Perryman
Harford County, Maryland · EIA plant ID 1556 · Operator: Constellation Power Source Gen
Nameplate492MWSummer 404 MW
Generators5in service
Net generation404GWh12 mo to Aug 2026
Capacity factor11%gas/coal/oil units, summer MW
Heat rate11,514Btu/kWhfossil units, electric fuel, HHV
First online1972Runs as peaking
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), gas/coal/oil units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 301.9 | 9.6% | 12,069 |
| 2002 | 181.4 | 5.8% | 12,813 |
| 2003 | 105.1 | 3.3% | 13,913 |
| 2004 | 138 | 4.4% | 12,305 |
| 2005 | 127.4 | 4.0% | 15,704 |
| 2006 | 72.2 | 2.3% | 14,058 |
| 2007 | 54 | 1.7% | 13,785 |
| 2008 | 74.7 | 2.4% | 13,949 |
| 2009 | 55.5 | 1.8% | 12,961 |
| 2010 | 69.5 | 2.2% | 13,651 |
| 2011 | 66.1 | 2.1% | 13,155 |
| 2012 | 102 | 3.3% | 12,752 |
| 2013 | 93.3 | 3.0% | 12,841 |
| 2014 | 116.9 | 3.8% | 13,509 |
| 2015 | 430.2 | 11.8% | 10,900 |
| 2016 | 552.8 | 15.1% | 10,455 |
| 2017 | 228.4 | 6.5% | 10,573 |
| 2018 | 271 | 7.7% | 10,838 |
| 2019 | 203.1 | 5.7% | 10,311 |
| 2020 | 193.5 | 5.5% | 11,150 |
| 2021 | 239.9 | 6.8% | 11,496 |
| 2022 | 329.8 | 9.3% | 10,857 |
| 2023 | 246.9 | 7.0% | 11,219 |
| 2024 | 152.4 | 4.3% | 11,634 |
| 2025 | 250.8 | 7.1% | 11,287 |
Fuel capability
Gas-fired turbines (CT/GT/CA/CS) that can also burn liquid fuel. EIA-860 Schedule 3 for capability, EIA-923 for actual burn.
StatusLikely still dual fuel
Liquid fuel burned · 36 mo1,775,215 MMBtu
Last month with liquid burnAug 2026
Switch while operatingYes
Net summer MW on gas248
Net summer MW on oil248
Time gas → oilup to 1 h (EIA 1H)
Time oil → gasup to 1 h (EIA 1H)
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| GT1 | Petroleum Liquids | GT | 53.1 | 52 | Jan 1972 | Operating | — | coming soon |
| GT3 | Petroleum Liquids | GT | 53.1 | 51 | Apr 1972 | Operating | — | coming soon |
| GT4 | Petroleum Liquids | GT | 53.1 | 52 | Apr 1972 | Operating | — | coming soon |
| GT5 | Natural Gas Fired Combustion Turbine | GT | 192 | 139 | Jun 1995 | Operating | — | coming soon |
| GT6 | Natural Gas Fired Combustion Turbine | GT | 141 | 109.8 | Jun 2015 | Operating | — | coming soon |
| GT2 | Petroleum Liquids | GT | 53.1 | 51 | Apr 1972 | Retired Feb 2016 | — | coming soon |
Owner / operator
Operator: Constellation Power Source Gen. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Constellation Power Source Gen | 100.0% | 492 MW |
Nearby plants
Within 80 km.
| Archdiocese of Baltimore L | 2 MW | 0.5 km |
| Archdiocese of Baltimore J | 2 MW | 0.5 km |
| Baltimore City B | 2 MW | 0.8 km |
| Havre de Grace II - E at Perryman | 1 MW | 0.8 km |
| Baltimore City F | 2 MW | 0.8 km |
| Sod Run WTP A | 2 MW | 0.8 km |