The scenario is that it is a post apocalyptic world where the most of the humans have been eradicated and the sources of energy have been completely depleted. In this scenario, people discover an alien artifact which would be the solution to their problems but the problem is that to open it, they would require a huge amount of energy (kinda like overloading it, it's the property of the artifact).

Now my problem is finding that power source to generate an ungodly amount of energy and also justifying that it is a one time thing (even unreliable)... Otherwise it would be the solution to their energy problems.

Extra info: the survivors all live in a specially created city. The earth's crust has been rendered unstable and flash earthquakes, lateral spreading and volcanic eruptions are quite common.

  • $\begingroup$ Which kind of energy? The atomic bomb of celtschk provides "a lot" of energy, but in termal/pressure form. If you want "electricity", write it down. Also, what is "a lot"? $\endgroup$
    – SJuan76
    Mar 15, 2015 at 12:42
  • $\begingroup$ @SJuan76: When we think of energy, generally we think of electricity... But that need not be the only form. Energy in any form would be acceptable as long as it does not run the risk of destroying the device. For e.g. the thermal energy from the nuclear bomb could be absorbed but the pressure cannot and it could harm the device. Correct me if I am wrong. $\endgroup$
    – user96551
    Mar 17, 2015 at 2:47
  • $\begingroup$ As you are the one defining the scenario, it is not a question of wrong or right, but precise or imprecise. And to add to that, maybe you mean "power" instead of "energy". Given enough time and workers, you can produce the same energy with a few handcranks than with an atomic bomb... of course, with the bomb you deliver the energy faster. $\endgroup$
    – SJuan76
    Mar 17, 2015 at 10:50
  • $\begingroup$ A defined amount of energy is needed to make answer anything but opinion. Some conditions would also help, such as can they simply push it into a volcano? $\endgroup$
    – John
    Jul 22, 2018 at 6:17

6 Answers 6


Use a nuclear fission powerplant with broken safety

An old nuclear power plant minus all the safety features that keep it from melting down. You can probably fire it up and keep it running for a few minutes before it inevitably explodes. As long as enough of the electric net is available or temporarily repaired, you could transfer the energy outside of the meltdown radius to boot up the artefact. After that, the entire area surrounding the plant will turn into a no-go zone and the powerplant will be rendered useless.

A nuclear powerplant with the safety features destroyed does not require any outside influence to destroy, it will quickly overheat and have a catastrophic meltdown. A nuclear fission reaction will naturally spiral out of control and destroy the entire powerplant unless security features are in check. This is what makes them so dangerous and why many people are opposed to them.

How nuclear fission works

A short and basic explanation of the workings of a reactor: at the core, a nuclear fission plant contains a large amount of radioactive material. Radioactive material undergoes a powerful reaction that creates lots of energy when you bombard it with small particles. However, the reaction that generates the energy also creates more of the particles that sustain the reaction, at a better than 1:1 ratio. This means that, uncontrolled, the reaction will go faster and faster, producing more and more energy, until the plant will be unable to control all of the energy being produced and has what is called a "meltdown", at which point the powerplant is destroyed and the radioactive material is spread far and wide. This radioactive material is harmful to life and sent out in such large quantities that the site of the meltdown will be rendered uninhabitable for decades. (There was a meltdown at Chernobyl around the time I was born; I'm nearing my 30s and the area is still uninhabitable)

What a nuclear fission powerplant does is try to sustain the reaction over a long period of time by absorbing the generated particles that would make the reaction spiral out of control back into harmless material. This is done through what are called "control rods", which absorb the same particles that the radioactive material does, but not doing anything with them.

As long as the control rods work; the energy produced by the nuclear fission plant is fairly constant and maintainable. If the control rods fail, horrible, horrible things will happen. If you fire up a nuclear fission plant with broken control rods, no external influence is neccesary; the powerplant will destroy itself. This is why many people are opposed to nuclear fission; if anything goes wrong, rather than the reaction failing, it will destroy itself catasthrophically.

This is why I suggested a nuclear plant rather than a coal or solar plant; nuclear plants will always fail spectacularly, and most of the design of the facility is not dedicated to producing energy but to keep it from exploding.

For more information on how nuclear fission works, read up here: http://www.atomicarchive.com/Fission/Fission1.shtml

It explains the difference between nuclear powerplants and nuclear bombs, and you'll see that the only difference is that the power plant is trying to control the natural thing that would happen if you allowed radioactive material to react to particles; while an atomic bomb doesn't.

Bonus feature: you'll either need some (temporary) fast transportation to get the people who boot the powerplant the hell out as soon as it starts pumping, or you'll need to draw straws for who gets to stare a meltdown in the face.

  • $\begingroup$ Yes Erik, this was the only viable solution i could think of. I had decided that I would have the plant located on one of the lateral spreads and once the experiment was done, have it destroyed in a freak earthquake but then decided that it would perhaps be a bit hard to digest for the readers and decided against it... But I guess there is no other option... $\endgroup$
    – user96551
    Mar 17, 2015 at 2:57
  • $\begingroup$ I have added in a segment explaining the workings of nuclear fission. Unlike other types of powerplants, a nuclear fission without safety features works for a short time and then fails catastrophically simply because of the way it works. If the control rods are broken, your story will not require an earthquake; the physics involved in nuclear reactions will cause the powerplant to be destroyed after a short while of producing power. $\endgroup$
    – Erik
    Mar 17, 2015 at 8:35
  • $\begingroup$ Actually, nuclear power plants are quite a lot different to nuclear bombs. For one thing, the fuel is not enriched to anywhere near the levels needed for a bomb; also, a bomb requires a sudden massive input of neutrons to set it off all at once, provided by something called an initiator, which nuclear plants take great pains not to include in their designs. A reactor left to melt down would burn down the building it was in (and produce a lot of toxic waste) but that's about it. Nuclear power plants are physically incapable of producing what we think of as a nuclear explosion. $\endgroup$
    – bobtato
    May 3, 2015 at 0:45

There are many one-time energy sources around: They are called bombs.

So maybe there's a leftover nuclear bomb around. People would naturally not normally want to trigger it. However, if it is the only way to open that alien construct, and can be done at a safe distance (say, the alien construct is on an island far away, so the bomb can be transported there and then detonated after leavinf the island, possibly using a sort of improvised timer), then it would make sense to use it.

It's obvious that you cannot use the same nuclear bomb a second time. And there may not be any further nuclear bombs around (if your post apocalyptic scenario is due to a nuclear war, it's likely because all others have detonated in the war).

  • $\begingroup$ But using a bomb, let alone a nuclear bomb runs the risk of breaking the thing... What is required is feeding it with so much energy that it overload itself... I don't think bombs work that way!!! $\endgroup$
    – user96551
    Mar 15, 2015 at 9:03

I like user2448131's idea, but it can be improved.

I am assuming that what you say "source of energy" you mean electrical energy. If not, please expand on just what you do mean.

So, I'm thinking a version of Ben Franklin's (probably fictional) experiment, in one of two forms. Both involve lifting a copper wire into the path of a thunderstorm.

Going with the old traditional route, a kite or series of kites (copper wire is heavy) get launched at the height of the storm.

For something with a bit more pizazz, small rockets are used.

Each has a drawback. The kite scheme is at the mercy of the winds to get the wire right up into the storm.

The rocket idea has a problem that may not be obvious: getting the wire to pay out at high speed without snagging, but it allows launch at just the right time and direction.

You could have your protagonist try both approaches: first the kite, then the rockets when the kites don't work, or vice versa.

Both approaches do have the problem that you need a bloody thick wire to conduct the current involved without exploding.

Also to be considered is that as the wire is being lifted, it must be live - that is, it must be connected to the alien power source.

  • $\begingroup$ Actually, you don't need a thick wire; the lightning would turn a thin wire to plasma, which still conducts the lightning to the required point. $\endgroup$
    – Monty Wild
    Mar 16, 2015 at 21:53
  • $\begingroup$ Thank you for the answer, I had considered this option earlier but using this answer brought up the question that if they could generate electricity this way why rely on that possibly dangerous Allen technology... Why not just create more of the above infrastructure... It has to be a one time thing... $\endgroup$
    – user96551
    Mar 17, 2015 at 2:51
  • $\begingroup$ Well, how about the fact that a) thunderstorms are unpredictable, so they cannot be counted on to hit when you need them and b) the power levels associated with a lightning strike are so high that making a lightning collector is (practically speaking) impossible. $\endgroup$ Mar 17, 2015 at 3:04
  • $\begingroup$ @user96551 - I did a little research on the web, and you might find this interesting realclearscience.com/blog/2012/05/… Among other things, the average American home would need to be hit 40 times per day, and the entire global lighting energy is sufficient to run a total of 8% of American households. $\endgroup$ Mar 18, 2015 at 19:51

Emergency diesel generators

Hospitals, internet data centers and various other critical infrastructure buildings are equipped with diesel generators they use in case of a power-outage. These allow the building to keep working through temporary lack of electricity and keep all critical systems online.

However, they use a lot of fuel and resupplying them is a logistical nightmare. In a post apocalyptic world, they will all be empty (they would have kicked in automatically and then run until out of diesel) but they will probably still work.

These devices use in the order of 10.000 gallons of diesel for 24 hours and supply enough power to run every critical system in a hospital or thousands of computers and security systems; a lot of energy. However, finding 10.000 gallons of diesel (or even a fraction of it) in a post apocalyptic world is no easy feat.

The only reasonable way would be to try and get your hands on a fully loaded fueltruck, somehow get it to the building (probably a very dangerous trip) and then pump the fuel into the generator. Then you can have power for a few hours. Enough to work on the device. Not enough for a permanent fix.

However, if used sparingly and on a smaller generator, it is also enough to have light and some powertools in a small village. This probably means most immediately available fuel is already used up, so getting your hands on a few thousand gallons will be really difficult and it will be an incredibly valuable resource. Expect everyone you meet to be interested in taking it from you before you reach the hospital/data center.


What you need is a bank of ultracapacitors:

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A bunch of those and you get a way to discharge large ammounts of energy in a short time span. Energy versus time equals power. Charge the bank with a diesel generator across a current limiting resistor (lets say a lamp) and a diode, then discharge it on the device with no resistors to hinder current. The low ESR of the bank, coupled to its very high capacitance means that it can zap large ammounts of electrons in short time. This allows to do things like railguns or EMP bombs, and should present no harm to the device you intend to open, provided that it is designed with this use in mind. In your story, characters might scavenge ultracapaciors from modern/modernized electrical TRAMS, where they are used in the regenerative breaking system.

  • To get fuel for the generators you might run them on straight vegetable oil (SVO).
  • To get vegetable oil, you might refine various kinds of plants that can be found in the wild.
  • Its a one time thing in the sense that the logistics is so complex that it can only be done under the most urgent circunstances and you can only get a short supply of ultracapacitors due to the fact that they cant be built anymore.

Magnetohydrodynamic (MHD) generators

Magnetohydrodynamic (MHD) generators would do the trick - specifically, those of the 'pulsed power' variety.

MHD generators are 'fluid dynamos'. They harvest electrical energy from the movement of an ionic fluid through a magnetic field. There has been some interest over the years in using these to 'top' thermal (and particularly nuclear) stationary power infrastructure, for a major boost to plant efficiency.

But during the Cold War, the Soviets (in particular) had an interest in 'pulsed power' MHD generation for powering laser weapons - and, later, geomagnetic surveys - by using solid-fuel rocket motors exhausting through a solenoid. The high-temperature rocket exhaust produces a thermal plasma, which is then harvested by the coil, producing a massive pulse of electrical power: one such system, the Khibiny MHD generator, produced a 60 megawatt (MW) pulse for seven seconds. (Source: EIR Science & Technology (1995) MHD pulsed power for geophysical research)

The best thing about these systems, for your purposes, is that they are (somewhat) portable, disposable, and single use - not only are solid-fuel rockets typically single use devices, but the MHD generator is itself uncooled, and tends to end up as a pile of slag once the rocket burns out.


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