how long is the electricity going to the last post apocalypse?
October 9, 2011 10:50 PM   Subscribe

So I'm watching The Stand, and I noticed late plague, the power's still on. So how long will the power run without maintenance.

All sorts of post apocalypse movies have the power going out as part of the story. How long should that take? Dies it differ for coal, oil, hydro electric, wind, nuclear?
posted by garlic to Science & Nature (31 answers total) 8 users marked this as a favorite
 
It's been a few years since I read The Stand, but I don't think Captain Trips killed everyone. There was also the sense that the survivors were chosen by God/Mother Abigail and The Devil/Flagg, which may have implied that people who were vital to infrastructure running were still around.

If you're interested specifically in the world of The Stand, there's a story in Night Shift that revisits it, as well as some of the later Dark Tower books.
posted by Lovecraft In Brooklyn at 10:57 PM on October 9, 2011


You REALLY want Life After People to answer your question. In fact, I saw an episode that did answer all your questions.
posted by hal_c_on at 10:58 PM on October 9, 2011


The World Without Us talked about this, but I forget what the answer was, exactly. The Wiki for Aftermath: Population Zero, a documentary based on the book, offers this:

DAYS 3-7: "Security measures in power plants fail. The equipment in the spent fuel buildings adjoining nuclear power plants that maintain the temperature level of the spent nuclear fuel rods will shut down because the fossil fuel powered back up power generators will run out. At that time, the cooling pools that prevent the spent nuclear fuel from overheating will start to boil. Radioactive steam will vent into the atmosphere because the water eventually evaporates and the spent fuel would set fire to the building, causing a (non nuclear) explosion, emitting radiation not only in the immediate area of the plant but carried by winds around the globe. This is repeated dozens of times as shutdown nuclear plant spent fuel houses explode."
posted by tumid dahlia at 11:00 PM on October 9, 2011 [2 favorites]


Sorry, it also mentions that a coal-fired plant would fizzle out after a day.
posted by tumid dahlia at 11:01 PM on October 9, 2011




Best answer: The power grid has to be managed on literally a minute-to-minute basis, with power plants being brought online or shut down again, in order to match generation to consumption.

If generation runs without corresponding consumption, you get a huge rise in voltage, and distribution transformers will blow up all over the place. This destroys the distribution system beyond the ability of a post-holocaust civilization to repair it.
posted by Chocolate Pickle at 11:13 PM on October 9, 2011 [4 favorites]


The plague in The Stand moved slowly enough that I think people would be able to make plans, and I remember that the survivors were passing down knowledge. So it wouldn't be instantaneous failure.
posted by Lovecraft In Brooklyn at 11:28 PM on October 9, 2011


A pressurized water reactor would probably vary in plant temperature, with nobody controlling it by bumping rods in or out. Whether that would hit a protective action setpoint and cause a scram or something depends on a lot of things, but could take a long time.

The limiting factor would probably be fresh makeup water for the steam plant. Steam plants leak water - they're supposed to, past pump shafts and various other places. Water gets automatically added and dumped from the system as necessary from fresh water tanks, but those tanks are eventually going to be empty if nobody is making any distilled water. (I doubt commercial plants just go with tap water.)

So, steam plant runs out of water, turbines trip, no heat sink for the reactor, reactor scrams and emergency decay heat removal systems run until they're out of water, reactor heats up and vents until IT is out of water, reactor damages itself a la Three Mile Island.

How long depends on how big the tanks holding the makeup feed water are, but I'd bet not more than a day or two.
posted by ctmf at 11:43 PM on October 9, 2011


And now the follow-up question.. would a group of 10-20 survivors, unskilled but of various backgrounds, be able to get a coal plant running again and restore power to their safe house and surrounding area?
posted by Harry at 12:18 AM on October 10, 2011


@Harry
No chance in hell 10 - 20 survivors could get a coal fired plant up and running again. The survivors best chance would be to find a portable diesel generator, move it where they need it and get it running. Then the "only" problem would be finding diesel and spare parts. Mad Max, anyone?
posted by pandabearjohnson at 12:51 AM on October 10, 2011 [1 favorite]


Chocolate Pickle wrote: The power grid has to be managed on literally a minute-to-minute basis, with power plants being brought online or shut down again, in order to match generation to consumption.

It's not actually quite that bad as long as the load doesn't change drastically. That rapid change is a large part of why micromanagement is necessary. Many generation facilities have automatic load following mechanisms, such that small variations need not be accounted for. Once you get outside the limits of those systems, all bets are off, of course.

You have to remember that we had a functioning power system with basically zero automation and very little communication between different utilities (or even different generation facilities of the same utility) for over half a century, yet the power grid still worked.

Also, if the protective devices work correctly, it's likely that the whole grid wouldn't go kaput at the same time. It would break up into islands as interconnections tripped. Clearly, you're likely to be better off if your power company's generation is pretty well matched to the existing load. I guess we should hope that the apocalypse happens at night, when there's less load on the interconnections.
posted by wierdo at 3:43 AM on October 10, 2011


Remember the Northeast Blackout of 2003? That happened without a plague wiping everyone out, because of a problem with load balancing. The grid as it exists today requires active management.

I would, however, guess that it won't be very long before the grid stops requiring much active management again, as better automated control systems are put into place. Given that, if you're asking for the purposes of writing an apocalyptic novel, the answer can be pretty much whatever you need it to be. Even with automated controls, things will eventually break down and fall offline, and lines will be cut and not repaired, so smaller and larger sections of the grid will fail at different times. The speed of the apocalypse will likely also have a huge effect on how things go -- is it a slow plague such that people are actively trying to keep the grid up, or actively trying to remove themselves from the grid as time passes? Is it a fast meteor strike such that huge damage happens to the grid all at once and chaos is immediate and none of the systems are shut down properly? That'll change how things happen.
posted by jacquilynne at 4:37 AM on October 10, 2011 [1 favorite]


Best answer: Ah, I see you watched the movie, the book has a little more detail. I don't know if what you're asking is possible. King doesn't go into much detail about how Flagg's people in Vegas get things going - but he's the devil, so I guess that's a given. Once Mother Abigail's people get to Boulder, they are able to get the power back on (fortunately there were some people who knew about that stuff), and they had to form a "turning off committee" where people had to go around and turn stuff off in people's houses so the power didn't overload once they got it back on. So while I think King took some liberties in order to keep the story moving, I think he did try to address some what might really need to happen.
posted by NoraCharles at 5:28 AM on October 10, 2011 [3 favorites]


IIRC The Stand plague took time - a couple weeks or more? It would allow the engineers to make contingency plans and set their gear up optimized for the situation.
posted by Meatbomb at 7:18 AM on October 10, 2011 [1 favorite]


had to form a "turning off committee" where people had to go around and turn stuff off in people's houses so the power didn't overload once they got it back on.

IIRC, they also had problems with fires started by electrical appliances that were left on, didn't they?
posted by davey_darling at 7:35 AM on October 10, 2011


Yeah, the power going out and then getting turned back on again is a fairly significant plot thread throughout the book.
posted by restless_nomad at 8:04 AM on October 10, 2011 [1 favorite]


For similar reasons towards the end of the original Survivors there's a subplot where they have walk along the main powerlines of the country cutting off the spurs to the now unhabited cities so they will be able to get electricity up back via hydro up in Scotland.

As an aside, interestingly in a interview re the remake the producers said that according to the expects the biggest problem would be getting fresh water, the taps would run dry very quickly and bottled water would the be the premium hoarded item.
posted by fearfulsymmetry at 8:29 AM on October 10, 2011


sigh... 'experts'.
posted by fearfulsymmetry at 8:30 AM on October 10, 2011


And now the follow-up question.. would a group of 10-20 survivors, unskilled but of various backgrounds, be able to get a coal plant running again and restore power to their safe house and surrounding area?

Where would they get the coal from?
posted by Chocolate Pickle at 9:18 AM on October 10, 2011


I think the survivors could eventually get a plant back up if someone had an engineering background, preferably mechanical engineering. There would have to be operating procedures and training manuals around.

It would take a long time. First to find and study all that stuff. Then, to train some neighbors. Then, to assess startup readiness and gather materials like fuel, fresh feed water, etc.

If this is for a story, you're going to need an actual electrical worker, though. There will be breakers tripped all over, generators have to be electrically started up, etc. It's unlikely a layperson could teach himself enough to get power from the plant to the house.
posted by ctmf at 9:38 AM on October 10, 2011


There's a minimum level of fuel usage needed for a coal plant to operate. The boiler has to be heated enough for the water in it to boil. And the boiler is huge; think "olympic swimming pool full of water".

Survivors would not be able to come up with a reliable continuous supply of fuel sufficient to get such a plant working.
posted by Chocolate Pickle at 11:35 AM on October 10, 2011 [1 favorite]


The survivors best chance would be to find a portable diesel generator, move it where they need it and get it running. Then the "only" problem would be finding diesel and spare parts.

Diesel or clean cooking oil, pandabearjohnson. Assuming there are no rubber hoses in the generator, vegetable oil would run fine. And there are drums of it in almost every fast food joint - without power, getting diesel out of the ground tanks is more work.
posted by IAmBroom at 11:43 AM on October 10, 2011


Chocolate Pickle wrote: Survivors would not be able to come up with a reliable continuous supply of fuel sufficient to get such a plant working.

As was pointed out in the Snopes link, there's a fairly decent supply just sitting outside most of them. That's only good for a few months at best, though. The bigger problem with restart, as was made a plot point in the book, is that if too much stuff is turned on or the protective gear hasn't isolated the local area from the rest of the grid, your best case result in trying to start the plant back up is that the generator will trip right back offline due to underspeed. That would be a monumental waste of fuel...

If that didn't happen you'd ruin a large fraction of the connected electrical devices, which really hate AC to have the wrong frequency. Either that or the generator would blow its windings. Also not fantastic.

Were I a survivor of the zombie (or other) apocalypse and desired electricity, I'd be scavenging for solar panels and small wind turbines. I'd also be scouring Home Depot for LED bulbs and trying to find the most energy efficient lighting and/or appliances possible. (Yes, I am the asshole who will have the lights on, and will probably get shot for my trouble) And gasoline or diesel generators (diesel is better since it lasts longer in storage, but I'd use the gasoline while it was still viable since it's a use it or lose it deal) in the scenario of the rapid zombie apocalypse where the retail fuel supply had not yet been drawn down.

Many (if not most) gas stations have inlets for portable generators, so if you can get a generator and an initial supply of fuel, you can run the tank dry. Parts and consumables other than fuel for said generator would be the biggest ongoing problem, assuming the post-apocalypse scenario was more like The Stand than some zombie attack flick.
posted by wierdo at 2:04 PM on October 10, 2011


That's only good for a few months at best, though.

More like a few days.

Anthracite is about 30 gigajoules per metric tonne. If you have a 1000 megawatt coal generation plant and it's 50% efficient (and that's pretty damned good; usually they're less efficient than that) then it means it burns a tonne of coal every fifteen seconds. Running full power, the plant would consume 960 tonnes per day, or 28,800 tonnes per month.

Those kinds of plants get coal delivered weekly. (Give or take, depending on how it's delivered. A barge full of coal is about 1600 tonnes. A big freight train is maybe 13,000 tonnes.)

Now admittedly our post-holocaust survivors aren't going to be running the place full-blast. But there's a minimum level of coal consumption needed just to make the turbine start to spin, before you get any power out at all, and it's quite high. You're still going to have to run like 25% of that consumption rate just to get the water boiling.

...and how does the coal get into the furnace, anyway? Well, they use electrical conveyer belts. Where does the electricity come from to run the conveyer belt before the plant starts producing power? And there is equipment to remove the fly ash, and I think there are impellers to push air into the furnace. All of that uses electricity, too.

In the world as we know it now, the answer is that they get it off the grid. When the plant starts up, for a while it's a considerable net consumer of electricity.

You also need a lot of electricity to make the dynamos work before they can start producing power. In our world, that too comes from the grid.

In the post holocaust, forget it. There's no source. You're not going to do this with a 50 HP gasoline generator.
posted by Chocolate Pickle at 3:54 PM on October 10, 2011


Well, I'm assuming they have on-site emergency diesel generators to provide enough power to bootstrap them up to self-sustaining in an unsupported startup. Otherwise, yeah. Screwed.
posted by ctmf at 4:31 PM on October 10, 2011


And again, you'd need a real trained operator to run the electric plant. When you go to parallel your output turbine generator with the diesel, shit could get real exciting if you don't know how to match voltage, frequency, phase rotation, etc. before shutting the breaker.
posted by ctmf at 4:35 PM on October 10, 2011


If they have diesel generators which are large enough, our post holocaust survivors wouldn't bother with the coal plant at all. They'd just use those generators directly.
posted by Chocolate Pickle at 4:56 PM on October 10, 2011 [2 favorites]


Lovecraft In Brooklyn: "It's been a few years since I read The Stand, but I don't think Captain Trips killed everyone."

99.4% of the world's population.

Lovecraft In Brooklyn: "The plague in The Stand moved slowly enough that I think people would be able to make plans, and I remember that the survivors were passing down knowledge. So it wouldn't be instantaneous failure."

I think it was about three weeks from initial escape of the virus to all non-immune people dead.
posted by Chrysostom at 6:21 PM on October 10, 2011 [1 favorite]


It may APPEAR that I'm wrong, but the error is actually because I fell through a thinny from a universe where The Stand was subtly different.
posted by Lovecraft In Brooklyn at 6:23 PM on October 10, 2011 [1 favorite]


Regarding that pile of coal outside of power plant...Can you imagine the war that will be fought for that in the post-apocalypse? First, some locals are going to realize there is free coal that they could use for cooking and heating, then a local thug will have enough savvy to martial a little militia to guard the coal and ration it. Its easy to see how human nature will will come out in all its ugly glory in the post-apocalypse. All those guns on the walls at your local Sportsman's Warehouse? They are going to get snapped up pretty quick. I've never read The Stand, does King cover this aspect of human nature? Or does he leave that for Cormac McCarthy?
posted by pandabearjohnson at 9:39 PM on October 10, 2011



Regarding that pile of coal outside of power plant...Can you imagine the war that will be fought for that in the post-apocalypse? First, some locals are going to realize there is free coal that they could use for cooking and heating, then a local thug will have enough savvy to martial a little militia to guard the coal and ration it. Its easy to see how human nature will will come out in all its ugly glory in the post-apocalypse. All those guns on the walls at your local Sportsman's Warehouse? They are going to get snapped up pretty quick. I've never read The Stand, does King cover this aspect of human nature? Or does he leave that for Cormac McCarthy?


He uses it in the Stand, and from plot summaries he uses it in The Mist and in his novelization of The Simpsons' Movie.
posted by Lovecraft In Brooklyn at 9:48 PM on October 10, 2011


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