Washington Has Let PJM Switch Data Centers to Backup Generators Four Times This Year. Nobody's Had to Flip the Switch Yet.

For about 30 hours this week, whether the lights stayed on for 65 million people across 13 states, from Chicago to Washington, D.C., partly depended on whether a few hundred backup generators parked behind data centers, factories, and office parks in Virginia, Ohio, and New Jersey would have to switch on. They didn't, as far as anyone has reported. That's the fourth time this year PJM Interconnection, the grid operator for the busiest data center market in the country, has asked the federal government for the authority to make it happen anyway, and the fourth time it hasn't had to use it.

What Washington actually signed off on

On October 12th, Energy Secretary Chris Wright issued Order No. 202-26-50 under Section 202(c) of the Federal Power Act, effective October 13th through the 16th. PJM had asked for it the day before, telling DOE it expected demand to hit roughly 111,500 megawatts on Tuesday, its reserve margin to come within 900 megawatts of the legal minimum on Wednesday, and about 61,591 megawatts of generating capacity to be offline for routine fall maintenance at the same time. The order lets PJM direct backup generation resources, including the generators data centers and other large industrial and commercial customers keep on-site, to run as a last resort, either just before or during a Level 3 Energy Emergency Alert, the stage where PJM can start cutting firm load. Hospitals, 911 centers, water and wastewater plants, air traffic control, and defense facilities are carved out; their backup systems stay off the table no matter what. PJM has to report back to DOE every day on which covered resources actually ran.

While past leaders' energy subtraction policies have made the grid more vulnerable to the risk of blackouts when the sun doesn't shine or the wind doesn't blow, this administration remains committed to using every available tool to prevent blackouts.Chris Wright, U.S. Secretary of Energy

By Wednesday afternoon, the emergency had already passed. PJM had issued a Capacity Advisory, a Maximum Generation Alert, and a Load Management Alert for Tuesday, extended the Maximum Generation Alert into Wednesday, and called on demand response. Then it recalled the alerts around noon Wednesday as conditions eased. DOE says there's roughly 35 gigawatts of unused backup generation sitting idle nationwide that orders like this one could tap. None of it, as far as any public reporting shows, actually had to run this week. The order stays technically live through Friday, but the number that mattered, PJM's reserve margin, pulled back from the edge before anyone's diesel tanks got tested.

This is the fourth time, not the first

DOE issued the same kind of order to PJM on January 26th (Order No. 202-26-06, later extended into February), again on May 18th (202-26-23), again on September 17th (202-26-45, which only ran about a day), and now this week. The stated trigger changes with the season: cold in January, heat in May, fall maintenance and planned outages this week. The pattern underneath it doesn't change: PJM's reserve margins keep running close enough to the edge that the federal government keeps reaching for the same backstop. NOTUS has tallied at least six of these orders issued since May alone, across PJM and the Southwest Power Pool combined, and reports that grid operators still haven't actually had to use the authority. A separate account from this summer has PJM telling large customers in July to be ready to switch to backup power within 15 minutes, and then not needing them to.

DOE reached for the same emergency authority in January for Duke Energy Carolinas, Duke Energy Progress, and ERCOT, not just PJM. A tool Section 202(c) was written for genuine, unexpected emergencies is turning into a standing instrument regulators reach for every few months as a matter of course. I think that's the real story buried under this week's order, more than the order itself: the backstop keeps getting invoked, and keeps not getting used, which is either proof the system has more slack in it than the forecasts suggest, or proof nobody wants to find out what happens the one time it doesn't.

The part a diligence file should actually check

Here's where this stops being a Washington story and starts being a site-level one. PJM's demand forecasts tie directly to data center load, and the backup generation this order counts on sits behind the meter at the same campuses driving that demand. But a facility's on-site generators usually aren't a blank check. State air permits typically cap how many hours a year an emergency generator can run outside of testing, and those caps were written around genuine emergencies and routine maintenance tests, not open-ended federal demand-response calls that can be reissued every few weeks. Whether a specific site's air permit actually allows its backup fleet to run under a DOE 202(c) order, for how many hours, and whether that use counts against the same annual cap as an actual local outage, is exactly the kind of parcel-specific, agency-confirmed fact the Kill Test is built to chase down, not assume. A developer's pitch deck says backup power exists. The permit says what it's legally allowed to do.

This week's order expires Friday whether or not PJM ever pulls the trigger on it, the same way the last three did. Take that as good news, not as proof the problem is solved. FERC spent part of October 9th telling PJM it doesn't get to decide, on its own authority, which large loads get cut first in a real emergency, and that question is still sitting with state legislatures, not settled. Until it's settled, Washington is filling the gap with three- and four-day emergency orders instead of a permanent rule, and asking the grid to hold together in the meantime. It has, four times running. That isn't the same as having fixed anything.