9th largest plant in Maryland · 706th nationally
Conowingo is a hydroelectric power plant in Maryland with a nameplate capacity of 531 MW. It generates roughly 1.8M MWh per year — enough to power about 174,226 average U.S. homes.
Its capacity factor of 39% reflects intermittent or peaking operation.
| Plant Name | Conowingo |
|---|---|
| Operator | Constellation Power, Inc |
| City | Darlington |
| County | Harford County |
| State | Maryland |
| ZIP | 21034 |
| Coordinates | 39.65720, -76.17520 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| 10 | Conventional Hydroelectric | Water | 55.6 MW | Operating | 1964 |
| 11 | Conventional Hydroelectric | Water | 55.6 MW | Operating | 1964 |
| 8 | Conventional Hydroelectric | Water | 55.6 MW | Operating | 1964 |
| 9 | Conventional Hydroelectric | Water | 55.6 MW | Operating | 1964 |
| 3 | Conventional Hydroelectric | Water | 48.0 MW | Operating | 1928 |
| 7 | Conventional Hydroelectric | Water | 48.0 MW | Operating | 1928 |
| 4 | Conventional Hydroelectric | Water | 47.7 MW | Operating | 1928 |
| 6 | Conventional Hydroelectric | Water | 47.7 MW | Operating | 1928 |
| 1 | Conventional Hydroelectric | Water | 45.0 MW | Operating | 1928 |
| 2 | Conventional Hydroelectric | Water | 36.0 MW | Operating | 1928 |
| 5 | Conventional Hydroelectric | Water | 36.0 MW | Operating | 1928 |
| NERC Region | RFC |
|---|---|
| Balancing Authority | Pjm Interconnection, Llc |
Hydroelectric plants spin turbines using falling or flowing water — typically from a dam-impounded reservoir. They are dispatchable, long-lived, and emission-free at the point of generation, though large reservoirs can disrupt rivers and ecosystems and methane can be released from flooded vegetation.