[jeffbee]

Do grid operators really have controls at that level? In California they can shut off a substation or not, and that's as low as they can go except in the special case of industrial customers with demand-responsive equipment installed. If those empty skyscrapers were on the same local circuits as a hospital, perhaps it simply wasn't possible for the electric company to turn them off.

[sbierwagen]

Around 2010 or so I worked for a skyscraper in downtown Seattle. There was a heat wave and the utility needed to shed load. The mechanism for doing that was someone calling our front desk and saying "Hello, please shut off your lights."

(Commercial lighting runs at 277v, so it's all on separate circuits from wall outlets. You can shut off the lights in a building without killing the servers, for example)

We had remote-controlled breakers, so doing that was a couple clicks of the mouse. But if nobody had picked up the phone, they would have needed cops to break into the electrical room on each floor and start flipping breakers by hand.

[brundolf]

It's more that they needed to communicate with the owners of the buildings to shut off massive systems that weren't even being used, while the minority of residents who still have power are being asked to "live as if we didn't" and navigate by candlelight, etc.

[theshrike79]

If the grid operator has deployed modern Smart Meters to their customers, they can control and measure electricity to the house level remotely.