Watts Bar Hydro

Hydro power plant in Tennessee, United States of America. Approximate location 35.6197, -84.7855.

HydroTennesseeUnited States of America

Watts Bar Hydro is a 175 MW hydro power station in Tennessee, United States of America. It is operated by Tennessee Valley Authority. Based on reported annual generation of 1,133 GWh, it can supply roughly 324k homes. It ranks #2163 of 10,938 United States of America power plants by installed capacity. Commissioned in 1942, it is around 84 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.3% of United States of America's electricity; the national grid averages 384 gCO₂/kWh (43.0% low-carbon) (2025).

175Source-backed capacity
1,133GWh reported / yr
323,600homes powered
1942commissioned (~84 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0003420.

Data status

Known data

FacilityWatts Bar Hydro WRI
CountryUnited States of America · Tennessee WRI
Coordinates35.6197, -84.7855 WRI
FuelHydro WRI
MW installed capacity175 MW WRI source record; scope not independently normalised
OwnerTennessee Valley Authority WRI
Commissioned1942 WRI
GWh reported / yr1,133 GWh/yr WRI

Calculated from dataset

Capacity rank in country#2163 of 10938 calculated
Fuel-specific rank in country#105 of 1449 calculated
Capacity vs country/fuel peers21.82× · 8 MW median · 1449 peers calculated
Homes-powered equivalent323,600 calculated from reported generation
Climate14.4°C · HDD 1,989 derived from coordinates
Environmental severityC3 · 34/100 derived from coordinates

Not available

TechnologyNot available not in dataset
GWh reported / yrNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: GEM tracker 2026 (location L100000603958); fuel: WRI source-record fuel

In context: how this plant compares

At 175 MW, Watts Bar Hydro is well above the median hydro plant in United States of America (8 MW). Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Reported generation trend

2013: 1,225 GWh20132014: 842 GWh20142015: 974 GWh20152016: 706 GWh20162017: 890 GWh20172018: 1,086 GWh20182019: 1,133 GWh20191k GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Tennessee Valley Authority. All plants by this company →

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a humid subtropical climate (Köppen Cfa) — Northern Hemisphere, latitude 35.6°N — which shapes how much energy it can produce and how its output varies through the year.

14.4°Cannual mean temp
1,989heating degree-days (base 18°C)
677cooling degree-days (base 18°C)
255 melevation

Monthly mean temperature

J: 3 °CJF: 5 °CFM: 10 °CMA: 14 °CAM: 19 °CMJ: 23 °CJJ: 25 °CJA: 24 °CAS: 21 °CSO: 15 °CON: 9 °CND: 5 °CD25 °C

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.

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

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.

C3ISO 9223 corrosivity (indicative)
34/100environmental-severity index
22.2°Cseasonal temperature swing
501 kmdistance to coast

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.

How it compares & nearby plants

The #105 largest hydro power plant of 1449 in United States of America by capacity.

United States of America has 1449 hydro power plants in this dataset, together about 102,513 MW of capacity.

Nearby power plants

Location

Coordinates 35.6197, -84.7855 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Watts Bar Hydro?

Watts Bar Hydro is a 175 MW source-record hydro power plant in Tennessee, United States of America, commissioned in 1942.

How much electricity does Watts Bar Hydro generate?

Watts Bar Hydro generates about 1,133 GWh of electricity per year.

How many homes can Watts Bar Hydro power?

Its output is enough to supply roughly 323,600 homes.

Who operates Watts Bar Hydro?

Watts Bar Hydro is operated by Tennessee Valley Authority.

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