Natural gasOperatingMISO

Union Power Station

Natural gas power plant in Union County, Arkansas. 2,428 MW of nameplate capacity across 12 generators, operated by Entergy Arkansas LLC.

Also known as EIA plant 55380

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El Dorado ARGeneral DynamicsMcClellan (AR)SR CamdenSAU TechGeorgia-Pacific Crossett LLCUnion25 km
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6 plants within 60 km, from EIA coordinates.

Key facts

Capacity
2,428 MWNameplate
Generators
12 operatingEIA-860M, August 2026
Operating since
January 2003First generator online
Operator
Entergy Arkansas LLCEIA operator ID 814
Grid
MISOBalancing authority MISO
Price nodes
16 MISO nodesResource nodes with prices
Location
Union County, AR33.2961, −92.5894
EIA plant ID
55380EIA plant page

Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.

How much power Union produces

Free · EIA-923

Net generation, 2025

10.1 TWh

10,096,173 MWh, final

Capacity factor, 2025

47.5%

2024: 51.2%

January to July 2026

7.32 TWh

Provisional

Range, 2016 to 2025

9.5–13.4

TWh a year. Low 2016, high 2023

Annual net generation, TWhCapacity factor below each year
Annual net generation from EIA-923
YearNet generation, MWhCapacity factorMonths reported
2000Not reportedNot reported0 of 12
2001Not reportedNot reported0 of 12
2002Not reportedNot reported0 of 12
2003Not reportedNot reported0 of 12
20042,603,284Not reported12 of 12
20052,900,927Not reported12 of 12
20064,464,749Not reported12 of 12
20073,581,910Not reported12 of 12
20082,546,418Not reported12 of 12
20094,215,142Not reported12 of 12
20106,376,86930.0%12 of 12
20117,190,17433.8%12 of 12
20129,911,29246.5%12 of 12
20136,267,016Not reported12 of 12
20146,248,56029.4%12 of 12
20157,810,73740.1%11 of 12
20169,459,44544.4%12 of 12
20179,869,06246.4%12 of 12
201810,305,17748.5%12 of 12
201911,267,49553.0%12 of 12
20209,620,71045.1%12 of 12
202111,206,83052.7%12 of 12
202212,788,41760.1%12 of 12
202313,416,47763.1%12 of 12
20249,989,43051.2%11 of 12
202510,096,17347.5%12 of 12
2026 (provisional, partial year)7,323,64659.3%7 of 7

* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.

Power prices and basis

Free account · MISO

Emissions

Free · EPA CAMPD

CO₂, 2025

4.36M

US short tons. 2024: 4.61M

SO₂, 2025

22

US short tons

NOx, 2025

498

US short tons

CO₂ per MWh, calculated

0.43 t

About 864 lb per MWh

8 of 8 EPA units reported CO₂ in 2025 (CTG-1, CTG-2, CTG-3, CTG-4, CTG-5, CTG-6, CTG-7, CTG-8), matched to EIA plant 55380 through the EPA–EIA crosswalk. The per-MWh rate is EPA CO₂ divided by EIA-923 net generation. The two reporting boundaries can differ.

Water use

Free · EIA-923 cooling, USGS

Withdrawal, 2024

2,742

million gallons

Consumption, 2024

2,742

million gallons

Source

Ouachita River

Surface, Fresh. Induced-draft tower

Watershed stress

Low · 0.209

USGS SUI, HUC12 Amason Creek

48 of 48 cooling months report withdrawal. SUI of the source river HUC12 within 3 km. Blank volumes are unreported, not zero.

Generators

Free · EIA-860M
GeneratorTechnologyNameplate MWOnline since
CTG1Natural Gas Fired Combined Cycle176.0January 2003
CTG2Natural Gas Fired Combined Cycle176.0January 2003
CTG3Natural Gas Fired Combined Cycle176.0April 2003
CTG4Natural Gas Fired Combined Cycle176.0April 2003
CTG5Natural Gas Fired Combined Cycle176.0May 2003
CTG6Natural Gas Fired Combined Cycle176.0May 2003
CTG7Natural Gas Fired Combined Cycle176.0June 2003
CTG8Natural Gas Fired Combined Cycle176.0June 2003
STG1Natural Gas Fired Combined Cycle255.0January 2003
STG2Natural Gas Fired Combined Cycle255.0April 2003
STG3Natural Gas Fired Combined Cycle255.0May 2003
STG4Natural Gas Fired Combined Cycle255.0June 2003

Ownership and offtake

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Pro

Ownership and offtake are part of Pro

Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists Entergy Arkansas LLC as the operator, which is not always the owner.

Modeled data

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Pro adds modeled values for this plant. Everything above stays free.

Modeled

Generation potential vs reported

Monthly potential at seasonal net capability, next to EIA-923 output. Shows how much of the plant's capability was used.

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Power plants near Union

More plants operated by Entergy Arkansas LLC

Questions about Union

How much power does Union Power Station produce?

Union Power Station reported 10,096,173 MWh (10.1 TWh) of net generation in 2025, a 47.5% capacity factor on 2,428 MW of nameplate capacity. From January to July 2026 it reported 7.32 TWh, which is provisional.

Where is Union Power Station?

Union Power Station is in Union County, Arkansas, at 33.2961, −92.5894. It is in the Midcontinent Independent Transmission System Operator, Inc.. balancing area (MISO).

Who operates Union Power Station?

EIA-860M for August 2026 lists Entergy Arkansas LLC as the operator (EIA operator ID 814). The operator is not always the owner.

When did Union Power Station start operating?

Its first generator began operating in January 2003, according to EIA-860M.

Does InfraMap have power prices for Union Power Station?

Yes. InfraMap has MISO day-ahead and real-time prices at 16 price nodes linked to Union Power Station, with the hub price and node-to-hub basis. Prices are free with an InfraMap account; pricing node names are part of InfraMap Pro.

Sources

  • EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
  • EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
  • EPA CAMPD annual emissions through the EPA–EIA crosswalk, 1995 to 2025
  • MISO day-ahead and real-time prices; node and hub assignments as of 2026-10-05
  • EIA-923 cooling water 2024 and the USGS surface water supply and use index, Water years 2010-2020 (Oct 2009 to Sep 2020), mean of monthly values

Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page