Interstate Power and Light Co. All plants by this company →
Local climate & thermal context
This gas plant burns natural gas in a turbine — often in a combined-cycle setup — to generate electricity. It sits in a hot-summer humid continental climate (Köppen Dfa) — Northern Hemisphere, latitude 42.0°N — which shapes how much energy it can produce and how its output varies through the year.
Monthly mean temperature
Heating degree-days here run 51% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.
Climate heat-demand index: 80/100 — this site sits in the top third of the power plants we cover by heating degree-days.
A gas turbine here also runs ~0% below its ISO (15°C) rating at this annual mean (typical CCGT curve, estimate).
Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.
Site climate & environmental severity
This site sits in a mild atmospheric environment (estimated ISO 9223 class C2 — Low), with thermal cycling the leading environmental stress.
Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.
How it compares & nearby plants
The #933 largest gas power plant of 2165 in United States of America by capacity.
United States of America has 2165 gas power plants in this dataset, together about 789,950 MW of capacity.
Nearby power plants
- Sutherland Generating Station · Coal · 157 MW · Iowa
- Marshalltown Generating Station · Gas · 705.9 MW · Iowa
- Alliant SBD 9107 JBS USA · Oil · 11.4 MW · Iowa
- Vienna Wind Farm · Wind · 151 MW · Iowa
- Laurel Wind Farm · Wind · 123.4 MW · Iowa
- State Center · Oil · 6.3 MW · Iowa
Location
Coordinates 42.0474, -92.8594 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Frequently asked questions
What type of power plant is Marshalltown?
Marshalltown is a 189 MW gas power plant in Iowa, United States of America, commissioned in 1978.
How much electricity does Marshalltown generate?
Marshalltown generates about 30 GWh of electricity per year.
Who operates Marshalltown?
Marshalltown is operated by Interstate Power and Light Co.