South Texas Project — Plant Summary
- EIA Plant ID
- 6251
- Capacity
- 2708.6 MW
- Primary Fuel
- Nuclear
- Technology
- Nuclear
- Status
- Operating
- Location
- Matagorda, TX
- Operating Since
- 1988
- Generators
- 2
- Operator
- STP Nuclear Operating Co
- Parent Company
- Constellation Energy
- Annual Generation
- 21,782,126 MWh
- Capacity Factor
- 91.9%
- Balancing Authority
- Electric Reliability Council of Texas, Inc.
- ISO/RTO
- ERCOT
- NERC Region
- TRE
South Texas Project
OperatingNuclear
Ranked #1 of 2 Nuclear plants in TX#6 of 57 nationally
2708.6 MW Nuclear operating in Matagorda, TX — Electric Reliability Council of Texas, Inc.
EIAGEMWD
2,708.6 MW
Nameplate Capacity
2
Generators
units
Nuclear
Technology
1988
Operating Since
Location
Coordinates
28.7950, -96.0481
County
Matagorda, TX
Nearby Plants
- Eldora Energy LLCBESS400 MW · 10.7 km
- Isaac SolarSolar51.6 MW · 10.8 km
- Peyton Creek Wind Farm LLCWind151.2 MW · 16.0 km
Ownership & Operator
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | STP Nuclear Operating Co | STP Nuclear Operating | — |
| Owner(s) | Austin Energy, City of San Antonio - (TX), Constellation Nuclear | Constellation Energy | — |
| Status | Operating | operating | — |
Ownership Chain
About
The South Texas Project Electric Generating Station, is a nuclear power station southwest of Bay City, Texas, United States. STP occupies a 12,200-acre (4,900 ha) site west of the Colorado River about 90 miles (140 km) southwest of Houston. It consists of two Westinghouse Pressurized Water Reactors and is cooled by a 7,000-acre (2,800 ha) reservoir, which eliminates the need for cooling towers.
Read more on WikipediaThe South Texas Project is a nuclear power plant located in Matagorda County, Texas. It has a total capacity of 2708.6 MW across two nuclear reactors. The plant began operating in 1988 and is owned by Constellation Energy. The operator is STP Nuclear Operating Co. South Texas Project ranks as the largest nuclear plant in Texas (1 of 2) and the fifth-largest in the United States (5 of 55).
In the most recent year with available data, the plant generated 21,782,126 MWh of electricity, achieving a capacity factor of 91.9%. The South Texas Project operates within the Electric Reliability Council of Texas (ERCOT) balancing authority, and is within the Texas Reliability Entity (TRE) NERC region.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
TRE
Balancing Authority
Electric Reliability Council of Texas, Inc.
Grid Voltage
256 kV
Regulatory Status
NR
Entity Type
Municipal
Sector
IPP Non-CHP
Generation
2.0M MWh
Latest Month
21.8M MWh
Annual Generation
91.9%
Capacity Factor
Jan 2023 – Dec 2025
Financial Data
No financial data available for this plant.
Pricing & Market Data
HIGH confidencePoint of Interconnection
Nearest Substation
South Texas Project Switchyard · 345 kV
Substation Distance
0.179 km
Operator
CenterPoint Energy
Coord Source
OSM spatial
Market Position
ISO/RTO Market
ERCOT
LMP Node
STP_STP_G1
Pricing Hub
HB_SOUTH
Secondary Zone
LZ_SOUTH
Location Type
Resource Node
Node Source
Curated node match
News & Articles (10)Beta
Last updated 2026-03-26
View all 10 articles