Cobble Mountain — Plant Summary
- EIA Plant ID
- 1630
- Capacity
- 33 MW
- Primary Fuel
- Hydro
- Technology
- Conventional Hydroelectric
- Status
- Operating
- Location
- Hampden, MA
- Operating Since
- 1930
- Generators
- 3
- Operator
- City of Holyoke Gas and Electric Dept.
- Parent Company
- —
- Annual Generation
- 7,825 MWh
- Capacity Factor
- 2.7%
- Balancing Authority
- ISO New England Inc.
- ISO/RTO
- ISONE
- NERC Region
- NPCC
Cobble Mountain
OperatingHydro
Ranked #5 of 31 Hydro plants in MA#384 of 1454 nationally
33 MW Hydro operating in Hampden, MA — ISO New England Inc.
EIAWD
33 MW
Nameplate Capacity
3
Generators
units
Conventional Hydroelectric
Technology
1930
Operating Since
Location
Coordinates
42.1171, -72.8646
County
Hampden, MA
Nearby Plants
- Russell (MA)Solar3 MW · 5.5 km
- International Paper Woronoco MillHydro2.8 MW · 6.0 km
- Indian River HydroHydro1.4 MW · 7.8 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | City of Holyoke Gas and Electric Dept. | — | — |
| Owner(s) | Springfield Water & Sewer Comm | — | — |
| Status | Operating | — | — |
Ownership Chain
No GEM tracker match for this plant — ownership chain unavailable.
About
Cobble Mountain is a 33 MW hydroelectric power plant located in Hampden County, Massachusetts. The plant began operating in 1930 and consists of three generators utilizing conventional hydroelectric technology. It is owned and operated by the City of Holyoke Gas and Electric Department. Cobble Mountain is connected to the ISO New England Inc. balancing authority and is within the Northeast Power Coordinating Council (NPCC) NERC region.
The plant's primary fuel source is water (WAT). In the most recent year with available data, Cobble Mountain generated 7,825 MWh of electricity, resulting in a capacity factor of 2.7%. Cobble Mountain is ranked as the 5th largest of 31 power plants in Massachusetts and 390th out of 1464 plants nationally.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
NPCC
Balancing Authority
ISO New England Inc.
Grid Voltage
69 kV
Regulatory Status
RE
Entity Type
Municipal
Sector
Electric Utility
Generation
570 MWh
Latest Month
7.8K MWh
Annual Generation
2.7%
Capacity Factor
Jan 2022 – Dec 2024
Financial Data
No financial data available for this plant.
Pricing & Market Data
HIGH confidenceMarket Position
ISO/RTO Market
ISO-NE
LMP Node
UN.COBBLEMT69 COBB
Pricing Hub
.H.INTERNAL_HUB
Node Source
Curated node match
News & Articles (3)Beta
Industry·technology
Why Blandford residents are leery of a proposed battery storage site
A proposed site of a 175-megawatt battery storage facility on North Blandford Road sits near two streams feeding Springfield's Cobble...
MassLive.com·6 months ago
Industry·technology
Water and Wastewater Infrastructure Renewal Program
Critical renewal projects financed by EPA's Water Infrastructure Finance and Innovation Act and the MA State Revolving Fund.
EPA (regulator)
ArcGIS StoryMaps·3 years ago
Industry·technology
Exploring A Water System From Mountain Reservoir To Bathroom Tap
The Cobble Mountain Reservoir is the source of drinking water for about 30 percent of Massachusetts.
WAMC·8 years ago
Last updated 2026-03-26
View all articles