Conowingo — Plant Summary
- EIA Plant ID
- 1574
- Capacity
- 530.8 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Harford, MD
- Operating Since
- 1928
- Generators
- 11
- Operator
- Constellation Power, Inc
- Parent Company
- Constellation Energy
- Annual Generation
- 1,548,934 MWh
- Capacity Factor
- 33.3%
- Balancing Authority
- PJM Interconnection, LLC
- ISO/RTO
- PJM
- NERC Region
- RFC
Conowingo
OperatingHydro
Ranked #1 of 2 Hydro plants in MD#47 of 1454 nationally
530.8 MW Hydro operating in Harford, MD — PJM Interconnection, LLC
EIAGEMWD
530.8 MW
Nameplate Capacity
11
Generators
units
Conventional Hydroelectric
Technology
1928
Operating Since
Location
Coordinates
39.6572, -76.1752
County
Harford, MD
Nearby Plants
- Essential Power Rock Springs LLCNatural Gas795.6 MW · 7.0 km
- Wildcat Point Generation FacilityNatural Gas1113.6 MW · 7.0 km
- Peach BottomNuclear2876.4 MW · 13.9 km
Ownership & Operator
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Constellation Power, Inc | Constellation Energy | — |
| Owner(s) | Constellation Power, Inc | Constellation Energy | — |
| Status | Operating | operating | — |
Ownership Chain
About
The Conowingo Dam is a large hydroelectric dam in the lower Susquehanna River near the town of Conowingo, Maryland. The medium-height, masonry gravity dam is one of the largest non-federal hydroelectric dams in the U.S., and the largest dam in the state of Maryland. The dam sits about 9.9 miles (16 km) from the river mouth at Chesapeake Bay, 5 miles (8 km) south of the Pennsylvania border and 45 miles (72 km) northeast of Baltimore, on the border between Cecil and Harford counties. The dam is privately owned by the Susquehanna Electric Company, a subsidiary of Constellation Energy.
Read more on WikipediaConowingo is a 530.8 MW hydroelectric power plant located in Harford County, Maryland. It began operating in 1928 and utilizes conventional hydroelectric technology. The plant is owned by Constellation Energy and operated by Constellation Power, Inc. It consists of 11 generators and uses water (WAT) as its primary fuel source.
In the most recent year with available data, Conowingo generated 1,548,934 MWh of electricity, achieving a capacity factor of 33.3%. The plant is the largest of its kind in Maryland and ranks 47th out of 194 hydroelectric facilities nationally. The plant's balancing authority is PJM Interconnection, LLC, and it resides within the RFC NERC region.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
RFC
Balancing Authority
PJM Interconnection, LLC
Grid Voltage
220 kV
Regulatory Status
NR
Entity Type
Independent Power Producer
Sector
IPP Non-CHP
Generation
83.5K MWh
Latest Month
1.5M MWh
Annual Generation
33.3%
Capacity Factor
Jan 2023 – Dec 2025
Financial Data
No financial data available for this plant.
Pricing & Market Data
HIGH confidencePoint of Interconnection
Nearest Substation
Conowingo
Substation Distance
< 10 km
Coord Source
OSM spatial
Market Position
ISO/RTO Market
PJM
LMP Node
CONOWING13 KV G10
Pricing Hub
WESTERN HUB
Location Type
Generation Node
Node Source
EIA-860 direct report
News & Articles (10)Beta
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Last updated 2026-03-14
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