NYISO Interconnection Queue for Data Centers, Explained

Why "the NYISO queue" means two different things

When people say a project is "in the NYISO queue," they usually mean the generator interconnection queue: solar, wind, storage, and gas plants asking to inject power. NYISO runs that as a two-phase cluster study under Attachment HH of its tariff. In Phase 1 the connecting and affected transmission owners look at local impacts and cost the attachment facilities; in Phase 2 NYISO studies the system-wide upgrades the whole cluster needs. That queue is crowded. NYISO's own March 2026 stakeholder slides said the Transition Cluster carried more than 70 GW of proposed new generation, which is more than double the state's summer peak load.

A data center isn't asking to inject anything. It wants to withdraw power, so it goes through NYISO's load interconnection procedure instead. That distinction matters for land. A parcel's value to a data center buyer depends on how fast a load can be studied and served at a nearby substation, and the size of the generator backlog doesn't tell you that. The two only overlap when a data center plans its own generation, which we cover below. For how interconnection queues work across all the major grid operators, see our general interconnection queue guide.

How NYISO studies a data center load today

NYISO published Technical Bulletin 266 in November 2025 to spell out the current load System Impact Study (SIS) procedure. Here's the sequence it describes, in order.

1. Check whether NYISO is involved at all

The NYISO procedure applies to load interconnections greater than 10 MW at 115 kV or above, or 80 MW or more below 115 kV, including uprates to existing or previously planned loads. A project under those lines goes through the connecting transmission owner (CTO) alone. So a 60 MW campus on a 69 kV line and a 60 MW campus on a 115 kV line can start down different paths.

2. Talk to the transmission owner before filing

NYISO recommends that customers coordinate with the CTO first to agree on a proposed point of interconnection (the substation or line name and its voltage) and a preliminary plan for local upgrades. In New York the transmission owners include Central Hudson, Con Edison, NYSEG, National Grid's Niagara Mohawk, Orange and Rockland, RG&E, and the New York Power Authority, with LIPA's system on Long Island. A complete request needs the interconnection request form and a conceptual one-line drawing that shows the project up to a clearly labeled point of interconnection.

3. Scoping, data, and the deposit

NYISO typically schedules a scoping call within about two weeks of deeming a request complete. Attendees need Critical Energy Infrastructure Information (CEII) access and, where required, the CTO's confidentiality agreement. Before the study is scoped, NYISO asks for the load's category (traditional data center, AI training or inference, crypto mining, and so on), how flexible it is during peak periods, daily and seasonal load profiles, phased in-service dates with MW at each phase, and power flow, dynamics, and short-circuit models. The customer has 30 days to sign the System Impact Study Agreement and must post a $150,000 deposit. NYISO refunds the difference if the study comes in under that amount and bills the overage if it runs over.

4. The study itself

The SIS uses a year-five base case drawn from a recent planning study such as NYISO's Short-Term Assessment of Reliability. Load projects in the same area and timeframe may be bundled into one post-project case so their combined impact is caught. If the study finds adverse reliability impacts, it identifies possible Network Upgrades or project changes, and it can test whether a slower ramp schedule avoids the problem before the site reaches full load. The SIS doesn't give cost or schedule estimates for upgrades. Those come later, in the CTO's facilities study.

5. Timing, and what happens next

NYISO calls nine months from study selection to SIS completion a conservative estimate, and says real timelines vary with how quickly models are validated, the size of any reliability problems, and how complex the upgrades are. The SIS is informational and non-binding. Once it's done and paid for, NYISO's role ends. The customer then does the facilities study and signs a two-party interconnection agreement with the CTO. Affected transmission owners and neighboring systems may also review the results.

Co-located and partner generation

The proposal gives a large load two ways to bring its own power. A co-located generator sits behind the same point of interconnection. A partner generator is somewhere else, but it has to be in the same capacity region and has to finish the generator interconnection process, including receiving capacity (CRIS) rights. A co-located generator that won't inject power and doesn't want ERIS or CRIS may be able to skip the Cluster Study. If it wants those rights, it still goes through the Cluster Study like any other generator.

For a landowner, that makes certain features worth more in New York: room for on-site generation, a gas lateral or a site that could support one, and room for battery storage. Our guides to behind-the-meter power and curtailment and demand response explain why a developer might accept non-firm service, and what that does to the land it needs.

What it means for a New York data center site

Voltage at the likely point of interconnection is the first thing to pin down. The current 115 kV line and the proposed 69 kV and 50 MW lines decide whether NYISO studies the project at all. A parcel next to a 115 kV or 230 kV substation will be read very differently from one that can only reach a 34.5 kV distribution feeder. If you know the nearest substation's name and voltage, put it at the top of any pitch. Our land near substations guide covers how buyers look at distance and capacity.

Geography inside the state matters too. New York prices power by zone, and downstate zones run tight and expensive. Our New York data center land page explains why upstate areas near NYPA hydropower, such as St. Lawrence County, the Niagara corridor, and Central New York, are the more realistic large-load targets. The proposed resource adequacy screen could add to that difference, since it asks whether generation is available in the load's capacity region.

Expect the developer to own the studies. The $150,000 deposit, the CEII access, and the PSS®E-level modeling are the developer's job, not yours. What you can do is make the site easy to study: clean title, a boundary survey, documented frontage on or near transmission rights-of-way, and a clear answer on how many acres are usable. The due diligence checklist lists what to gather.

Common mistakes evaluating NYISO-territory land

The most common mistake is pointing to the generator queue as evidence that a site can or can't serve a data center. More than 70 GW of proposed generation in the Transition Cluster says a lot about New York's generation pipeline and very little about whether a 100 MW load can be served at a particular substation. Those are different studies with different owners.

The second mistake is treating a finished System Impact Study as a capacity reservation. NYISO says plainly that the load SIS is informational and non-binding, and that the facilities study can use a different system model and reach different upgrade conclusions. A seller who calls a site "NYISO approved" because a past buyer finished an SIS is overstating it.

The third is assuming 2026 rules will match 2025 rules. If NYISO's Section 205 filing goes in as targeted and FERC accepts it, the size threshold, the deposit timing, and firm versus non-firm service could all change for projects that haven't reached their study yet. Date any statement you make about process, and confirm it with the transmission owner.

NYISO next to its neighbors

New York borders two other grid operators with their own large-load efforts. PJM covers New Jersey and Pennsylvania just to the south and west. ISO-NE covers New England to the east, including Massachusetts. All of them got the same June 2026 FERC show cause orders, so many large-load rules are being rewritten across the Northeast at once. Parcels a few miles apart across a state line may still face different thresholds, deposits, and timelines, so compare the specific process each one would go through.

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