JOHNSONVILLE
Partly retiredCoal power plant
- Capacity
- 2,911 MW
- Primary fuel
- Coal
- County
- Humphreys County
- Operator
- TENNESSEE VALLEY AUTHORITY
- EIA plant ID
- 3406
- Generators
- 20
- Net generation (2024)
- 781 GWh
- Capacity factor (2024, EIA nameplate)
- 6.2%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 36.0279, -87.9863
JOHNSONVILLE, a partly retired 2,911 MW Coal power plant in Humphreys County, Tennessee. Most of its capacity was retired, most recently in 2017, according to EIA-860.
How JOHNSONVILLE compares
EIA-860 lists 1,426 MW still operable at the site (natural gas fired combustion turbine), against the 2,911 MW recorded for it. Its operator, TENNESSEE VALLEY AUTHORITY, runs 32 operating plants in Tennessee totaling 19,142 MW.
Under the same EIA plant code, EIA-860 lists 20 generators at the site with 1,426 MW of nameplate capacity (this page's HIFLD capacity figure is 2,911 MW). Net generation was 781 GWh in 2024 (a 6.2% capacity factor), down 8% from 2022. Its generators came online between 1975 and 2000.
Grid neighborhood
The nearest named substation is JOHNSONVILLE (500 kV), about 0.4 miles away; the closest transmission line found within 10 miles is a 161 kV line owned by TENNESSEE VALLEY AUTHORITY, under 0.1 miles away. One other operating power plant sits within 25 miles: WEST CAMDEN (5 MW).
Computed by Bywatts from HIFLD power plant, substation and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology
Weather peril exposure
JOHNSONVILLE is a partly retired 2,911 MW coal power plant in Humphreys County, TN, operated by TENNESSEE VALLEY AUTHORITY. Humphreys County carries elevated modeled catastrophe exposure in the FEMA National Risk Index, scoring 2.9 of 5 at the 48th national percentile. Earthquake is the leading peril, rated Relatively Low by FEMA at the 92nd 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.
Humphreys County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Earthquake | Relatively Low | 92nd | 4.7 of 5 | <0.01 |
| Tornado | Relatively Moderate | 87th | 4.5 of 5 | 0.44 |
| Strong wind | Relatively Moderate | 82nd | 4.3 of 5 | 4.3 |
| Riverine flooding | Relatively Low | 81st | 4.3 of 5 | 0.68 |
| Ice storm | Relatively Moderate | 79th | 4.2 of 5 | 0.71 |
| Hail | Very Low | 52nd | 3.1 of 5 | 3.2 |
| Heat wave | Relatively Low | 49th | 3.0 of 5 | 5.8 |
| Hurricane | Very Low | 48th | 2.9 of 5 | 0.02 |
| Lightning | Relatively Low | 45th | 2.8 of 5 | 58.0 |
| Winter weather | Very Low | 37th | 2.5 of 5 | 5.5 |
| Wildfire | Very Low | 18th | 1.7 of 5 | <0.01 |
Perils not assessed in Humphreys 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 Humphreys 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.