Millstone — Plant Summary
- EIA Plant ID
- 566
- Capacity
- 2259.9 MW
- Primary Fuel
- Nuclear
- Technology
- Nuclear
- Status
- Operating
- Location
- New London, CT
- Operating Since
- 1975
- Generators
- 2
- Operator
- Dominion Energy Nuclear Conn Inc
- Parent Company
- —
- Annual Generation
- 16,708,717 MWh
- Capacity Factor
- 84.5%
- Balancing Authority
- ISO New England Inc.
- ISO/RTO
- ISONE
- NERC Region
- NPCC
Millstone
OperatingNuclear
Ranked #1 of 1 Nuclear plants in CT#21 of 57 nationally
2259.9 MW Nuclear operating in New London, CT — ISO New England Inc.
EIAGEMWD
2,259.9 MW
Nameplate Capacity
2
Generators
units
Nuclear
Technology
1975
Operating Since
Location
Coordinates
41.3107, -72.1677
County
New London, CT
Nearby Plants
- Yale New Haven - New LondonNatural Gas1.8 MW · 5.9 km
- Pfizer Groton PlantNatural Gas37.5 MW · 7.8 km
- Pfizer Groton Fuel CellNatural Gas5.6 MW · 8.5 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Dominion Energy Nuclear Conn Inc | Dominion Energy | Dominion Energy |
| Owner(s) | Dominion Energy Nuclear Conn Inc, Green Mountain Power Corp, Massachusetts Mun Wholes Electric Co | Dominion Resources Inc [100%] | — |
| Status | Operating | operating | — |
Ownership Chain
GEM identifies the owner as Dominion Resources Inc [100%]
This entity is not yet in the GEM ownership database — chain unavailable.
About
The Millstone Nuclear Power Station is the only nuclear power plant in Connecticut, United States, and the only multi-unit nuclear plant in New England. It is located at a former quarry in Waterford. With a total capacity of over 2 GW, the station produces enough electricity to power about 2 million homes. The operation of the Millstone Power Station supports more than 3,900 jobs, and generates the equivalent of over half the electricity consumed in Connecticut.
Read more on WikipediaMillstone is a nuclear power plant located in New London County, Connecticut. With a total capacity of 2259.9 MW across two generators, it is the largest power plant in Connecticut and ranks 20th nationally out of 55 nuclear plants. The plant began operating in 1975 and is owned and operated by Dominion Energy Nuclear Conn Inc. Millstone connects to the grid within the ISO New England Inc. balancing authority and the Northeast Power Coordinating Council (NPCC) NERC region.
In the latest year of available data, Millstone generated 16,708,717 MWh, achieving a capacity factor of 84.5%. Financial data indicates an installed cost of $3875.64 per kW, according to FERC filings.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
NPCC
Balancing Authority
ISO New England Inc.
Grid Voltage
345 kV
Regulatory Status
NR
Entity Type
Investor-Owned Utility
Sector
IPP Non-CHP
Generation
1.6M MWh
Latest Month
16.7M MWh
Annual Generation
84.5%
Capacity Factor
Jan 2023 – Dec 2025
Financial DataBeta
Source: FERC Form 1HIGH
$4,215/kW
Installed Cost
Green Mountain Power Corp
Reporting Utility
Cumulative Installed Cost
Per-Unit Cost Trends
Pricing & Market Data
HIGH confidencePoint of Interconnection
Nearest Substation
Millstone
Substation Distance
< 10 km
Coord Source
OSM spatial
Market Position
ISO/RTO Market
ISO-NE
LMP Node
UN.MILLSTONE3
Pricing Hub
.Z.CONNECTICUT
Node Source
EIA-860 direct report
News & Articles (10)Beta
Industry·corporate
CT must act now if it wants new nuclear power by 2035, state official says
HARTFORD — Connecticut's goal of having new nuclear power generation by 2035 will be hampered by the costs of construction,...
Connecticut (other)
CT Insider·4 days ago
Industry·corporate
Connecticut Pitches Return to Nuclear Power, But Fuel Supply Could Be a Hurdle
Connecticut is weighing a return to nuclear power, betting that a new generation of smaller reactors could help meet rising electricity...
Connecticut (other)
CT Examiner·2 months ago
Industry·corporate
CT and nuclear power. It’s a long-term relationship with questions about picking up the check.
Could CT have a nuclear energy future? Not if you're in a rush, millstone.
CT (other)millstone (operator)
Hartford Courant·4 months ago
Industry·corporate
Millstone nuclear power plant marks 50 years: Take a look inside
When the second reactor opened at Connecticut's Millstone Nuclear Power Station on Sept. 26, 1975, nuclear power was at the height of a...
Millstone Nuclear Power Station (operator)Connecticut (other)
CT Mirror·5 months ago
Last updated 2026-03-14
View all 10 articles