In Harford County, Maryland (MD). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.

492 MW of nameplate capacity across 5 units, as of the EIA-860M release for 2026-07.

EIA-860M names Constellation Power Source Generation, LLC as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.

Is this the same as Perryman LLC?

Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Constellation Power Source Generation, LLC here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Perryman LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.

Is Perryman still running?

EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.

Perryman

Perryman is a 492 MW natural gas power plant in Harford County, Maryland, operated by Constellation Power Source Generation, LLC. EIA-860M lists 5 generating units here, inside PJM. Its units entered service between 1972 and 2015.

As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m

Nameplate capacity: 492.3 MW; 403.8 MW net summer
Generating units: 5
In service: 1972–2015
EIA plant ID: 1556

Where it is

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County: Harford County, Maryland
Coordinates: 39.4428, -76.2218
Balancing authority: PJM
Sector: IPP Non-CHP

Units, technology and status

Operator of record: Constellation Power Source Generation, LLC
Primary energy source: Natural gas
Technologies: Natural Gas Fired Combustion Turbine, Petroleum Liquids
Status: Operating

This site runs on more than one energy source. EIA-860M capacity splits: Natural gas 333 MW, Petroleum 159 MW. It is filed here under Natural gas, the source with the most capacity.

Every plant Constellation Power Source Generation, LLC reports to EIA →

Perryman: FAQ

Where is Perryman?: In Harford County, Maryland (MD). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
How big is Perryman?: 492 MW of nameplate capacity across 5 units, as of the EIA-860M release for 2026-07.
Who owns Perryman?: EIA-860M names Constellation Power Source Generation, LLC as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
Is this the same as Perryman LLC?: Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Constellation Power Source Generation, LLC here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Perryman LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Perryman still running?: EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.