Gas power plant in Tennessee, United States of America. Approximate location 36.0278, -87.9861.
GasTennesseeUnited States of AmericaOCGT
Johnsonville is a 1,426 MW gas power station in Tennessee, United States of America. It is operated by Tennessee Valley Authority. Based on reported annual generation of 140 GWh, it can supply roughly 40k homes. It ranks #404 of 10,938 United States of America power plants by installed capacity. Commissioned in 1980, it is around 46 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 USA0003406.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
The public capacity above is the current source-record value. A 2026 tracker candidate lists 1,020 MW for Johnsonville Fossil Plant, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).
Capacity claim grade: B_SCOPE_PARENT_COMPLEX - recommended action: build_parent_complex_model - confidence: not_comparable_without_scope. This follows a claim-based data model: value + scope + source + confidence, rather than silently overwriting records.
The capacity and fuel fields on this page are source-record values from the upstream open dataset. They are useful for identification and ranking, but they have not been upgraded to a 2026 registry/GEM-location verified value.
capacity: WRI Global Power Plant Database source-record (legacy); fuel: WRI source-record fuel
At 1,426 MW, Johnsonville is well above the median gas plant in United States of America (121 MW). Technically it is described as OCGT. 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.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by Tennessee Valley Authority. All plants by this company →
This gas plant burns natural gas in a turbine — often in a combined-cycle setup — to generate electricity. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 36.0°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 19% below 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: 43/100 — this site sits in the mid 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.
For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a moderately corrosive environment (estimated ISO 9223 class C3 — Medium), with humidity / wetness the leading environmental stress.
Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.
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.
The #101 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.
Coordinates 36.0278, -87.9861 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
Johnsonville is a 1,426 MW source-record gas power plant in Tennessee, United States of America, commissioned in 1980.
Johnsonville generates about 140 GWh of electricity per year.
Its output is enough to supply roughly 40,057 homes.
Johnsonville is operated by Tennessee Valley Authority.
