MARION
OperatingCoal power plant
- Capacity
- 422 MW
- Primary fuel
- Coal
- County
- Williamson County
- Operator
- SOUTHERN ILLINOIS POWER COOP
- Status
- Operating
- Commissioned
- 1963
- EIA plant ID
- 976
- Generators
- 5
- Net generation (2024)
- 746 GWh
- Capacity factor (2024, EIA nameplate)
- 34%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 37.6198, -88.9531
MARION, a 422 MW Coal power plant in Williamson County, Illinois. Operated by SOUTHERN ILLINOIS POWER COOP, commissioned 1963.
How MARION compares
With 422 MW of capacity, MARION ranks 26th among the 158 operating power plants Bywatts maps in Illinois and 5th of the 12 operating Coal plants in the state. It accounts for about 5.5% of Illinois's operating Coal capacity and 1.0% of all operating capacity in the state. Nationally it is the 172nd-largest of the 324 operating Coal plants in the database. Commissioned in 1963, it is older than 87% of the 150 operating Illinois plants with a recorded commissioning year.
Under the same EIA plant code, EIA-860 lists 5 generators at the site with 249 MW of nameplate capacity (this page's HIFLD capacity figure is 422 MW). Net generation was 746 GWh in 2024 (a 34% capacity factor), down 5% from 2022. Its generators came online between 1963 and 2003.
Grid neighborhood
The closest transmission line found within 10 miles is a 161 kV line owned by AMEREN ILLINOIS COMPANY, about 0.1 miles away. One other operating power plant sits within 25 miles: SIUC (5 MW).
Computed by Bywatts from HIFLD power plant and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology
Weather peril exposure
MARION is a 422 MW coal power plant in Williamson County, IL, operated by SOUTHERN ILLINOIS POWER COOP, commissioned in 1963. Williamson County carries high modeled catastrophe exposure in the FEMA National Risk Index, scoring 3.8 of 5 at the 69th national percentile. Strong wind is the leading peril, rated Very High by FEMA at the 100th percentile.
The Bywatts loss layer is calibrated to solar PV hardware, so it is not applied to a coal plant. The ratings below are the FEMA National Risk Index county hazard ratings for this location.
Williamson County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Strong wind | Very High | 100th | 5.0 of 5 | 4.1 |
| Earthquake | Relatively Moderate | 96th | 4.8 of 5 | <0.01 |
| Winter weather | Relatively High | 91st | 4.6 of 5 | 7.6 |
| Ice storm | Relatively Moderate | 78th | 4.1 of 5 | 0.79 |
| Hail | Relatively Moderate | 66th | 3.6 of 5 | 3.3 |
| Riverine flooding | Relatively Low | 35th | 2.4 of 5 | 2.0 |
| Hurricane | Very Low | 33rd | 2.3 of 5 | 0.02 |
| Wildfire | Very Low | 31st | 2.2 of 5 | <0.01 |
| Tornado | Relatively Moderate | 30th | 2.2 of 5 | 0.37 |
| Heat wave | Relatively Moderate | 28th | 2.1 of 5 | 10.4 |
| Lightning | Relatively Moderate | 20th | 1.8 of 5 | 52.9 |
Perils not assessed in Williamson County
These perils carry no usable National Risk Index figure for this county, so they are excluded from the scoring rather than scored zero. A zero would claim the peril was assessed and found benign.
| Peril | Why it is not scored |
|---|---|
| Coastal flooding | FEMA rating is "Not Applicable" for this county |
Model hail, wind and flood exposure for Williamson County in the weather risk calculator
Ratings are the FEMA National Risk Index county hazard ratings; the peril score is a Bywatts transform of the FEMA national percentile. Full data sources and the solar vulnerability methodology are in the weather risk calculator.
Modeled estimate for screening and negotiation. Built from FEMA National Risk Index county hazard data and a solar vulnerability layer documented above. Not a quote, a binder, or actuarial advice, and not a substitute for a carrier's own model. Hazard data: FEMA National Risk Index December 2025, synced 2026-07-24. Resolution is county level, not site level.