PGIQ Rating v2 (reliability-adjusted) · as of June 2026
3

🇺🇸 ISO New England

Viable, with conditions, holding steady● Under review Reliability flags found
Tier 3 Workable · Composite 48/100, #54 of 79 markets (fundamentals 53 minus a reliability dock) · Outlook Stable · High confidence · how we score

Small, expensive and winter-gas-constrained, with an offshore-wind-heavy pipeline slow to land. Workable, not a magnet.

See live grid data →

Grid conditions now

Structural baseline, June 2026Open the live map for ISO New England →
Demand
11,800 MW
Structural baseline, June 2026
Wholesale price
58/MWh
Structural baseline, June 2026
Carbon intensity
260 g/kWh
Structural baseline, June 2026
Low-carbon share
53%
Structural baseline, June 2026
One market,
four reads
BuildTier 3Siting ratingSelln/aOfftakePlanLightLoad pressureMonitorNot coveredSiting screen only
The same market, four decisions. Open any lens to see this market ranked against the rest.
Time to energize · file to power
~55 mo
File a large load today, powered ~2031. Typical range 47 to 63 months, measured.
End-to-end wait for a large new load, from a complete application being accepted to full firm energization of the nominated MW. Earlier milestones (initial, phased, temporary or conditional energization) are reported separately. A typical case, not a firm quote. · Source: LBNL Queued Up 2026 · Compare markets →

Sell power here

Not assessed. This read depends on the delivered cost of power, which is unavailable for this market: see the cost section for what is verified and what a serving utility must supply. No substitute value is used, because a missing cost would read as cheap power and flatter the result.

Regulatory momentum

The regulatory and permitting environment is increasingly the binding variable for a new large load.
Mixed→ stable

Why: FERC's 18 June 2026 Section 206 show-cause order requires ISO-NE to justify or reform how large loads connect, in a capacity-constrained, high-cost system where new demand competes for tight winter adequacy.

What would change the read: A Section 206 outcome that opens a workable large-load pathway without eroding ISO-NE's already tight capacity margin.

The five pillars behind the tier

A
A
C
M
C
The pillar signature: Access, Availability, Cost, Momentum, Carbon, taller is stronger. The same shape repeats across every market so peers compare at a glance.
Access30%52

Workable access with faster studies than most US ISOs (~3.6 yr), but a small, constrained system.

Availability25%50

Tight availability, especially winter gas constraints.

Cost25%None

Not assessed. The region-wide delivered-cost estimate was withdrawn under #320: regional transmission of about $21.57/MWh is verified and tariff-derived, but local transmission, distribution and demand charges are set by 32 serving utilities across six states, so no single ISO-NE figure exists. The verified partial is deliberately not scored, because a fraction of a delivered cost read as a whole one would flatter the pillar.

Momentum15%45

Lower momentum; offshore-wind-led pipeline is slow.

Carbon5%63

Carbon moderate (~240 g).

Default weights, which lean toward cost and access rather than carbon: Access 30 · Availability 25 · Cost 25 · Momentum 15 · Carbon 5. Momentum reflects the data-center build already underway, not just stated intentions.
Seller view: Read these the other way: momentum is your customer pipeline, cost is your revenue ceiling, and access is how hard it is to build and sell here, not only to connect.

Reliability overlay

Reliability adjustment: the five-pillar score of 53 is reduced to 48, a deduction of 5 points, reflecting the delivery-reliability and firm-supply risks flagged below. Reliability is reported as five separate layers, never as one combined label, because they answer different questions and a strong answer on one does not cover a gap in another: what has actually failed on the bulk system, what a forward assessment expects of firm supply, how the local network performs, what your contract actually promises, and what your site is designed to ride through. Any one of them can cap the tier.

Historical bulk-system performance: No reliability flags found

Historical utility-territory delivery performance: No reliability flags found

Average customer interruption (SAIDI) of 112.25 minutes per year in 2024, excluding major event days as filed.

measured · EIA Form 861, Schedules 3B and 3C (annual electric power industry report) (two major-event methods, IEEE; respondent-defined, customer-weighted blend of 32 of 35 territories, 99% of customers, regional context only)

A blend, not your supplier. This figure covers several distribution operators, so it describes an average customer rather than the operator that would serve your site. It is good for comparing markets and watching them move, it tops out at Comparable (M2), and it cannot carry a Project Case. mixed methods: IEEE 94%; respondent-defined 6% of customers. Major event days are excluded throughout; the methods differ only in how those days are identified, a smaller difference than the spread between the utilities themselves. Constituents below carry their own standard. It is a territory-wide history and is silent on: performance at a specific substation or feeder; transmission-level service, which is a different product from distribution service; the industrial or large-load customer class specifically; N-1 or other redundancy architecture at the supplying substation; contractual curtailment (being told to cut output or consumption) rights the utility may hold over the load; power quality and momentary interruptions, which this metric excludes by construction; on-site UPS, storage or generation; forward adequacy: it is a record of what happened, not a forecast.

The territories inside this market

The market figure above is an average across these territories. A project sits in one of them, not in the average. Each row is that operator’s own filed record; once a candidate site is matched to a territory, that row is the evidence that applies to it.

Territory operatorSAIDI min/yrCustomersMajor-event method
NSTAR Electric Company (MA)66.11,462,127IEEE 1366
Massachusetts Electric Co (MA)90.721,345,044IEEE 1366
Connecticut Light & Power Co (CT)76.91,326,461IEEE 1366
Central Maine Power Co (ME)215.4679,726IEEE 1366
Public Service Co of NH (NH)81.5551,456IEEE 1366
The Narragansett Electric Co (RI)60.79509,231IEEE 1366
United Illuminating Co (CT)49.2345,159IEEE 1366
Green Mountain Power Corp (VT)281.4275,233own method
Versant Power (ME)478.0165,401IEEE 1366
New Hampshire Elec Coop Inc (NH)514.8885,138own method
Unitil Energy Systems (NH)97.6679,654IEEE 1366
Liberty Utilities (Granite State Electri (NH)92.6945,565IEEE 1366
Vermont Electric Cooperative, Inc (VT)231.840,741IEEE 1366
City of Taunton (MA)192.9839,242IEEE 1366
Town of Reading - (MA) (MA)23.2432,638IEEE 1366
Fitchburg Gas & Elec Light Co (MA)64.630,873IEEE 1366
Town of Wallingford - (CT) (CT)37.1525,100own method
City of Norwich - (CT) (CT)287.9820,898IEEE 1366
City of Westfield - (MA) (MA)46.1218,194IEEE 1366
City of Holyoke - (MA) (MA)61.5817,557IEEE 1366
Town of Middleborough - (MA) (MA)19.1416,991own method
Town of Shrewsbury - (MA) (MA)16.616,986own method
Town of Braintree - (MA) (MA)2.5316,598IEEE 1366
City of Norwood - (MA) (MA)24.816,301IEEE 1366
Groton Dept of Utilities - (CT) (CT)22.4814,149IEEE 1366
Nantucket Electric Co (MA)50.413,995IEEE 1366
Town of North Attleborough - (MA) (MA)5.9513,894IEEE 1366
Town of Hudson - (MA) (MA)72.3913,515own method
Town of Danvers (MA)18.013,425own method
Eastern Maine Electric Coop (ME)737.1913,213IEEE 1366
Town of Mansfield - (MA) (MA)9.9610,504IEEE 1366
Bozrah Light & Power Company (CT)184.122,791IEEE 1366

Filed to EIA Form 861 for 2024, excluding major event days. Territory-wide averages: see the layer note above for what they do not establish.

Forward resource adequacy (assessed): Tight

NERC's 2024 assessment rates New England elevated-risk: persistent winter natural-gas constraints plus electrification-driven demand growth could raise shortfall risk by 2026, and extreme cold could challenge reliability further.

What this means: A large new load should expect genuine exposure to forced power cuts (curtailment), price spikes, and delays in getting connected, and should design in backup power or firm supply contracts.

assessed · NERC 2024 Long-Term Reliability Assessment

Contractual service terms: not assessed

We have not compiled what firm service actually promises here: whether it is firm, non-firm or interruptible, the conditions under which you can be curtailed, the redundancy required of you, and the transfer time behind any N-1 commitment. Treat this as an open diligence item, not as an indication that service is firm.

Ask the utility for the tariff or service agreement terms before relying on firm supply.

Designed site resilience: not applicable at market level

Utility feeds, UPS, storage, on-site generation, islanding, black start and the residual energy you still expect to lose are properties of a specific site design, not of a market. This layer only exists once there is a site, and we never assert it for you.

Confidence: Med-High. Each input is labelled as measured, modelled, or drawn from a specific event, and is framed as a risk to a prospective large new load, not as a verdict on any utility or grid operator. Forward adequacy is an assessment of what is expected, not a measurement of what has happened; it is a forecast and is labelled as one.
Seller view: Tight forward capacity (firm supply promised for future years) is scarcity that firm generation and storage get paid for; an adequacy flag is a demand signal for new supply, not only a risk to a load.

Supply relief outlook

Will the power crunch ease before your load energizes? This nets the demand racing for capacity against the new supply likely to arrive and the old supply leaving. A cross-side read, using the same data a seller sees the other way.
Tightening
Demand pressure
Moderate load growth competing for the same capacity.
New supply in motion
About 3.8 GW of the generation and storage queue is likely to reach operation after historical withdrawal.
Can new supply arrive
Regulatory momentum mixed, stable.
Future firm supply
Future firm supply: tight.

What this means: The supply picture looks likely to tighten; a new load should lock firm supply early and expect competition for capacity.

Reliability metrics

Delivery reliability (measured)

The average customer loses about 112.25 minutes of power per year (2024). This is the standard regulator outage measure (SAIDI); lower means a more reliable grid.

Averaged across 32 territories. No single customer experiences this figure. The per-territory table in the reliability overlay above gives each operator’s own filed record, which is what a site-specific read needs.

Source: EIA Form 861, Schedules 3B and 3C (annual electric power industry report) (two major-event methods, IEEE; respondent-defined, customer-weighted blend of 32 of 35 territories, 99% of customers, regional context only)

Hard, cited measures behind the reliability overlay above: the regulator outage series (SAIDI, measured, published with a lag) and the forward resource-adequacy assessment (a measured forecast). Framed as risk to a prospective large new load, not a verdict on any utility.

Interconnection queue (the line to connect to the grid)

These are generation and storage interconnection queues. They show how congested the interconnection system is. They do not measure how long a new large load waits, and their withdrawal rates are not load withdrawal rates. At the end of 2025, generation and storage projects totalling about 2,060 GW were actively waiting in United States queues, down 10% from a year earlier. Of the capacity that entered between 2000 and 2020, about 75% withdrew before connecting and only about 13% reached operation by end-2025. The typical project built in 2025 waited about 61 months from request to operation (Lawrence Berkeley National Laboratory, Queued Up 2026). Figures below are refreshed quarterly; each is labelled measured or modelled.

Active queue depth

15 GW

Typical wait

55 months

The full queue analysis for this market, which covers the share of projects that give up and leave the queue (the withdrawal rate), how much of the queue is data centers, and the sources, is available through /api/v1/queue/isone with a paid key. These are generation and storage queue figures: they show interconnection-system congestion, not a typical large-load connection wait.

Seller view: A deep queue is both your own time-to-revenue and a moat against competing supply; what matters is the effective supply likely to complete after withdrawal, not the headline queue.

Forward cost anchor

Siting a load is a decade-long cost bet, so the forward cost of firm capacity matters more than today's spot price. This is the public capacity-auction clearing price, the market's own forward read, not a paywalled forward curve.

Forward cost pressure

Moderate

Latest capacity clearing price

$3.58 per kW-month

2027/28 (FCA 18)

Trend: Rising, up about 40% from the prior auction; the next auction is delayed to 2028.

ISO New England's most recent capacity auction cleared at $3.58 per kW-month for 2027/28, up roughly 40%. The next auction is delayed to 2028, so this is the standing forward signal.

Source: ISO-NE Forward Capacity Auction 18 (Utility Dive). A derived indicator: we publish the public clearing price and our read, never paywalled exchange data.

Seller view: This capacity clearing price is a direct revenue signal for new supply: a rising trend supports the build thesis, a falling one is a warning.

Recurring cost

Verified regional transmission only
$21.57/MWh · regional transmission only

PowerGridIQ can verify approximately $21.57/MWh of current regional ISO-NE transmission charges for the standard archetype. A complete delivered-cost estimate is not available at the ISO-NE-wide level because local transmission, distribution and demand charges vary across 32 serving utilities and multiple state jurisdictions.

Regional Network Service (OATT Schedule 9)$21.34$177.62722/kW-yr, through 2026-12-31
Scheduling, System Control and Dispatch (OATT Schedule 1)$0.23$1.87420/kW-yr, from 2026-06-01

Complete delivered cost: insufficient evidence.

Next step. Identify the serving utility for the specific interconnection point and apply its current local transmission and distribution tariff. These are set at the utility and state level and exist nowhere regionally.

This figure is not a delivered-cost total; a cost-band midpoint; the low end of a band; a substitute for the withdrawn estimate; an input to the cost pillar.

Scheduled change · not in the figure above

Regional transmission rises to $22.29/MWh on 2027-01-01 (Pool RNS Rate rises to $183.59911/kW-yr).

Region-wide estimate withdrawn (#320). A single delivered-cost estimate cannot be defended at ISO-NE-wide scope. The regional transmission layer is uniform and verifiable, but local transmission, distribution and retail demand charges are set by 32 serving utilities across six states and five regulators. The superseded values are recorded in the correction record, not here.

Restored when: A serving utility and interconnection point are specified, so a local transmission and distribution tariff can be applied. This is a change of scope rather than a research task: no ISO-NE-wide figure will become available, because ISO-NE is not the entity that sets one. Withdrawn 2026-08-24. Correction record →

Seller view: This delivered price is the level a competitive supply offer must beat, and the revenue ceiling a merchant plant works against here.

Data provenance and freshness

What we hold for this market, field by field. Each tier below is assigned from the evidence actually held for that field, with provenance. A low tier means we looked and it is thin; it is not a verdict on the market.
cost: not_assessedconnection: M2reliability: M2carbon: M2regulatory: M2local capacity: not_assessed
Against a Standardized Project Case, these fields are not answered here at all: cost. Absence of a finding is not evidence of low risk, and it is a different statement from a low tier.
Read against other uses: Discovery and monitoring: insufficient · Market comparison: insufficient · Project Case with a carbon requirement: insufficient · Conditional site diligence: insufficient.
Depth is not a rating strength, a confidence score or a feasibility conclusion. An aggregate is only ever shown for a named use case, and equals the lowest tier across that use case's required fields. Definitions v1.0. See the full coverage matrix.
How solid the data behind this rating is, on two separate axes plus recency. Source reliability is how measured the numbers are, as opposed to triangulated or modelled. Coverage is how many of the decision-relevant data dimensions (reliability, connection, and cost) are compiled for this market. The two are kept apart because they answer different questions: a market can have strong sources on the little that is covered, or broad coverage that still leans on models. Neither grades the rating itself. The rating is a cited opinion, graded separately and falsifiably by the public track record and baseline measurement plan.

Source reliability

High

3 of 3 data layers measured

Coverage

Substantial

2 of 3 dimensions: reliability, connection, cost

Last reviewed

June 2026

per-layer vintages below

LayerMethodVintageFreshnessSource
PGIQ Rating opinionopinionJune 2026CurrentPGIQ methodology
Reliabilitymeasured2024FreshEIA Form 861, Schedules 3B and 3C (annual electric power industry report) (two major-event methods, IEEE; respondent-defined, customer-weighted blend of 32 of 35 territories, 99% of customers, regional context only)
Forward costmeasured2027/28 (FCA 18)FreshISO-NE Forward Capacity Auction 18 (Utility Dive)
Interconnection queuemeasuredend-2025 (LBNL 2026)FreshLBNL Queued Up 2026

Freshness reflects each layer's refresh cadence: reliability annual to three-yearly, capacity-auction and queue yearly, tariffs every year or two. The full cross-market freshness dashboard is at /data-quality.

What this market can and cannot answer yet

No market-level read closes a project case on its own, and saying only that would waste the evidence we do hold. Below is what is established, what is open, and what to do next.

What is established

  • Historical utility-territory delivery performance 112.25 minutes per year (2024)
  • Forward resource adequacy (assessed)
  • Typical interconnection wait about 55 months (generation and storage queue, not a load wait)

What is open

  • Historical bulk-system performance
  • Contractual service terms (would change the answer)
  • Designed site resilience
  • cost evidence (would change the answer)
  • local_capacity evidence

How service and connection are organized

Territories in this market, each with its own filed record: NSTAR Electric Company, Massachusetts Electric Co, Connecticut Light & Power Co, Central Maine Power Co, Public Service Co of NH, The Narragansett Electric Co, United Illuminating Co, Green Mountain Power Corp. Which one serves a given site depends on where that site is.
How the connection process is organised: the applicable service and connection entities depend on the candidate location and the power pathway. We have not compiled the structure for this market; that is a gap in our wayfinding, not a fact about the market.

Credible ranges today

  • Schedule: interconnection queues here run about 55 months for generation and storage; a large load follows a different process and we do not hold its measured distribution

What could disqualify this market

  • Winter reliability and gas dependence.
  • Slow offshore-wind pipeline.

Outlook drivers

↑ Upgrade triggers

  • Offshore wind energizes at scale.
  • Transmission upgrades ease winter constraints.

↓ Downgrade triggers

  • Winter gas-supply stress.
  • Offshore-wind delays persist.

Key risks

Peer comparison

Trades like
NYISO (small, constrained, pricey)
Ahead
on study speed
Behind
on scale
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Rating history

Jun 2026
AffirmedNamed in the FERC show-cause suite; preliminary stage, tier holds, monitoring.
Trigger: FERC Section 206 show-cause order (18 Jun 2026)
June 2026
New ratingNew rating: Tier 3 Workable assigned.
🔒 The full time series behind ISO New England, how its score, recurring cost, and interconnection queue have moved month by month, is part of the Analyst Desk. The rating actions above are always free.
Every rating action is dated and explained, and the log is only ever added to, never edited. Reviews happen on a regular schedule and whenever a significant event occurs. "Affirmed" means we reviewed a development and the tier held; "Under review" means a significant item is being assessed and the rating could change.

Score history

How ISO New England's reliability-adjusted score and tier have moved, month by month. Part of your Analyst Desk.

Immutable monthly snapshots of the reliability-adjusted score, tier, outlook and recurring cost, oldest first. Dated when taken and never back-filled, so the series only compounds forward. Part of the Analyst Desk →

Grid conditions now

Structural baseline, June 2026Open the live map for ISO New England →
Demand
11,800 MW
Structural baseline, June 2026
System demand across the market.
Wholesale price
58/MWh
Structural baseline, June 2026
Energy only, and always modelled: no live price feed exists in any market. This is not the delivered cost.
Carbon intensity
260 g/kWh
Structural baseline, June 2026
Derived from the fuel mix. Never directly measured.
Low-carbon share
53%
Structural baseline, June 2026
Wind, solar, hydro, geothermal, biofuel and nuclear. The emissions-free share of generation, which is the read for a carbon target.
Renewable share
31%
Structural baseline, June 2026
Wind, solar, hydro, geothermal and biofuel. Excludes nuclear, which is low-carbon but not renewable, so this is the read for an RE100-style renewable procurement mandate.
Installed capacity
28,000 MW
Structural baseline, June 2026
Firm capacity
not held
Structural baseline, June 2026
De-rated, system-level.
System firm margin
not held
Structural baseline, June 2026
Market-wide estimate of de-rated firm capacity less peak demand. This is a directional screen, not local connectable capacity at any point of delivery.
Imports
1,000 MW
Structural baseline, June 2026
Modelled. No live interchange feed exists.
Exports
200 MW
Structural baseline, June 2026
Modelled. No live interchange feed exists.

Every field above carries its own source and freshness. Price, imports and exports are modelled in every market because no feed supplies them. Carbon intensity is derived from the fuel mix.

What next for ISO New England?

Add to shortlistTrack it alongside your other candidates.Compare with peersRank markets against each other on your own weights.Open the Analyst DeskEvery market side by side, with history and alerts.Retrieve it through the APIThe same read as JSON, with provenance on every field.

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How does ISO New England compare to every other market?

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