Frequency spike in PJM (Wednesday 22nd July 2026) with sudden ~3,000MW demand drop

Social media is both a blessing and a curse (how much of one and not the other does seem to depend significantly on which platform one uses).

It was via social media that I became aware of an interesting frequency spike – with this LinkedIn update from Robert Orndorff seeming most useful:

Robert notes this happened at 11:56:24 UTC on Tuesday 22nd July 2026  … which would mean 07:56:24 local time.

1)  An initial instantaneous spike to 60.1Hz* is impressive for a grid that size, and note:

* a reminder to NEM junkies that the NEM spins at 3,000rpm (50Hz) and that North America and some other places spin at 3,600rpm (60Hz).

(a)  a second spike not far behind (presumably as some more load was lost?)

(b)  and a recovery time of ~800 seconds (or 13 minutes)

2)  In the thread underneath, there’s some speculation that it might be related to disconnection of Data Center load, but I’ve not seen anything official.

3)  Though note that Robert’s note links to the Reuters article ‘Massive disconnect of power roils largest US electric grid’ by Tim McLaughlin (I see it’s available elsewhere as well) which says:

‘The epicenter of the event was in northern Virginia, home to the largest collection of data centers in the world. When an area transmission line went out of service Wednesday morning, the data centers’ own control systems unplugged from the electric grid and transferred to backup power, Dominion Energy, the electric utility for the region, said in a statement.’

4)  But I could not find anything directly published on the Dominion Energy website.

5)  Note that Ryan Quint also provided this update on LinkedIn.

Curious to see if PJM had published anything, I took a quick look and could not see any reporting or news update – but did capture this trend of measured demand, which does show a ~3,000MW demand drop just before 08:00 local time on Tuesday 22nd July 2026:

PS1 article ‘The strongest bus on the grid just shed 3 GW. That should scare us.’ by Ali Zain Banatwala

We noted that on Friday 24th July 2026, Ali Zain Banatwala published this LinkedIn article ‘The strongest bus on the grid just shed 3 GW. That should scare us.’ that readers here should be aware of. 

The provocative title is sure to garner attention!

I’d first become aware of this when the this shorter except popped up in my feed on Friday afternoon (NEM time):