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larsattacks94 OP t1_itnflxr wrote

Reply to comment by kinyutaka in eli5: how long would power stay on if the power company abandoned their post? by larsattacks94

A week really? That is surprising. In the book they say it was day 20 when the lights go out. Thought it seemed so short but seems like they over did it

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CrossP t1_itngxtj wrote

It probably depends a bit on the kind of plant. Like if it's coal, it has to keep being moved into the furnaces. Not necessarily daily, but they get deliveries and refill the setup from storage pretty regularly. Something without fuel like wind, hydro, or solar would probably go until some piece of maintenance isn't performed.

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tarkinlarson t1_itnjw37 wrote

I heard thag nuclear would autoshutdown, but something like hoover damn would carry on until the turbines physically broke, so could be decades before a cstestrophic failure.

There are a few documentaries on it like if humans suddenly disappeared.

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CrossP t1_itnlbuv wrote

The turbines in a hydroelectric dam station would probably go for a long time, but the connection to the actual grid may not be so robust. Wires. Transformers. Lubes. Coolants. Connectors. There's always something that can break or run out. The systems are usually made to make this work simple, but there still has to be someone who checks the readings, and replace stuff or some critical bit will stop the electricity from working correctly.

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685327594 t1_itnl2b7 wrote

That's wrong on multiple levels. First off the units WOULD trip offline and second if they didn't they would physically break as soon as the grid went down because there would be no load on the generators.

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immibis t1_ito4cvu wrote

Wouldn't there be a control system that would reduce the water flow to prevent the turbines going faster than normal?

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soniclettuce t1_itoanwk wrote

There's been previous reddit threads where nuclear operators have said that current plants are generally not "walk-away safe". They claimed you'd have about a week before they'd be in danger of meltdown.

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usrevenge t1_itnm14g wrote

It would probably be a few hours tbh.

The grid has to be balanced. If your town starts using more power a power plant somewhere in the network has to spool up more generators or increase their speed.

If a power plant suddenly goes offline the power plant has to call the regional area offices and tell them so they can balance the load. I've been in a plant where this was happening a lot. Even if this wasn't automated it could easily fail somewhere. The electric grid is one of the most complicated pieces of infrastructure in the country.

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kinyutaka t1_itngebh wrote

To be fair, I am not an expert on these matters. I would be surprised if it goes for a week, because our power grid died without the abandon ship just because it was too cold.

I would call it "believable"for 20 days, I just expect less.

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685327594 t1_itnh85p wrote

No, that's completely unbelievable.

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kinyutaka t1_itnifka wrote

I am sure it depends on a lot of factors.

Some plants might go down in a heartbeat. Some might coast a bit. Like the Hoover Dam Hydroelectric Plant probably can run for a bit, especially since electrical demand would go down after an apocalypse.

I do not want to test that, though.

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685327594 t1_itninez wrote

Demand going down is bad too. The plants will trip offline either way.

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Maeghkor t1_itnjhpi wrote

Care to explain whys that?

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685327594 t1_itnk9we wrote

Without any load the turbines will start to accelerate. The protection systems will automatically trip the plant offline before it accelerates out of control and destroys itself.

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immibis t1_ito4mmz wrote

Is it not remotely possible that the load drops at a reasonable rate which the control system can cope with, ending with the dam powering just its own local area from a trickle of water?

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khalcyon2011 t1_itnlfqb wrote

Basically, the power has to go somewhere, so if demand drops, the system cycles off. I imagine it's automated, but starts and stops are wear and tear on the system. And things might get gummed woke it's down. Further, the start up systems need power, so there's another point of failure.

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wintermute93 t1_itnxm06 wrote

If you want a nonfiction account of events would likely proceed if the grid suffered massive widespread failure, read "Lights Out" by Ted Koppel.

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