Perryman — 492 MW hybrid plant, Harford County, MD

Perryman — 492 MW hybrid plant, Harford County, MD · Ask the Grid

Generation and physical site

EIA plant 1556 · Inventory for Sep 2026.

Reported operating nameplate by technology

Petroleum: 159.3 MW
Natural gas: 333 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 (6)

EIA generator status and nameplate capacity for Perryman
Generator	Technology	Status	Power (MW)	Energy (MWh)
GT1	Petroleum Liquids	Operating	53.1	Unknown
GT3	Petroleum Liquids	Operating	53.1	Unknown
GT4	Petroleum Liquids	Operating	53.1	Unknown
GT5	Natural Gas Fired Combustion Turbine	Operating	192	Unknown
GT6	Natural Gas Fired Combustion Turbine	Operating	141	Unknown
GT2	Petroleum Liquids	Retired	53.1	Unknown

Physical map location · OpenStreetMap: 39.44013, -76.21583
Filed location · EIA: 39.44284, -76.22176

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: Dec 9, 2025
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
GT1	53.1 MW 52 MW summer	Petroleum Liquids GT	Jan 1972	Operating
GT3	53.1 MW 51 MW summer	Petroleum Liquids GT	Apr 1972	Operating
GT4	53.1 MW 52 MW summer	Petroleum Liquids GT	Apr 1972	Operating
GT5	192 MW 139 MW summer	Natural Gas Fired Combustion Turbine GT	Jun 1995	Operating
GT6	141 MW 109.8 MW summer	Natural Gas Fired Combustion Turbine GT	Jun 2015	Operating

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

Drag organizations to explore the network. Select a node to pin its details and available page link.

AssetOwner / operatorContractorEquipment

Parties and identifiers

OrganizationRoleBasis

Constellation Power Source Generation, LLCOperatorOwner / developer associated with Perryman.

Reporting portfolio

EIA reporting entity

Constellation Power Source Generation, LLC

Entity 4161

Operating portfolio

2 plants

1 states

Reported capacity

575.1 MW

Natural Gas Fired Combustion Turbine · Petroleum Liquids

Largest reported plants in this portfolio
Largest reported plants	Capacity	State
PerrymanCurrent	492.3 MW	MD
Philadelphia	82.8 MW	MD

Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.

View full reporting portfolio

Timeline and sources

Project milestones and public references behind the asset profile.

Project timeline

Jan 1972
Jan 1972
Generator enters operationEIA-860
EIA-860 lists generator GT1 with this operating date.
Apr 1972
Apr 1972
Generators enter operationEIA-860
EIA-860 lists generator GT3, generator GT4 with this operating date.
Jun 1995
Jun 1995
Generator enters operationEIA-860
EIA-860 lists generator GT5 with this operating date.
View 3 more milestonesHide 3 milestones
1. Mar 12, 2012
  Mar 12, 2012
  Corporate acquisition and ownership transitionSource
  Exelon and Constellation Energy completed their merger effective March 12, 2012. Exelon's SEC filing states that generation subsidiaries acquired from Constellation were contributed to Exelon's Generation business; this is the documented predecessor-owner transition for Perryman, not a separately priced plant sale.
2. Jul 26, 2013
Jun 28, 2015
Jun 28, 2015
Commercial operation — Perryman 6Exelon Gene...
Exelon Generation announced that the 120 MW Perryman 6 natural-gas generating unit began commercial operation on June 28, 2015.
Feb 2, 2022
Feb 2, 2022
Corporate separation into independent ConstellationExelon Comp...
Exelon completed the separation of Constellation Energy, described by Exelon as its former power-generation and competitive-energy business. The transaction was a corporate separation and not a disclosed Perryman-specific asset sale.
Mar 18, 2025
Mar 18, 2025
Withdrawal of Perryman 6 deactivation noticeMarch 18, 2...
Constellation withdrew the Perryman 6 deactivation notice and stated that the unit would be capable of returning to operation no later than the fourth quarter of 2025; the filing stated that Perryman 3 would continue operating.

Sources

PublisherReferenceType

U.S. Energy Information AdministrationEIA-860 generator inventoryFederal registry

U.S. Energy Information AdministrationEIA-923 generation filingsFederal filing

publicpower.orgFINANCIAL ARRANGEMENTS BEHIND NEW GENERATING CAPACITYother

Common questions about Perryman

Answered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.

How big is Perryman?

Perryman reports 159.3 MW petroleum + 333 MW natural gas of operating nameplate capacity. These technology ratings do not establish a common export limit. Source: EIA Sep 2026.

What kind of plant is Perryman?

Perryman is a Natural Gas Fired Combustion Turbine, Petroleum Liquids facility in Harford County, MD, participating in the PJM market.

Where is Perryman located?

Perryman is in Harford County, MD, inside the PJM balancing area.

Who operates Perryman?

Perryman is operated by Constellation Power Source Generation, LLC according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

How much electricity does Perryman generate?

Perryman reported 399.5 GWh over the twelve months to 2026-07. Figures are net generation as filed to EIA-923.

How does Perryman compare to other plants?

By capacity, Perryman ranks #169 of 829 operating plants of the same technology nationally. It ranks #3 of 8 in MD.

Co-located assets

Plants within 25 km, nearest first, regardless of technology. Proximity is straight-line distance between mapped plant coordinates; it does not by itself establish a shared point of interconnection.

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Overview

Overview

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Structured profile

Generation and physical site

Reported operating nameplate by technology

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Monthly generation

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Commercial, land, and environmental record

Land and environmental record