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by onionisafruit 16 days ago
I’m curious how this works for other large consumers. Do they have some kind of artificial load that lets them gradually reduce consumption instead of doing it all at once?
2 comments

If you're large enough your connection to the grid is a negotiation with an engineering team.

The utility will force you to put equipment to correct for power factor (massive capacitor bank), resistive load, etc.

The utility also charges commercial users for apparent power (includes reactive power, or that sloshes around setting up a steady state), as opposed to just real power charged to residential users.

EDIT: in case your wondering, yes resistor loads is just glorified bunch of short circuits and a fan.

That’s interesting. For the rest of us I guess it’s just the law if large numbers that our air conditioners don’t cycle off at the same time
In the UK we have that scenario with people turning on kettles during breaks in TV programs.

https://en.wikipedia.org/wiki/TV_pickup

With the obligatory, must see, BBC Britain from Above segment in which Andrew Marr fly on the wall narrates the most challenging part of a live load engineer (UK)'s day ... <doof, doof, doof> the East Enders kettle break.

* https://www.youtube.com/watch?v=slDAvewWfrA

Pretty much. Except the law of large numbers breaks down in correlated events.

Like a black out.

What really hurts is are all the rotating machines, especially the one-phase ones (fridge, AC, blower). Those have transients that last several cycles and are electrical shorts until the back emf is setup.

Utilities will try to roll the power back on in sections to avoid instability, starting with hospitals and those near hydro plants.

But you can help put by turning off your stuff during the blackout and when the light come back on walking around the house to turn them back on.

No. I imagine they are less sensitive and generally stay online and are only de-energized if the utility has an outage
But they can have their own internal fault and have to shutdown.
A single ~50MW facility dropping off the grid suddenly is something the grid can absorb fine.

The problem is with facility-level grid-responsive safety mechanisms. If the grid sags a bit and several DCs ~simultaneously disconnect, you have a problem. If the DCs going offline causes further instability that causes other facilities to disconnect or grid protection breakers to open, you have a cascading chain reaction