Watts Bar Hydro — United States of America

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

HydroTennesseeUnited States of America

Watts Bar Hydro is a 174.6 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 #2109 of 10,884 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).

174.6MW installed 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 capacity174.6 MW GEM · 2026 · L100000603958; operating plant capacity
Verification noteQuality label backfilled from existing source-backed capacity provenance on 2026-07-05; capacity value was not changed. source-verified
OwnerTennessee Valley Authority WRI
Commissioned1942 WRI
GWh reported / yr1,133 GWh·a⁻¹ WRI

Calculated from dataset

Capacity rank in country#2109 / 10884 calculated
Fuel-specific rank in country#105 / 1449 calculated
Capacity vs country/fuel peers21.82× · 8 MW · n=1449 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
CO₂ emissionsnot applicable not applicable

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

Data provenance

Source of the capacity and fuel values:

capacity: GEM · 2026 · L100000603958; fuel: WRI GPPD

In context: how this plant compares

At 174.6 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.

Key facts

Load factor
74%, from 1,133 GWh of reported generation; the median for 1342 hydro plants in United States of America that report generation is 42%
Generation trend
1,225 GWh in 2013 and 1,133 GWh in 2019 (−8%)
Highest and lowest year
2013: 1,225 GWh; 2016: 706 GWh
Share of United States of America hydro capacity
0.2% of 102,513 MW across 1,449 plants in this dataset
Age among peers
483 of 1,444 dated hydro 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

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).

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

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

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 174.6 MW 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.

Who operates Watts Bar Hydro?

Watts Bar Hydro is operated by Tennessee Valley Authority.

Built from open public data; no personal information. Operate this site? Request a correction or removal.