Herbert A Wagner
Other power plant · Anne Arundel County, Maryland
Nameplate capacity
774 MW
Rank in Maryland
#8
of 234 plants
In service since
1966
August 1966
Details
- Primary fuel
- Other
- Technology
- Petroleum Liquids
- Operator
- H.A. Wagner LLC
- County
- Anne Arundel County
- Generating units
- 2
- Share of state capacity
- 5.82%
- Rank among other plants in Maryland
- #1 of 19
- EIA plant code
- 1554
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 4 | Petroleum Liquids | 415 MW | 397 MW | 1972 | Operating |
| 3 | Petroleum Liquids | 359 MW | 305 MW | 1966 | 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
| Essential Power Rock Springs LLC | Natural gas | 796 MW |
| CPV St Charles Energy Center | Natural gas | 775 MW |
| Conowingo | Hydro | 531 MW |
| Perryman | Natural gas | 492 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 774 MW solar plant and a 774 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