Thread: Electricity/ Generator/ Post-apocalypse question

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

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.

Thank you so much, you're a star!

You're welcome.

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.

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. (:

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.

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.

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 — 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.

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.

Originally Posted by 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. (:

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

Originally Posted by BluntAshwater

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.

Originally Posted by BluntAshwater

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.

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.

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.

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