# Electricity/ Generator/ Post-apocalypse question



## BluntAshwater

Right, this question has two separate (albeit related) prongs, so I shall ask them both in different sections.

1. Is there any part of a generator which would likely need replaced at some point during it's life cycle? I am referring to any kind of generator, none in particular. The reason I ask is I plan on using this replacement part as plot advancement. More specifically, post-apocalyptic environment, characters find a generator. One has engineering expertise. Advises that a replacement part is needed, so the group sets out to find it.

2. How long would it take after a major disaster hit (as in, most of the population of the country being incapacitated) for utilities such as power to cease?

My eternal gratitude goes to anyone who can help with either question


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## Sam

After a while, the bearings of a generator will cease to work because of disrepair or constant use. They're also very easy to replace and don't require very much technical know-how of generators to do so. 

Most major power stations (those that run cities especially) require a lot of workers to operate. Without them there to run and maintain the machinery, the plant would overload in as little as twenty-four hours, or as long as a couple of days.


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## BluntAshwater

Thank you so much, you're a star!


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## Sam

You're welcome.


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## garza

Bearings wearing out was my first though as well. Bearings are the fastest moving parts of a generator and need to be replaced regularly. 

Now if your major disaster happened to be an attack with thermonuclear weapons, about half a second would be required to paralyze a fairly wide area. And the more technologically advanced, the greater the damage.

Thermonuclear weapons produce very strong electro-magnetic pulses. Those who think about such things have suggested that the first strike by an enemy would be the detonation of a very large thermonuclear device at fairly high altitude. Power distribution substations, microwave towers including wireless telephone towers, radio and television stations, military communications networks, landline telephone systems, all would be disabled. Power plants today in developed countries are tied to complex grids that are computer controlled. Computers connected to the grids would be disabled and the power plants they control would shut down. 

All power and communications systems would shut down almost instantly.  

The only defence against such an attack is to kill the vehicle delivering the device. Once it detonates your society would be without communications and thus unable to mount any kind of co-ordinated resistance. Of course we also assume that the initial detonation at high altitude would be followed by devices detonated at lower altitude to cause physical damage on the ground.


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## gregory.k

I know this seems a little simplistic but generators don't create electricity from nothing. Whatever fuels the generator could run out or leak out. Though I'm thinking an engineer would not be needed to deal with that problem really.


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## Olly Buckle

Consider the number of people wanting power and the amount produced, if you are talking a small generator, and you have separated that part of the question from the utilities bit, them I would expect brushes on the commutator, or even the commutator itself, to go before the bearings. Industrial size generators might be a different kettle of fish, I don't know.


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## garza

Power plants use alternators so there are no brushes or commutators to wear out. 

The most vulnerable area in a modern power generating and distribution system is the control system which is all computerised now. Bearings, as mentioned, can overheat and burn out.

A majority of commercial power today is hydro or nuclear.

Edit - No, I'm wrong. Most alternators do have brushes and commutators. I'm thinking of small, special purpose alternators that have a fixed field and a rotating permanent magnet.


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## WolfieReveles

Ok, so I realize I may be bumping this thread when the thread died months ago, but for anyone writing post apocalyptic stories I recommend this recently released documentary series by History Channel: *
Life After People* Life After People &mdash; History.com TV Episodes, Schedule, & Video

Unfortunately it doesn't bode well for us wasteland/fallout/mad max fans but it's definitely worth checking out.


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## sailorguitar

I think most of our electrical power in the U.S, is coal powered, and some is hydro, solar and wind.   Do we use nuclear power generators anymore? I think coal is numero uno though.  Bearings would also be my vote for a replacement part.  There are few moving parts in a generator. Check out, "Preventative Maintenence of Eletrical Equipment," by Cahrles I. Hubert.  Also, check out "Navpers electrical"... if you google that you will get the free online book, there is a chapter on generators.  Click on "RF Cafe - Electricity - Basic Navy Training Course, Navpers 10622."  Do not use the one for Electricians Mate, the other one is better.  Hope this helps.


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## MJ Preston

gregory.k said:


> I know this seems a little simplistic but generators don't create electricity from nothing. Whatever fuels the generator could run out or leak out. Though I'm thinking an engineer would not be needed to deal with that problem really.



If it was a post apocalyptic Union Job Site a engineer would definitely be required.  Sorry couldn't resist.


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## Scarlett_156

BluntAshwater said:


> 1. Is there any part of a generator which would likely need replaced at some point during it's life cycle? I am referring to any kind of generator, none in particular. The reason I ask is I plan on using this replacement part as plot advancement. More specifically, post-apocalyptic environment, characters find a generator. One has engineering expertise. Advises that a replacement part is needed, so the group sets out to find it.



You don't say what kind of generator it is, whether it runs on gasoline or some sort of fossil-based fuel, though most generators do and so I will assume you're talking about a gas-powered generator. 

Before the machined parts--pistons, lifters, rods, bearings--wear out, other things will wear out if the generator is in constant use.  The fuel filter and fuel lines will get clogged (just like they do on your car); the intake will become choked with dirt and therefore inefficient; the spark-generating apparatus will become fouled--et cetera.  All the things that need to be replaced regularly on a car--lubricants, belts, filters --need to be replaced on a fuel-powered electric generator. Sometimes those things are pretty hard to get, too, especially after the apocalypse when zombies have chewed off the parts counter guy's head and you don't know how to read the inventory book. 



BluntAshwater said:


> 2. How long would it take after a major disaster hit (as in, most of the population of the country being incapacitated) for utilities such as power to cease?



I don't know if you have ever read _The Stand _by Stephen King or _Atlas Shrugged_ by Ayn Rand.  While neither of these writers may be your personal favorite, these books do contain pretty detailed accounts of things--all sorts of things in our civilized, mechanized world--falling apart before, during, and after a disaster.  Both were researched and are knowledgeable, reasonable accounts of post-apocalyptic scenarios. 

Generally speaking, a "major disaster" is going to knock a lot of systems offline; the times for power grids to fail in a disaster would depend on what was going on at the time.  If an area was simply evacuated or otherwise depopulated, as in a plague, and everything kept running until systems broke down from friction or ran out of juice, it might take as long as a week in some cases for electricity and water to fail.


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## garza

Modern generator systems do not use pistons, lifters, or rods. The generator is turned by a gas-fired turbine, so there are very few moving parts. As one of the first responders mentioned, bearings would be the first to go.


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## Scarlett_156

Good point.  To explain further, I was actually thinking of the emergency and outdoor-use type gas-powered generators like you would find on a large ranch or farm, not power plant generators.  The average person or group of people I'm thinking would have a really hard time keeping the typical power plant going without a lot of specialized knowledge and a fairly large crew of assistants--plus there would be some pretty fierce competition between groups of survivors (and zombies! don't forget the zombies!) to gain control of a city's power plant in the event of a disaster.  Most average survivors of a disaster would be avoiding the power plants.  Also, it's highly unlikely that a modern power plant would be completely crippled by the lack of a single part; anyone knowledgeable enough to take a stab at starting the city's generators going again would likely also know about the power plant's back-up systems.


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## plbuster

Bearings, filters, and gaskets are the least of one's worries.  Fuel is the biggest problem.  In a post apocalyptic scenario, availability of gasoline or diesel to power the generator would be the biggest hurdle to jump.
Check out Wood-gas generators, which replace the carbeurator with a wood gas generator system to power the engine.  They use wood chips, chunks, rice hulls, and any other burnable renewable source.  Lots of resources on the web, including some old FEMA plans for farmers.  Here's a link:
Wood Gas Generators | Cars | Electricity Generation


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## seigfried007

Replacement parts are a big deal, but as others have mentioned, fuel is the biggest. Some generators are very specialized and need specialized fuel (like gasoline). Without people to make and ship gasoline, your people are screwed unless they go around robbing gas stations (which will be among the first hit in an apocalypse by looters because all the smart people know that what you want most in the apocalypse are apparently gasoline and ammunition). However one can use other generators or adapt generators to accept other burnable sources of fuel (which may or may not be easy to find depending on your apocalypse), or possibly engineer ones to use solar, wind or hydro power.

A big question for you however is why is power so imperative? People existed without electric power for thousands of years; why is the power itself so important to the story?


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## Richard.E.Craig

Bearing wear on a diesel gen set engine isn't really an issue at all,as you would typically be using an engine rated to produce its top power at around 4500 RPM running at well under 2000 RPM. This means that the gen-set is designed to produce its rated Kw output at tick-over. As for replacing bearings it depends on what bearings you are talking about. Big End Bearings-Small End Bearings-Crankshaft Bearings-Camshaft Bearings, Alternator Bearings. You will need to split the engine to replace most bearings. It is still very unlikely that you will ever give a diesel gen-set much maintenance. There is a lighthouse on an island near my home. It has run on the same  diesel engine for over seventy years ( A GARDNER ). It receives a fresh oil change every two to tree years. If a power station were to find itself without a workforce, it would cease to operate in 24 hours or less.
Regards Richard


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## Ditch

Begging your pardon, but bearings are made of hardened steel. The brushes which are in constant contact with the rotating commutator are a composite of carbon or graphite bound together with resins then baked and believe me, they are the first things to wear out as_* they are made to wear.*_

We live in hurricane country and have had to depend on our generator for 6 weeks before after hurricane Rita. After a wide spread disaster, gasoline would still be around in the thousands of cars, lawn mowers and other small motors and could be scrounged as in the "Mad Max" movies. The oil does need to be changed frequently, about every 4-5 tanks of gas which would be a bigger challenge than the gasoline, you would have to break into stores and such.

Although there are gas fired turbine generators, the most commonly used ones are the old Briggs and Stratton powered ones that they sell everywhere.

But the brushes will always be the first to go, and the hardest to obtain, they have to match that particular generator.


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## Richard.E.Craig

@Ditch Hi Ditch a small Briggs & Stratton four stroke lawnmower engine is in no way comparable to a large diesel gen-set engine from a manufacturer like F.G. Wilson   using power plants from Caterpillar,Perkins or Detroit Diesel. These sets are rated at continuous load, and are run on ships 24 hours a day for months on end with the bare minimum of maintenance.
The smallest Briggs & Stratton gen set produces 800 Watts the largest produces 8000 Watts ( I got the figures from the Briggs & Stratton web site )
The smallest portable F.G. Wilson set produces 6.8 kVA ( 6800 Watts ) the largest portable set produces 2800 kVA ( 224,0000 Watts ) nearly a quarter of a million Watts! A typical hospital set will be in the region of one 2800kVA set plus another as backup.  
Another advantage of a diesel set is that it can run on vegetable oil with no modifications,you could grow your own fuel; Rapeseed for instance!
I have been building and installing diesel gen-sets for more years than I care to remember. The quality and endurance of these engines is immense. All of the Perkins sets use a Rolls Royce engine. The stator bearings on the Caterpillar are made not of hardened steel but a tungsten carbide composite plated with platinum. It should also be pointed out that most diesel sets in the 24.5 to 2800 kVA use a PMG con-tactless pick up and not brushes so contact wear isn't even an issue ! 
I have listed below the three standard gen-set configurations .
1.Standby Rating based on Applicable for supplying emergency power for the duration of normal power interruption. No sustained overload capability is available for this rating
2.Prime (Unlimited Running Time) Rating: Output available with varying load for an unlimited time. Average power output is 70% of the prime rating.
3.Base Load (Continuous) Rating based on: Applicable for supplying power continuously to a constant load up to the full output rating for unlimited hours. No sustained overload capability is available for this rating.
Regards Richard


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## Ditch

Ditch Hi Ditch a small Briggs & Stratton four stroke lawnmower  engine is in no way comparable to a large diesel gen-set engine from a  manufacturer like F.G. Wilson   using power plants from  Caterpillar,Perkins or Detroit Diesel. These sets are rated at  continuous load, and are run on ships 24 hours a day for months on end  with the bare minimum of maintenance.

All of your information is correct Richard. The problem is that most people can't come close to affording a large diesel generator that will only be used every few years for a limited time. We live on the coast and loose power regularly every hurricane season usually. The really well off have a Generac whole house generator, but they are few and far between. Most everyone has a portable generator in the 5,500 watt range and run extension cords, feed the fridge for a while, then a small AC unit, water heater for a short while. I wired an outdoor receptacle directly into the breaker box, just kill the main and flip what breakers are needed when. Keeps the mosquitoes and varmints out not leaving the door cracked.


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## Richard.E.Craig

@Ditch: I totally agree with your observations. We have a very stable climate in Northern Ireland and no tornadoes thank God they must be terrifying. On very rare  occasions we get huge devastating hurricanes..or blistering snow storms..summers are mild and damp. But Ireland is beautiful in any weather.
Regards Richard


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## Dustin Lloyd

A good research tool i used for this question was the documentary ''Life After People''. Most electricity plants would be shut down within days, but Hydro, Solar, and Wind powered electricity can go strong for a while. Don't remember how long exactly though.


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