Every site tour ends with the same number. “We’ll be energized in Q3 2027.” Ask what that number rests on and you get one of six answers, and only the last two of the six are worth putting in a model.
Here is the ladder, weakest first.
A verbal from the developer. Someone at the utility said there’s capacity in the area. No paper, no docket, no name. This is the most common form of evidence in the market and it’s worth nothing. Capacity in the area is not capacity at your meter.
A capacity availability or will-serve letter. Now you have paper. Read what it actually says. Most of these letters confirm that the utility believes it can serve a load of stated size at a stated location, subject to study, subject to upgrades, subject to cost allocation, and subject to whatever the tariff says on the day. None of that commits anyone to a date. A will-serve letter tells you the utility isn’t saying no, which is worth having on file when you go to the next stage. It is not a schedule and no lender will read it as one.
Seventeen acquisitions in, I’ve read a lot of these letters, and the gap between what a seller says the letter means and what the letter actually says is where most of the surprises in a diligence process come from.
A completed system impact study. Real engineering. The utility has modeled your load against the network and knows what breaks. You now have a list of required upgrades. No price and no schedule yet, but you know the shape of the problem, and whether the answer is a breaker or a new 345 kV line.
A facilities study with cost allocation. Price and scope. This is where deals die, because the number that comes back is often a multiple of what the pro forma assumed and the tariff usually puts it on you rather than the ratepayer. Getting to this stage before you close rather than after is the difference between negotiating the number and absorbing it.
An executed interconnection or electric service agreement. Signed, with milestone dates, a security deposit, and consequences running both ways. This is the first document on the ladder that a lender will underwrite as a date rather than as an intention.
Long-lead equipment on order, with a PO and a manufacturer’s slot. The agreement sets a date and the equipment determines whether that date is achievable, so the two have to be checked together.
The equipment is the schedule now
Substation-class transformers in the 5 to 50 MVA range are running 75 to 110 weeks. Generator step-up units above 50 MVA run 100 to 150 and up. Medium-voltage switchgear is 52 to 80 weeks for standard 15 kV, and 78 to 104 for 38 kV specialty gear. Terrapin Construction Group, working from live 2026 manufacturer reservations, puts today’s lead times at roughly 2.5 times pre-pandemic.
Run that against a Q3 2027 energization. That’s under 100 weeks from today, so a 5 to 50 MVA transformer ordered this month arrives with roughly no margin, and one that hasn’t been ordered arrives late.
The useful question on a site tour is whether you can see the purchase order and the manufacturer’s confirmed slot, because that is the piece of the schedule nobody can accelerate later.
The rulebook is open
On June 18, 2026, FERC issued Section 206 show cause orders to all six RTOs and ISOs, PJM, MISO, SPP, CAISO, ISO-NE and NYISO, docketed EL26-67 through EL26-72. Responses were due August 17. FERC named five things it wants addressed: the study process for large load transmission service, cost transparency and protection against cost shifting, co-location rates and terms, service for flexible loads and behind-the-meter generation, and terms for interconnection customers serving electrically proximate large loads.
Six proceedings, not one national rule. So the answer to “how does a large load get in the queue” is about to be six different answers, and which one applies to your site depends on which market it sits in. A position that looks strong under PJM practice today may look different in a year.
If you’re signing a lease or buying a site with an energization date written into it, that date depends on a rulebook that is currently open for revision, so the contract should carry a remedy for the case where the rules change and the date moves with them.
Five documents, in order
Ask for the letter. Then the system impact study, then the executed agreement with its milestone schedule, then the PO on the transformer and the switchgear with a confirmed slot. Last, establish in writing who absorbs the cost if the upgrade estimate moves between the system impact study and the facilities study.
Five documents. A site that can produce all five has a date you can put in a model. A site that can produce two is selling you a probability, which is a legitimate thing to buy at the right price and a bad thing to buy at the wrong one.
Most shortlists never separate the two. That is the whole reason sites that look identical on a spreadsheet come in eighteen months apart.
Sources
- Federal Energy Regulatory Commission, Section 206 show cause orders on large load interconnection, issued June 18, 2026. Dockets EL26-67 (PJM), EL26-68 (SPP), EL26-69 (NYISO), EL26-70 (MISO), EL26-71 (CAISO), EL26-72 (ISO-NE). RTO/ISO responses due August 17, 2026.
- Terrapin Construction Group, switchgear, transformer and generator lead times, 2026, from active manufacturer reservations.
Related: Colocation, retrofit, or development: how to choose, and how we run a site screen.