How big is Byron Generating Station?

Byron Generating Station reports 2,449.8 MW nuclear of operating nameplate capacity. These technology ratings do not establish a common export limit. Source: EIA Sep 2026.

What kind of plant is Byron Generating Station?

Byron Generating Station is a nuclear facility in Ogle County, IL, participating in the PJM market.

Where is Byron Generating Station located?

Byron Generating Station is in Ogle County, IL, inside the PJM balancing area.

Who operates Byron Generating Station?

Byron Generating Station is operated by Constellation Nuclear according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

How much electricity does Byron Generating Station generate?

Byron Generating Station reported 19,654.7 GWh over the twelve months to 2026-07. Figures are net generation as filed to EIA-923.

How does Byron Generating Station compare to other plants?

By capacity, Byron Generating Station ranks #9 of 54 operating plants of the same technology nationally. It ranks #1 of 6 in IL.

Byron Generating Station — 2,450 MW nuclear plant, IL

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Byron Generating Station — 2,450 MW nuclear plant, IL · Ask the Grid

Generation and physical site

EIA plant 6023 · Inventory for Sep 2026.

Reported operating nameplate by technology

Nuclear: 2,449.8 MW

Operating generators only. Battery power is in MW; stored energy is in MWh. These ratings do not establish a shared export limit.

Generator records (2)

EIA generator status and nameplate capacity for Byron Generating Station
Generator	Technology	Status	Power (MW)	Energy (MWh)
1	Nuclear	Operating	1,224.9	Unknown
2	Nuclear	Operating	1,224.9	Unknown

Physical map location · OpenStreetMap: 42.07413, -89.28265
Filed location · EIA: 42.07420, -89.28190

Sources and observation dates

Inventory source: EIA-860M workbook (preliminary)
EIA reporting month: Sep 2026
EIA retrieved: Oct 24, 2026
OSM extract: Oct 9, 2026
OSM last mapped edit: Nov 27, 2024
Map prepared: Oct 24, 2026
Field verification: Not reported

Reporting month describes the inventory. Retrieval and map preparation describe processing; an OSM edit does not establish an in-service date.

EIA source inventory

Units and generators

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

Generator	Capacity	Technology	Operation	Status
1	1,224.9 MW 1,164 MW summer	Nuclear ST	Sep 1985	Operating
2	1,224.9 MW 1,136 MW summer	Nuclear ST	Aug 1987	Operating

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

Cooling And Water Source

Closed-cycle cooling using two natural-draft cooling towers; Rock River makeup and receiving water

Circulating-water systems use two closed-cycle natural-draft cooling towers. Makeup water is withdrawn from the Rock River, and circulating-water blowdown is discharged back to Rock River under NPDES permit IL0048313.

Byron, Units 1 and 2 - Environmental Report, Part 1.

Cooling Water Intake Compliance

May 15, 1989

316(b) intake demonstration approved May 15, 1989

Illinois EPA approved station's Clean Water Act Section 316(b) demonstration on May 15, 1989. Later permit record states no additional intake monitoring or modification required for permit reissuance and no changes occurred in intake structure or cooling towers during prior permit cycle.

Source

Permitted Discharge Points And Waste Streams

Jan 24, 2011

Outfall 001 to Rock River; Outfalls 002, 003, 004 for stormwater-related discharges

Permit identifies Outfall 001 as cooling-system blowdown to Rock River, Outfall 002 as stormwater-runoff-basin overflow, Outfall 003 as East Station Area Runoff, Outfall 004 as West Station Area Runoff. Outfall 001 may combine cooling-tower blowdown with service-water blowdown, reverse-osmosis backwash, sewage-treatment effluent, wastewater-treatment effluent, radwaste-treatment effluent, stormwater-basin runoff, and intake-screen backwash.

Source

Wastewater Discharge Permit

Jan 24, 2011

NPDES Permit IL0048313

Illinois EPA issued NPDES Permit IL0048313 to Exelon Generation Company, LLC for Byron Nuclear Power Station. Permit issued and became effective January 24, 2011, and expired December 31, 2015. Later reissued permit identifier not established in available records.

Source

Mapped facility footprint

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.

Relationship graph

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AssetOwner / operatorContractor

Parties and identifiers

OrganizationRoleBasis

Constellation EnergyOwner / developerOwner / developer associated with Byron Generating Station.

Sargent & LundyEPC contractorArchitect-engineer associated with Byron Generating Station.

Reporting portfolio

EIA reporting entity

Constellation Nuclear

Entity 55951

Operating portfolio

12 plants

4 states

Reported capacity

22,817.3 MW

Nuclear

Largest reported plants in this portfolio
Largest reported plants	Capacity	State
Peach Bottom	2,876.4 MW	PA
Braidwood Generation Station	2,449.8 MW	IL
Byron Generating StationCurrent	2,449.8 MW	IL
LaSalle Generating Station	2,340 MW	IL
Limerick	2,277 MW	PA
Quad Cities Generating Station	2,018.6 MW	IL

Overview

Overview

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Infrastructure record

Profile

Structured profile

Generation and physical site

Reported operating nameplate by technology

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Units and generators

Performance

Peer context

Monthly generation

Grid and market context

Market registration

Nearby substations

Commercial, land, and environmental record

Land and environmental record

Related parties and identifiers

Relationship graph

Parties and identifiers

Reporting portfolio

Timeline and sources

Project timeline

Sources

Common questions about Byron Generating Station

How big is Byron Generating Station?

What kind of plant is Byron Generating Station?

Where is Byron Generating Station located?

Who operates Byron Generating Station?

How much electricity does Byron Generating Station generate?

How does Byron Generating Station compare to other plants?

Co-located assets

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