Merrimack
Merrimack is a coal plant in Merrimack County, New Hampshire, operated by Granite Shore Power. It ranks fourth by nameplate capacity among New Hampshire’s 61 power plants. The operator has reported planned retirement dates for 459 MW of it, between 2027 and 2028. Its biggest unit, rated at 346 MW, is the third-largest single generator in New Hampshire.
Nameplate capacity, 2025
496 MW
472 MW net summer capacity
4 operable units
- Coal steam459 MW93%
- Oil-fired37.2 MW7.5%
Unit by unit, 1960 to 2025
operating in 2025reported planned retirementbar height follows unit size
Unit 1 Coal steam, 114 MW, 1960
Unit 2 Coal steam, 346 MW, 1968
Unit GT1 Oil-fired, 18.6 MW, 1968
Unit GT2 Oil-fired, 18.6 MW, 1969
Among New Hampshire’s plants
Largest plants in the state by nameplate capacity, with the plants ranked next to this one.
Other rankings
- All US power plants
- 743rd of 14,286
- US coal plants
- 121st of 195
- Plants in the ISO New England balancing area
- 26th of 1,475
- Plants run by Granite Shore Power
- 1st of 5
Operable units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 1 | Coal steam | 114 MW | 108 MW | 1960 | Operating, retirement planned for 2027 |
| 2 | Coal steam | 346 MW | 330 MW | 1968 | Out of service, retirement planned for 2028 |
| GT1 | Oil-fired | 18.6 MW | 16.8 MW | 1968 | Operating |
| GT2 | Oil-fired | 18.6 MW | 16.8 MW | 1969 | Operating |
Grid and site
- Balancing area
- ISO New England
- Reliability region
- Northeast Power Coordinating Council
- Highest grid connection voltage
- 115 kV
- Water source
- Merrimack River
- Nearest town on record
- Bow
- Operator type
- Independent producer
- Coordinates
- 43.141°N, 71.469°W
Closest plants
| Plant | Runs on | Capacity | Distance |
|---|---|---|---|
| China Mill Hydro | Hydroelectric | 1.7 MW | 1.0 mi southeast |
| Pembroke Hydro | Hydroelectric | 2.7 MW | 1.1 mi southeast |
| Garvins Falls | Hydroelectric | 12.4 MW | 2.6 mi northwest |
| Hooksett | Hydroelectric | 1.6 MW | 2.7 mi south |
| Amoskeag | Hydroelectric | 16 MW | 9.6 mi south |
| Gregg Falls | Hydroelectric | 3.5 MW | 9.9 mi southwest |
| Wheelabrator Concord Facility | Biomass and waste | 14 MW | 11.4 mi northwest |
| Rolfe Canal Hydro | Hydroelectric | 4.3 MW | 11.5 mi northwest |