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Union Power Station

Gas power plant in Arkansas, United States of America. Approximate location 33.2961, -92.5894.

GasArkansasUnited States of AmericaCCGT · HRSG

Union Power Station is a 2,428 MW gas power station in Arkansas, United States of America. It is operated by Entergy Arkansas LLC. Based on reported annual generation of 11,268 GWh, it can supply roughly 3.2 million homes. It ranks #124 of 10,938 United States of America power plants by installed capacity. Commissioned in 2003, it is around 23 years old — relatively modern. 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).

2,428Source-backed capacity
4HRSG unit(s)
11,268GWh reported / yr
3,219,285homes powered
2003commissioned (~23 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id USA0055380.

Data status

Known data

FacilityUnion Power Station WRI
CountryUnited States of America · Arkansas WRI
Coordinates33.2961, -92.5894 WRI
FuelGas WRI
MW installed capacity2,428 MW WRI source record; scope not independently normalised
OwnerEntergy Arkansas LLC WRI
Commissioned2003 WRI
TechnologyCCGT · HRSG WRI
GWh reported / yr11,268 GWh/yr WRI

Calculated from dataset

CO₂ emissions4,507,000 t CO₂/yr calculated
Capacity rank in country#124 of 10938 calculated
Fuel-specific rank in country#22 of 2165 calculated
Capacity vs country/fuel peers20.03× · 121 MW median · 2165 peers calculated
Homes-powered equivalent3,219,285 calculated from reported generation
Climate17.2°C · HDD 1,337 derived from coordinates
Environmental severityC3 · 37/100 derived from coordinates

Not available

GWh reported / yrNot available not in dataset

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 L100000401911); fuel: WRI source-record fuel

In context: how this plant compares

At 2,428 MW, Union Power Station is well above the median gas plant in United States of America (121 MW). Technically it is described as CCGT; combined-cycle with a heat-recovery steam generator (HRSG). 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.

Reported generation trend

2013: 6,267 GWh20132014: 6,249 GWh20142015: 8,414 GWh20152016: 9,459 GWh20162017: 9,869 GWh20172018: 10,305 GWh20182019: 11,268 GWh201911k GWh

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

Owner

Operated by Entergy Arkansas LLC. All plants by this company →

Local climate & thermal context

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 33.3°N — which shapes how much energy it can produce and how its output varies through the year.

17.2°Cannual mean temp
1,337heating degree-days (base 18°C)
1,080cooling degree-days (base 18°C)
65 melevation

Monthly mean temperature

J: 6 °CJF: 9 °CFM: 13 °CMA: 17 °CAM: 22 °CMJ: 26 °CJJ: 28 °CJA: 27 °CAS: 24 °CSO: 18 °CON: 12 °CND: 8 °CD28 °C

Heating degree-days here run 46% 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: 31/100 — this site sits in the bottom third of the power plants we cover by heating degree-days.

A gas turbine here also runs ~2% 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.

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)
37/100environmental-severity index
21.5°Cseasonal temperature swing
431 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 #22 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.

Nearby power plants

Location

Coordinates 33.2961, -92.5894 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Union Power Station?

Union Power Station is a 2,428 MW source-record gas power plant in Arkansas, United States of America, commissioned in 2003.

How much electricity does Union Power Station generate?

Union Power Station generates about 11,268 GWh of electricity per year.

How many homes can Union Power Station power?

Its output is enough to supply roughly 3,219,285 homes.

Who operates Union Power Station?

Union Power Station is operated by Entergy Arkansas LLC.

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