Nameplate capacity
492 MW
Rank in Maryland
#10
of 234 plants
In service since
1972
January 1972
Details
- Primary fuel
- Natural gas
- Technology
- Natural Gas Fired Combustion Turbine
- Operator
- Constellation Power Source Generation, LLC
- County
- Harford County
- Generating units
- 5
- Share of state capacity
- 3.70%
- Rank among natural gas plants in Maryland
- #6 of 15
- EIA plant code
- 1556
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| GT5 | Natural Gas Fired Combustion Turbine | 192 MW | 139 MW | 1995 | Operating |
| GT6 | Natural Gas Fired Combustion Turbine | 141 MW | 110 MW | 2015 | Operating |
| GT1 | Petroleum Liquids | 53 MW | 52 MW | 1972 | Operating |
| GT3 | Petroleum Liquids | 53 MW | 51 MW | 1972 | Operating |
| GT4 | Petroleum Liquids | 53 MW | 52 MW | 1972 | Operating |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Maryland
| Herbert A Wagner | Other | 774 MW |
| Conowingo | Hydro | 531 MW |
| Dickerson Power | Natural gas | 326 MW |
| Brandywine Power Facility | Natural gas | 289 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 492 MW solar plant and a 492 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Maryland power plants · What Maryland actually generates