Merrimack
Merrimack County, New Hampshire · EIA plant ID 2364 · Operator: Granite Shore Power
Nameplate496MWSummer 472 MW
Generators4in service
Net generation2GWh12 mo to Aug 2026
Capacity factor0%gas/coal/oil units, summer MW
Heat rate16,467Btu/kWhfossil units, electric fuel, HHV
First online1960Runs 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 | 2,934.5 | — | — |
| 2002 | 2,877.4 | — | — |
| 2003 | 2,996.8 | 73.4% | 9,977 |
| 2004 | 3,127.8 | 76.4% | 9,933 |
| 2005 | 3,117.9 | 76.4% | 10,111 |
| 2006 | 3,161.7 | 77.4% | 11,095 |
| 2007 | 3,288.3 | 80.5% | 10,949 |
| 2008 | 2,853.5 | 69.7% | 11,122 |
| 2009 | 2,411 | 59.1% | 11,046 |
| 2010 | 2,668.4 | 62.9% | 10,571 |
| 2011 | 1,983.1 | 46.7% | 10,808 |
| 2012 | 1,186.3 | 28.6% | 10,903 |
| 2013 | 1,318.6 | 31.9% | 11,082 |
| 2014 | 1,152.9 | 27.9% | 10,802 |
| 2015 | 791.2 | 19.1% | 10,980 |
| 2016 | 360.4 | 8.7% | 11,761 |
| 2017 | 238.2 | 5.8% | 11,925 |
| 2018 | 549.6 | 13.3% | 11,306 |
| 2019 | 301.7 | 7.3% | 11,378 |
| 2020 | 128.7 | 3.1% | 11,789 |
| 2021 | 285.6 | 6.9% | 11,484 |
| 2022 | 308.8 | 7.5% | 12,668 |
| 2023 | 161.7 | 3.9% | 11,506 |
| 2024 | 225.7 | 5.4% | 11,617 |
| 2025 | 240.6 | 5.8% | 11,360 |
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 |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Steam Coal | ST | 113.6 | 108 | Dec 1960 | Operating · retirement planned | Dec 2027 | coming soon |
| 2 | Conventional Steam Coal | ST | 345.6 | 330.5 | May 1968 | Operating · retirement planned (Out of service) | May 2028 | coming soon |
| GT1 | Petroleum Liquids | GT | 18.6 | 16.8 | Aug 1968 | Operating | — | coming soon |
| GT2 | Petroleum Liquids | GT | 18.6 | 16.8 | Aug 1969 | Operating | — | coming soon |
Owner / operator
Operator: Granite Shore Power. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Granite Shore Power | 100.0% | 496 MW |
Nearby plants
Within 80 km.
| China Mill Hydro | 2 MW | 1.6 km |
| Pembroke Hydro | 3 MW | 1.7 km |
| Garvins Falls | 12 MW | 4.2 km |
| Hooksett | 2 MW | 4.4 km |
| Amoskeag | 16 MW | 15.4 km |
| Gregg Falls | 4 MW | 16 km |