38th largest plant in Massachusetts · 4094th nationally
Cobble Mountain is a hydroelectric power plant in Massachusetts with a nameplate capacity of 33.0 MW. It generates roughly 10.5k MWh per year — enough to power about 1,002 average U.S. homes.
Its capacity factor of 4% reflects intermittent or peaking operation.
| Plant Name | Cobble Mountain |
|---|---|
| Operator | City Of Holyoke Gas And Electric Dept. |
| City | Granville |
| County | Hampden County |
| State | Massachusetts |
| ZIP | 01034 |
| Coordinates | 42.11711, -72.86466 |
This plant highlighted in navy-ringed pin; other generators within 25 miles shown as fuel-colored dots.
| ID | Technology | Fuel | Capacity | Status | Online |
|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | Water | 13.0 MW | Operating | 1930 |
| 3 | Conventional Hydroelectric | Water | 13.0 MW | Operating | 1930 |
| 2 | Conventional Hydroelectric | Water | 7.0 MW | Operating | 1930 |
| Owner | Location | Share |
|---|---|---|
| Springfield Water & Sewer Comm | Springfield, MA | 10000.0% |
Ownership reported to EIA Form 860. Percentages reflect reported generator-level ownership share, averaged when a plant has multiple generators.
| NERC Region | NPCC |
|---|---|
| Balancing Authority | Iso New England Inc. |
Hydroelectric plants spin turbines using falling or flowing water — typically from a dam-impounded reservoir. They are dispatchable, long-lived, and emission-free at the point of generation, though large reservoirs can disrupt rivers and ecosystems and methane can be released from flooded vegetation.