In Merrimack County, New Hampshire (NH). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.

How big is Merrimack?

496 MW of nameplate capacity across 4 units, as of the EIA-860M release for 2026-07.

EIA-860M names Granite Shore Power as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.

Is this the same as Merrimack LLC?

Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Granite Shore Power here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Merrimack LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.

Is Merrimack still running?

EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.

Merrimack

Merrimack is a 496 MW coal power plant in Merrimack County, New Hampshire, operated by Granite Shore Power. EIA-860M lists 4 generating units here, inside ISO New England. Its units entered service between 1960 and 1969.

As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m

Nameplate capacity: 496.4 MW; 472.1 MW net summer
Generating units: 4
In service: 1960–1969
EIA plant ID: 2364

Where it is

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County: Merrimack County, New Hampshire
Coordinates: 43.1411, -71.4692
Balancing authority: ISNE
Sector: IPP Non-CHP

Units, technology and status

Operator of record: Granite Shore Power
Primary energy source: Coal
Technologies: Conventional Steam Coal, Petroleum Liquids
Status: Operating (3) · Out of service and NOT expected to return to service in next calendar year (1)

This site runs on more than one energy source. EIA-860M capacity splits: Coal 459 MW, Petroleum 37 MW. It is filed here under Coal, the source with the most capacity.

Every plant Granite Shore Power reports to EIA →

Merrimack: FAQ

Where is Merrimack?: In Merrimack County, New Hampshire (NH). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
How big is Merrimack?: 496 MW of nameplate capacity across 4 units, as of the EIA-860M release for 2026-07.
Who owns Merrimack?: EIA-860M names Granite Shore Power as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
Is this the same as Merrimack LLC?: Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Granite Shore Power here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Merrimack LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Merrimack still running?: EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.