Northfield Mountain is a pumped-storage hydroelectric plant and reservoir located on and under the similarly named

Northfield Mountain Northfield Mountain, , is a mountain ridge located in Erving, Massachusetts, Erving and Northfield, Massachusetts. long by long, the mountain is composed of several distinct peaks and ledges, most notably Rattlesnake Mountain (also known as Farl ...

in Erving and

Northfield, Massachusetts Northfield is a New England town, town in Franklin County, Massachusetts, Franklin County, Massachusetts, United States. Northfield was first settled in 1673. The population was 2,866 at the 2020 census. It is part of the Springfield, Massachusetts ...

. It is currently owned by FirstLight Power Resources (formerly NE Energy), which purchased the facility from

Northeast Utilities Eversource Energy is a publicly traded, Fortune 500 energy company headquartered in Hartford, Connecticut, and Boston, Massachusetts, with several regulated subsidiaries offering retail electricity, natural gas service and water service to appro ...

in 2006.

History

Engineering studies for the plant began in October 1964, with early site preparation starting three years later. In 1972 its 1,168 megawatt

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

plant became operational as the largest such facility in the world. The facility was built to balance the supply from the nearby

Vermont Yankee Nuclear Power Plant Vermont Yankee was an electricity generating nuclear power plant, located in the town of Vernon, Vermont, in the northeastern United States. It generated 620 megawatts (MWe) of electricity at full power. The plant was a boiling water reacto ...

Design

The plant was built entirely underground, and located about up the

Connecticut River The Connecticut River is the longest river in the New England region of the United States, flowing roughly southward for through four states. It rises 300 yards (270 m) south of the U.S. border with Quebec, Canada, and discharges at Long Island ...

from

Turners Falls Turners Falls is an unincorporated village and census-designated place in the town of Montague in Franklin County, Massachusetts, United States. The population was 4,512 at the 2020 census. It is part of the Springfield, Massachusetts Metropol ...

Dam. A stretch of the

, extending some north from this dam to the Vernon Dam,

Vermont Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...

, serves as the station's lower reservoir. During periods of lower electrical power demand, the plant pumps water from this lower reservoir through the

Northfield Mountain Tailrace Tunnel The Northfield Mountain Tailrace Tunnel is a tunnel linking the Northfield Mountain pumped-storage hydroelectric facility to the Connecticut River in Millers Falls, Massachusetts. References Northeast Generation Company SEC Filing, 12/6/01 { ...

to a man-made upper reservoir. At times of high demand, water is released to flow downhill from this upper reservoir through a

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating e ...

generator, where it then collects in the lower reservoir to be stored until again pumped to the upper reservoir. Northfield Mountain's upper reservoir covers at above the river, with total storage of of water. Its underground powerhouse lies at below the surface and is accessible through a -long tunnel; it includes four large reversible turbines, each of which can pump of water per second and release of water per second to generate 1,143 MW of electricity. The turbines can

ramp up An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six clas ...

in 10 minutes, and deliver full power for 8 hours.

References

External links

* {{official website, url=https://www.firstlightpower.com/facilities/?location_id=346 Energy infrastructure completed in 1972 Pumped-storage hydroelectric power stations in the United States Hydroelectric power plants in Massachusetts