ISO-NE Interconnection: Find Power, Navigate the Queue, Secure Your Site
ISO New England studies generators in clusters. Data centers and other large loads connect through their transmission owner today, while ISO-NE prepares a dedicated large-load process due at FERC on November 16, 2026. Explore ISO-NE's interconnection process with our interactive step-by-step guide, then use LandGate’s capacity and parcel data to find the sites that can actually connect.
ISO New England Interconnection at a glance
Quick facts | ISO-NE |
|---|---|
Who runs it | ISO New England runs the grid and interconnection studies for Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont. FERC approves its rules. |
Governing rules | ISO-NE’s tariff Schedule 22 for generators over 20 MW, effective September 1, 2026, with separate schedules for small generators and transmission projects |
Generator study process | A cluster study, with a 45-day request window and a 60-day engagement window, followed by the Cluster Study, a 90-day restudy if needed, and a facilities study of 90 or 180 days |
Current window | The first regular window opened October 5, 2026 and closes November 19, 2026. Later windows open 60 days after the prior cluster’s results meeting. |
Transitional cluster | ISO-NE issued the final report August 6, 2026. Interim results covered 23 projects totaling about 4,800 MW, with average upgrade costs of about $178 million per project for those seeking capacity service. |
Service types | Capacity Network Resource service, which adds a deliverability test and requires 100% site control, or Network Resource service for energy only |
Generator costs | Flat deposits at filing: a $50,000 initial deposit, a $250,000 study deposit and a $500,000 readiness deposit, for $800,000 total |
Withdrawal penalties | None before the Cluster Study. After that, at least the study deposit, rising to 5% of upgrade costs during a restudy, 10% during the facilities study and 20% after signing. |
Large-load threshold (proposed) | 50 MW or more of peak demand at one site, connected above 60 kV. Storage, hospitals, water treatment and some other facilities are excluded. |
How large loads connect | Today, through the transmission owner, with ISO-NE reviewing transmission changes. ISO-NE’s proposal adds a rolling application process modeled on SPP’s, with a $50,000 fee, a $150,000 study deposit and a $10,000-per-MW readiness deposit. |
Proposed large load services | Firm service for loads that bring their own new capacity, interim service for up to 7 years while that capacity comes online, and non-firm service that can be redispatched |
Large load rules status | Proposed. NEPOOL committees vote November 3 and November 12, and the FERC filing is due November 16, 2026. |
Peak demand, for scale | 25.3 GW on July 2, 2026, below its record of 25.9 GW on June 24, 2025 |
Last updated | November 3, 2026 |
ISO-NE Generator Interconnection Process
Generator interconnection,
step-by-step
ISO-NE studies generators in clusters, with a 45-day request window and flat deposits at filing. Projects choose between capacity service, which adds a deliverability test, and energy-only service. Withdrawal penalties start once the Cluster Study begins and rise at each stage after that.
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Prepare for the window. ISO-NE posts notice at least 30 days before each window opens. Decide between Capacity Network Resource service and energy-only Network Resource service.
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Apply during the 45-day window. Submit $800,000 in deposits, a point of interconnection and proof of site control, which must be 100% for capacity service.
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Customer engagement window. Over 60 days, ISO-NE holds a scoping meeting, and developers pick their final POI and sign a Cluster Study Agreement.
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Cluster Study. ISO-NE studies the cluster together and assigns upgrade costs. Where an area needs a major new line, it can run a separate planning study for it.
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Restudy, if needed. If withdrawals affect the cluster, ISO-NE restudies it over 90 days. Projects whose costs rose more than 25% can leave without a penalty.
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Facilities study. ISO-NE defines the facilities and upgrades over 90 or 180 days. Projects whose costs more than doubled can leave without a penalty.
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Sign the agreement and build. The developer signs the interconnection agreement, and the project should synchronize within seven years of its request.
ISO-NE Large Load Interconnection Process
Large Load interconnection,
step-by-step
Today, large loads in New England connect through their transmission owner, with ISO-NE reviewing the transmission changes. ISO-NE has proposed a dedicated process for loads of 50 MW or more, due at FERC on November 16, 2026. The steps below follow that proposal, so confirm current requirements with ISO-NE.
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Talk to your transmission owner. The transmission owner that would serve the site is the starting point, under today’s rules and the proposal.
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Check whether it’s a large load. The proposal covers loads of 50 MW or more at one site, connected above 60 kV. Loads already operating or far enough along in construction would be exempt.
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Apply. Applications would be accepted on a rolling basis, with a $50,000 fee, a $150,000 study deposit and a $10,000-per-MW readiness deposit.
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System Impact Study. ISO-NE would study the load’s grid impact over 90 days, with up to 120 more days if extra analysis is needed.
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Choose firm, interim or non-firm service. Firm service would require bringing your own new capacity. Interim service would bridge the gap for up to 7 years, and non-firm service could be redispatched when the grid is constrained.
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Sign the service agreement. ISO-NE, the customer and the transmission owner would negotiate the agreement over 60 days.
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Meet operating rules and energize. Large loads would need forecasting, telemetry, remote disconnect capability, a 20 MW-per-minute ramp limit and ride-through standards.
What's changed recently in ISO-NE interconnection
Last updated November 2026
ISO-NE switched to a new cluster process for generators in 2026, and its first regular window is open now. For large loads, ISO-NE is preparing a dedicated process in response to FERC, with a filing due in November. If your project is in New England, check which of these changes apply before the window closes.
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June 2026: Interim results from the Transitional Cluster Study covered 23 projects totaling about 4,800 MW, with average upgrade costs of about $178 million per project for those seeking capacity service.
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June 18, 2026: FERC found ISO-NE’s tariff lacks an application process, study procedures and transmission services for large loads.
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August 6, 2026: ISO-NE issued the final Transitional Cluster Study report.
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September 1, 2026: ISO-NE’s new cluster rules for generators took effect.
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September 2026: ISO-NE released its large-load proposal, with a 50 MW threshold, three service options and proposed fees.
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October 5, 2026: The first regular cluster request window opened.
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October 2026: ISO-NE updated its large-load proposal to add a separate process for generators co-located with large loads.
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Coming up: NEPOOL votes on the large-load proposal on November 3 and 12, the FERC filing on November 16, and the close of the cluster window on November 19, 2026.
How LandGate Helps with ISO-NE Interconnection
Find powered sites in ISO-NE and analyze their suitability for data centers and other large loads using LandGate's nationwide data
Get your projects on the grid faster with reliable transmission data.
Make every request count
ISO-NE’s deposits are flat regardless of project size, so the only way to lower your risk is to apply at a better site. Search parcels by criteria such as distance to a substation and available offtake capacity, and see available transfer capacity at transmission-level injection points to find the strongest points of interconnection worth applying for.
Steer clear of costly upgrades
With interim upgrade costs averaging about $178 million per project seeking capacity service, knowing the grid before you apply matters. LandGate’s automated offtake capacity studies show substation details, capacity results, limiting elements, and queue information so you can estimate upgrade risks before MISO’s numbers arrive.
Find new capacity to pair with large loads
ISO-NE’s proposed firm service requires large loads to bring their own new capacity, and its October update adds a process for co-located generators. LandGate shows available transfer capacity at transmission-level injection points for generators and offtake capacity for loads at those same points, so you can evaluate both sides of a paired project.
Lock up the best sites
ISO-NE requires 100% site control for capacity service at filing. LandGate pairs its comprehensive grid data with proprietary landowner leads (listings), off-market properties, nationwide ownership data and contact information, and a map-based CRM to help you find, secure, and track the right parcels with your desired infrastructure profile.
