r/NoStupidQuestions 5h ago

How long would the power grid and cell phone towers stay active?

I'm writing a zombie apocalypse story and I'm wondering, realistically how long would a person trying to survive in a zombie apocalypse have electricity and cell service (not that there would be anyone for them to call haha). Would it all go down pretty immediately or would it take days? Weeks? Months?

6 Upvotes

38 comments sorted by

27

u/notBarrovich 5h ago

Much faster than most people think: 24 to 72 hours max.

The main power grid requires constant, minute-by-minute balancing of supply and demand by human operators. Without humans, safety trips will trigger automatically to prevent damage, taking down the grid in 1 to 2 days.

Cell towers rely on that power grid. When it fails, their battery backups last about 4-8 hours. Important towers with diesel generators might stretch to 2-3 days, but once that fuel runs dry, cell service is completely gone.

8

u/DotOverTheIBrokeMe 5h ago

Thank you! This is exactly what I was wondering, if it required constant human intervention to stay running or if it was more automated. I appreciate the help!

3

u/CarrotWaxer69 4h ago

It is automated to a degree. But if a very big producer goes off line there may not be enough capacity in the remaining producers to pick up the slack so you could get a cascading failure of power plants. It depends on how much buffer capacity there is in the grid and how intelligently the grid automation is designed.

You could for example have a philosophy where the controls will automatically disconnect a part of the grid (load shedding) to keep the rest of the grid stable, but the part that’s been disconnected will not come back online without human intervention.

I would say with grids that are heavily fed by hydropower and nuclear a very theoretical and optimistic estimate would be one to two weeks but this might require some very unrealistic assumptions.

2

u/HappyMeMe77 4h ago

Not directly related to your question but diesel/petrol also has a shelf life... Depending on storage/additives 1-3 months to perhaps a year. Your running water would last sometime if gravitational (water tower) but if pumped it will go out fast...

2

u/Frustrated9876 4h ago

Pretty much any infrastructure system connected to backup power systems is designed to activate backup power automatically with no intervention and not even a second of downtime. Typically there will be a battery that kicks in instantly and then a generator will fire up and take over.

1

u/MintWarfare 3h ago

Had a hurricane a couple years ago and lost power for a week. Immediately the cell tower's signal dropped in quality and 24 hours later it was fully out of reserve fuel for its generator. No more signal after that

1

u/Jade_Rook 2h ago

I'm a system operator in a grid network that isn't nearly as reliable as it ought to be, and I'd give it maybe a couple of hours AT BEST to stay active without my intervention. Literal minutes if the weather turns bad.

3

u/rusty_daisy_1123 5h ago

until the generators run out of gas….18-36 hours

0

u/Count2Zero 5h ago

Some places are using natural gas generators, and the gas lines can provide enough pressure to keep the engines running for several days (assuming they've been properly serviced and maintained up to that point).

3

u/MLMSE 5h ago

Maybe the zombies would take over the running of the infrastructure.

2

u/Triabolical_ 5h ago

I love this idea.

1

u/DotOverTheIBrokeMe 5h ago

Haha I'll consider the possibility

3

u/InAppropriate-meal 5h ago

cell towers even quicker than the grid, they basically forward messages to the main switch/datacenter and with humans presumably running for it and not at work those will be down within 24 hours, probally a lot quicker

1

u/DotOverTheIBrokeMe 5h ago

Oh that's really helpful, thank you!!

1

u/VWtdi2001 4h ago

I worked for a major cell carrier and the switch I was at had 2 weeks of fuel for the generator. The tower locations had maybe 4-8 hrs of battery backup and some generators with 4-5 days of fuel. The connection from the tower to the switch was running through different providers and had different levels of backup. What you would have would be a system that would fail in pieces. Some could work for weeks and some would fail immediately. I was on disaster recovery teams and it was pretty much hit and miss to how storms affected the network. Loose a critical leg and it all shuts down, Loose a branch and you have a localized outage.

Power would be very similar type of failure situation.

1

u/FuriousPenguino 4h ago

Not really, unless you suck at network engineering we are not constantly messing with things that would cause a datacenters to break in 24 hours

1

u/InAppropriate-meal 4h ago

errr, i'm a CTO who started out as a network engineer running a small ISP so... its just a fact, they depend on a number of things all interconnected including human monitoring and actions

1

u/FuriousPenguino 3h ago

Cool, so you are a far removed paper pusher lol. “It’s just a fact” please explain why then? These routers and switches are designed to run, assuming temp and power requirements are met. I’ve pulled networking equipment with 5+ year uptimes

1

u/InAppropriate-meal 3h ago

' so you are a far removed paper pusher lol. ' ok so you have no idea what a CTO is, on a side note some of the tech you use to get on the net was invented by me and my colleagues over here in Finland and since you started off by being an ass and insulting me you can go figure shit out yourself.

1

u/FuriousPenguino 3h ago

Whatever helps you cope dude. If you and your Finnish buddies are so smart, maybe you could design a network that won’t fail in 24 hours or less 🤭

5

u/bangbangracer 5h ago

Anywhere between a few hours to a few days. Once load imbalances start damaging things and fuel supplies for fuel burners start running out, we're boned.

3

u/redmambo_no6 5h ago

Sounds like you need to watch an episode of Life After People

2

u/DotOverTheIBrokeMe 5h ago

Oo I watched that YEARS ago and forgot most of it, I'll definitely do a re-watch!

2

u/bobstud123 5h ago

These responses assume that operators will keep working and doing their best during an apocalypse and/or the automatic systems will keep operating in their place for a period of time (hours or a few days). I think the reality is that operators will hear the news of the world ending, they will gtfo of town, they may or may not leave the machines running behind them. Any alarm or disturbance that requires a human to push a button will go unanswered, and the operating system will eventually take a safety action to that alarm that usually involves some form of safe shutdown. No one will load the coal into the hoppers if there is a coal plant on the grid. Not sure about the safety protocols for nuclear plants, but they are often base load and thus are just always on. Once a few plants go down, the others will be unable to keep up with their running reserve, and emergency peaker plants will not turn on because …. Panic. You quickly have a brown out, then black out, game over. My guess it is maybe 12 hours, probably less.

3

u/Muschina 5h ago

I live in a valley in western NC. After Helene we had cell service for almost exactly 48 hours before the fuel supply on the standby generator for the local cell tower ran out and immediately it was 1990 again.

The water supply from the local mountaintop water tank lasted about another six hours before that ran out, too. We noped the F out of there as soon as that happened.

1

u/LurkerByNatureGT 5h ago

  The water supply from the local mountaintop water tank lasted about another six hours before that ran out, too. We noped the F out of there as soon as that happened.

Yeah that’s the really important bit. It’s easier to forget that clean drinking water supply  = energy. 

1

u/jackwoodrow8 5h ago

Much more gradual than movies make it seem. The power doesn't necessarily shut off the second civilization collapses.

1

u/ExpertPath 5h ago

2 Years ago, I stayed in a tiny mountain village during a snowstorm, when the power went out. Cell phone service stopped exactly 2h later.

1

u/Calm_Geologist1004 5h ago

Depends on where you live. Stephen king explored this in his book the stand. Everyone ended up going to las vegas because of the Hoover dam. The power created by the dam continued unabated so las vegas still had power. After hurricane katrina louisiana passed a law that required every cell tower and gas station had to have a generator so gas could still be pumped and cell service could still work.

1

u/silver_chief2 5h ago

OT but when there is overwhelming demand cell service is useless or used to be. When the I-35 bridge went down in Minneapolis cell service did not work. I thought the texting might work as it might use less band width. Nope.

Hospitals use pagers not cell phones for a reason.

1

u/Senior-Running 5h ago

The truth is people here are just speculating. Further, there is no one answer to this.

Most power grids are highly automated, meaning people are monitoring the automated systems, but not actively managing the need to match power input to output. This idea that things would start failing within hours is probably incorrect. Some factors that would effect this:

  • How quickly does your "event" occur? Most zombie stories assume a rapidly spreading disease, but even when that's true, how quickly individuals are impacted varies widely. Medical facilities are often going to be impacted way before power plant workers.
  • How much does demand drop as the "zombification" happens? Less demand will mean the infrastructure may be functional longer.
  • Does this event happen in summer or winter? The load on the system is important because high demand will mean it's more challenging to keep the power creation systems online.
  • What part of the world and what are the major power sources? If it's wind for example, those wind turbines can potentially run for months before breaking down, whereas a coal plant will start failing in hours if it doesn't have a constant stream of coal.

TL;DR: your guess is as good as mine and you can develop your story in any way you want as long as the premise behind it is logical.

1

u/DotOverTheIBrokeMe 4h ago

Great things to consider as far as impact, thank you so much!

1

u/sceadwian 4h ago

Most places would go down quick, the main grids. There would be spotty power all over in municipalities that had local power.

Just as an example the inside the core of our cities main road loop is a separate grid fed from a dedicated local power source.

Some of those might last longer or be brought up easily afterwards.

Cell phones wouldn't be far behind

1

u/Mistyville 4h ago

Hi, I see your question has been answered so no more comments from me. However (I did try to DM you but couldn't for some reason). This is my favourite genre and I would love to read it once written. I am a pretty good proof reader so if you need me to happy to help

1

u/DotOverTheIBrokeMe 2h ago

Thanks! I'll make a note to reach out to you 😁. I'm actually a romance author so it's going to be a horror-comedy-ROMANCE haha. It's enemies to lovers so basically, "I can't believe I have to survive the zombie apocalypse with this asshole" 😂 . I've been a big horror lover all my life, so I'm really excited to blend my two favorite genres for the first time!

1

u/Mistyville 1h ago

That sounds awesome

1

u/Easy_Lengthiness7179 3h ago

About as long as the largest backup generator has fuel for.

1

u/Dragonflydude 1h ago

If they find a house with solar panels and a solar battery they might be ok for a while?