CT
Connecticut
2023 Avg LMP: $52/MWh
3,800 MW peak demand. Utilities: Eversource Energy + United Illuminating. Millstone Nuclear (2,098 MW) is the zone's dominant baseload resource — supplies ~50% of CT's electricity. High LMP zone driven by constrained imports from NY and MA. Net importer from NEMA/WCMA. Data center growth in Fairfield County adding load.
Key substations: Middletown 345kV · Norwalk Harbor 138kV · Montville 345kV
ME
Maine
2023 Avg LMP: $40/MWh
2,100 MW peak demand. Utility: Central Maine Power (Avangrid). Wind-rich zone — 1,000+ MW onshore wind in operation. Net exporter to WCMA during high-wind periods. Strong Gulf of Maine floating offshore wind potential (50+ GW resource at depths requiring floating foundations). Lowest LMP in ISO-NE reflecting surplus generation.
Key substations: Orrington North 345kV · Surowiec 345kV · Aldrich 115kV
NH
New Hampshire
2023 Avg LMP: $44/MWh
1,800 MW peak demand. Utility: Eversource NH. Mix of hydro (Connecticut River basin) + natural gas. Seabrook Nuclear (1,246 MW) dominates NH generation — among the largest single units in ISO-NE. Net exporter to MA at certain hours. Seacoast Reliability Project (2020, $230M) resolved prior constraint.
Key substations: Seabrook 345kV · Manchester 115kV · Garvins Falls 115kV
VT
Vermont
2023 Avg LMP: $42/MWh
1,100 MW peak demand. Utility: Green Mountain Power. Net importer since Vermont Yankee Nuclear (620 MW) retired 2014. Heavily dependent on Quebec hydro imports via Highgate HVDC interconnection and AC ties. Wind potential is limited by strict ridgeline development restrictions. Growing solar + demand response portfolio.
Key substations: Highgate HVDC 225kV · Burlington 115kV · Coolidge 115kV
RI
Rhode Island
2023 Avg LMP: $48/MWh
1,500 MW peak demand. Utility: National Grid RI. No major in-state baseload generation (one gas plant, Tiverton Energy Center). Offshore wind hub — Revolution Wind (704 MW) landing near South Kingstown/Providence. Submarine cable infrastructure rapidly developing. Well-positioned to become net exporter when OSW projects achieve COD.
Key substations: Davisville 115kV · Brayton Point 345kV (retired) · Kent County 115kV
WCMA
Western / Central Massachusetts
2023 Avg LMP: $46/MWh
4,200 MW peak demand. Utilities: Eversource West + National Grid. Springfield and Worcester metro. Major solar buildout ongoing across Pioneer Valley and central MA. Northfield Mountain pumped storage (1,080 MW) is a key flexibility resource for the entire ISO-NE system. Receives Maine wind exports. Relatively balanced net position.
Key substations: Northfield Mtn 345kV · West Springfield 345kV · Ludlow 345kV
SEMA
Southeastern Massachusetts
2023 Avg LMP: $49/MWh
3,100 MW peak demand. Utilities: Eversource SE + National Grid Plymouth. Plymouth County and Brockton area. Primary offshore wind cable landing zone for New England — Barnstable (Vineyard Wind) and South Kingstown cables terminate here. Grid reinforcement at Canal substation 345kV ongoing. Pilgrim Nuclear (672 MW) retired 2019 — created current import dependency.
Key substations: Canal 345kV · Barnstable 115kV · Braintree Electric Light 115kV
NEMA
NE Massachusetts / Boston
2023 Avg LMP: $55/MWh
4,800 MW peak demand. Utility: Eversource MA. Greater Boston metropolitan area — highest LMP zone in ISO-NE due to import constraints. Logan area gas peakers provide reliability during peak periods. Route 128 corridor data center growth driving incremental load. Key offshore wind load center — will benefit from SEMA OSW deliveries via upgraded 345kV backbone.
Key substations: South Boston 115kV · East Woburn 345kV · Wakefield Junction 345kV