Federal regulators told all six US grid operators to rewrite the rules for their biggest customers. PJM answered first, and its answer makes AI data center power conditional on new supply the turbine market can’t deliver in time.
When the power grid runs short, somebody has to use less. PJM runs the grid for 67 million Americans, and it has proposed that AI data center power go first in line to cut back, ahead of the factories and businesses it currently pays to power down.
There’s a way out of the queue. Build your own power supply.
But it has to be newly built, and proved by March 2027. GE Vernova’s gas turbine slots are already booked through 2031. That’s the shape of AI data center power now: something you prove before you’re allowed to depend on it.
PJM Put New Large Loads Second
The threshold is 50 megawatts at one site, roughly a mid-sized data center campus. Anything that big without its own power lands on what PJM calls “interim service”. Interim means you go first when the grid is tight.
It isn’t a blanket switch-off, and the distinction matters more than it sounds. PJM cuts only the megawatts it actually needs, only in the zone where the shortage is, and only while it lasts. What tells you where you really sit is what you get paid: everyone else who cuts back earns the full rate, interim service earns half, and PJM suggests you might like to waive even that.
PJM has a reason for all of it. It runs an auction to buy the spare capacity it will need years ahead, and the last one hit its price ceiling and still came up 6,831 megawatts short, the second auction in a row to miss.
I argued in June that Big Tech fears waiting in line more than it fears the bill. This is that fear written into a tariff.
AI Data Center Power Must Prove Its Supply
PJM will accept more than a new gas plant. Upgrading an existing plant counts. So does restarting a retired one. A customer can also qualify by agreeing to cut demand when asked. What doesn’t count is buying somebody else’s existing power. That is the rule in one line: the electricity must be new to the grid, not just new to you.
So the problem was never that power doesn’t exist. The problem is that it has to be new, and new on a calendar. Evidence is due March 1, final verification April 1, service June 1, 2027. That calendar is where I’d spend my attention if I ran one of these projects, because what I’ve seen is that project teams fix on the service date and never notice the proof date sitting three months in front of it.
Two of the routes PJM allows take far longer than either date. Gas turbines are the obvious one, with GE Vernova’s backlog reaching 116 gigawatts this summer. Connecting a new plant to the grid is slower still: for half of all projects it now takes more than five years, and of everything that joined those queues between 2000 and 2020, only 13% was running by the end of 2025. Building on site can dodge that queue, which is much of its appeal and why counting transformers beats counting chips as a way to read this buildout.
Nobody here is banning data centers. Firm power is just becoming something you bring with you, and it has to be new.
FERC Ordered Every US Grid To Do The Same
PJM didn’t decide this on its own. On June 18 federal regulators ordered all six of America’s regional grid operators to justify their rules for connecting very large customers, or rewrite them. They got sixty days. Sixty days from June 18 is the middle of August. PJM filed on August 13.
The same order sits with the operators covering the Midwest, the Plains, California, New England and New York, which makes PJM’s filing a preview rather than an exception. Texas didn’t even need the order. It runs its own grid, outside federal reach, and it moved anyway. On August 3 it froze its queue and ordered an audit of 250 to 300 projects that together want 200 gigawatts, more than double the most electricity Texas has ever used at once.
PJM’s defense is straightforward, and it’s a good one. Interim service lets you connect now instead of waiting years for power that doesn’t exist yet, and you only get cut during real shortages. For a developer staring at a queue, that’s a trade, not a punishment.
It’s also a swap. You get in sooner, and you carry the risk of being cut until you deliver the new power PJM wants, on PJM’s schedule.
Everyone Is Watching June. March Is The Deadline.
So if your AI data center power plan puts a 50-megawatt site into service after June 2027, the question isn’t whether you can buy electricity. It’s whether what you’ve lined up counts as new, and who inside your company owns the March deadline.
Nobody owns it by default, and nothing is going to move it. The pressure runs one way: Virginia’s data center tax was the same fear arriving through a legislature instead of a grid operator. March 1 needs an owner. Make sure it has one.
