How big is San Miguel?

San Miguel has a reported capacity of 410 MW. Source: EIA Form 860.

What kind of plant is San Miguel?

San Miguel is a Conventional Steam Coal facility in Atascosa County, TX, participating in the ERCOT market.

Where is San Miguel located?

San Miguel is in Atascosa County, TX, inside the ERCOT balancing area.

Who operates San Miguel?

San Miguel is operated by San Miguel Electric Coop, Inc according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

When did San Miguel start operating?

San Miguel reports a commercial operation date of 1982. Current status: operating. Source: EIA Form 860.

How much electricity does San Miguel generate?

San Miguel reported 1,405.7 GWh over the twelve months to 2026-06. Figures are net generation as filed to EIA-923.

How does San Miguel compare to other plants?

By capacity, San Miguel ranks #134 of 206 operating plants of the same technology nationally. It ranks #10 of 11 in TX.

San Miguel — 410 MW coal plant, Atascosa County, TX

Overview

Net summer capacity: 391 MW
EIA May 2026
Nameplate capacity: 410 MW
EIA May 2026
Net winter capacity: 391 MW
EIA May 2026
Operating generators: 1
Lignite-fired steam unit
Planned solar: 400 MW
USDA New ERA plan
Planned storage: 200 MW
USDA New ERA plan
Resource stack: 1 resource
SANMIGL_G1

Infrastructure record

Operator: San Miguel Electric Coop, Inc

Profile

Grid role: Member-owned dispatchable lignite generation serving rural electric cooperatives in ERCOT.
Operating configuration: One conventional steam-coal generator fueled by locally mined lignite.
Capacity scope: EIA reports 410 MW nameplate and 391 MW net summer and winter capability; the cooperative also reports 391 net MW.
Planned transition: USDA-supported plans call for 400 MW of solar and 200 MW of battery storage; these are future replacement resources, not current coal-unit capacity.

Structured profile

Net capacity: 391 MW
EIA and cooperative
Nameplate capacity: 410 MW
EIA May 2026
Owner and operator: San Miguel Electric Cooperative
Cooperative
Planned transition: 400 MW solar + 200 MW battery
USDA New ERA plan

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Units and generators

Operating generator records and technology attributes reported through EIA-860.

Generator	Capacity	Technology	Operation	Status
1	410 MW 391 MW summer	Conventional Steam Coal Lignite · ST	Jan 1982	Operating

Performance

Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.

Peer context

Technology capacity: 410 MW
National rank: #134
TX rank: #10

Monthly generation

Download CSV

Latest 12 months

1.41 TWh

Reported net generation

Latest report

Jun 2026

EIA-923 monthly filing

2025 capacity factor

39.6%

Using current reported nameplate capacity

Grid and market context

Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.

Market registration

ERCOT public disclosures

Settlement point

SAN_SANMIGG1

high confidence spatial and capacity match

Market resources

1 resource

Commercial, land, and environmental record

Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.

Land and environmental record

Air Permit

Permit No. 101700

TCEQ AIR NEW SOURCE PERMITS; REGISTRATION; status ACTIVE

TCEQ AIR NEW SOURCE PERMITS: 101700

Air Permit

Permit No. 123647

TCEQ AIR NEW SOURCE PERMITS; REGISTRATION; status ACTIVE

TCEQ AIR NEW SOURCE PERMITS: 123647

Air Permit

Permit No. 4180A

TCEQ AIR NEW SOURCE PERMITS; PERMIT; status ACTIVE

TCEQ AIR NEW SOURCE PERMITS: 4180A

Air Permit

Permit No. 54118

TCEQ AIR NEW SOURCE PERMITS; REGISTRATION; status ACTIVE

TCEQ AIR NEW SOURCE PERMITS: 54118

Air Permit

Permit No. 85

TCEQ AIR OPERATING PERMITS; PERMIT; status ACTIVE

TCEQ AIR OPERATING PERMITS: 85

Related parties and identifiers

Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.

Parties and identifiers

OrganizationRoleBasis

SANMIGL_G1Market resourcesLinked ERCOT resources.

plant:plant-6183Grid selectionCanonical asset page /assets/facilities/san-miguel.

Reporting portfolio

EIA reporting entity

San Miguel Electric Coop, Inc

Entity 16624

Operating portfolio

1 plants

Timeline and sources

Project milestones and public references behind the asset profile.

Project timeline

Jan 1982
Jan 1982
Coal unit entered serviceEIA May 202...
EIA reports January 1982 for the operating generator record.
Jul 13, 2026
Jul 13, 2026
Latest disclosed generation interval
ERCOT SCED disclosure is delayed, so plant performance windows end at the latest disclosed interval.

Overview

Infrastructure record

Profile

Structured profile

Related assets

Coleto Creek

Major Oak Power

Units and generators

Performance

Peer context

Monthly generation

Grid and market context

Market registration

Commercial, land, and environmental record

Land and environmental record

Related parties and identifiers

Parties and identifiers

Reporting portfolio

Timeline and sources

Project timeline

J K Spruce

Sandy Creek Energy Station

Fayette Power Project

Welsh

ERCOT disclosed dispatch

Generation

Output by hourlocal time · 90 days through Jul 13, 2026

Latest disclosed outputhourly · 2 weeks ending Jul 13, 2026

Settlement price economics

Operating context

Nearby substations

Sources

Common questions about San Miguel

How big is San Miguel?

What kind of plant is San Miguel?

Where is San Miguel located?

Who operates San Miguel?

When did San Miguel start operating?

How much electricity does San Miguel generate?

How does San Miguel compare to other plants?