Hia, I was wondering how warfare, tactics and strategies would change if energy sources were varying greatly over a single day. Especially modern, contemporary wars, since they have much more energy pulsed into them.

Since it's very generic, I will focus on a more specific instance. And also, to avoid confusions with the general word energy, I'll use the word Cyclenergy when talking about... The cyclic energy :p. Here goes nothing !

EDIT : As requested in comment, this question will focus only on direct, open confrontations and especially weaponry. If communications can affect answers, it is not the main topic.

World context

I don't really care about the world, so we'll keep it as a side dish. To keep things simple and have an element of comparison, we'll do like this : The world containing Cyclenergy would be like Earth, around the late 20th to today science and knowledge-wise, and with around the same organisation, politically, geographically, culture... People are humans or very human-like, all in all.

If you think people would invent new weaponry around Cyclenergy, please tell! Just don't go too far into futuristic things. Sorry, no (malfunctionning) teleportation devices, Mr Spocky.

How Cyclenergy performs

The main plate, the Cyclenergy! Here is a bulletpoint list so you can tick cases in your heady :

  • Everything which is using fuel or electricity in our world would work with this Cyclenergy instead. Cars, computers, light...
  • On the other side, firearms, explosives and such don't need this Cyclenergy to work as expected. Their electronic parts like aiming lasers... uh... would need it much more.
  • You can include or not short-timed fuel devices into the Cyclenergy system, such as AA or anti-tank missiles and flamethrowers. Just not on long-duration devices (intercontinental missiles : Cyclenergy only!).
  • The tools to produce the Cyclenergy are as light, as easy to use and as expensive as our batteries. These tools would also give the same power (or somewhat more) as them, while requiring little fuel-like resources as an upkeep.
  • The Cyclenergy would vanish very quickly outside of their production time, even with batteries to hold them. Let's say... around 1 hour till you're totally out of power? Production would come back at about the same speed.
  • Speaking of time, the time you can produce Cyclenergy would be based on a day-night cycle, from around 7 AM to 7 PM, local time (so around when the sun's out). When saying 7'o clock it's between no and full-production. Also note that, due to the local time, moving east or west can shrink/enlarge your "Cyclenergy duration".
  • Having sunlight is NOT needed for Cyclenergy production, it's anything you can imagine, but not solar panels. This means they can work underground, too! It would be terrible to attain our current tunnel and mining technology otherwise.

The problems

As far as I can picture it, we are facing a huge issue with logistics -no vehicles during nighttime- and electronic-based weapons and equipment (aimed-assist, GPS...), but also with communications. Indeedy your favourite satellites would cut out every night, and you can't communicate with either computers or phones with anything on the planet's opposite side, since well... One device will always be off. As I said, daytime, local time!

Sooo... How people would work their way out winning open wars with this kind of technology? Especially, how would that affect weaponry and direct confrontation strategies?

  • $\begingroup$ To summarize: There is no long-term energy storage in your world, period (with the exception of biological beings that can function non-problem around the clock)? $\endgroup$
    – Alexander
    Commented Nov 5, 2020 at 23:45
  • $\begingroup$ @Alexander Yes, that's the gist of it :). $\endgroup$ Commented Nov 6, 2020 at 10:15
  • $\begingroup$ VTC:Needs Details. You've asked a question that would require an entire library of books to answer. How would (all) of modern warfare, tactics, and strategy change? Everything from a knife to ICBMs? Everything from a platoon to diplomacy? Stack Exchange uses a one-specific-question/one-best-answer model because it is not a discussion forum and you basically just asked us to write your book for you. Please read through the first two bullets in our help center. $\endgroup$
    – JBH
    Commented Nov 7, 2020 at 4:17
  • $\begingroup$ @JBH Yes, after having re-read my question, I found that even though I provided a specific context with rules, there is a lot to talk about. I think I will rephrase the question to only talk about direct warfare confrontation and weaponry, and maybe create another question for communication only. $\endgroup$ Commented Nov 9, 2020 at 10:44
  • $\begingroup$ You'd get better, more useful answers. Note that "direct warfare confrontation and weaponry" is still too broad. Planes? Submarines? Nuclear artillery? Pistols? It would help tremendously if you asked about one, specific combat encounter. Describe the specific elements (people & equipment) involved. From help center, "Your questions should be reasonably scoped. If you can imagine an entire book that answers your question, you’re asking too much." $\endgroup$
    – JBH
    Commented Nov 9, 2020 at 15:07

3 Answers 3


If cheap, fusion power existed we would use that power to apply heat and pressure to hydrogen and carbon to produce oil (or electrolyze hydrogen) and use it as an energy carrier, just like a battery, for anything we could not fit a fusion reactor into (because batteries suck). If Cyclenergy is as abundant as you imply it is, we would do the same.

You would then have a class of technology powered by Cyclenergy that could run indefinitely during the day but not at night, and a class that is conventionally powered which could run whenever for only for finite periods of time before refueling or recharging.

The technology and vehicles powered by Cyclenergy might be very very powerful compared to the more conventionally powered stuff since they have a limitless source of energy, but fossil-fuel fighter jets and missiles will still dominate over your overpowered Cyclenergy technology at night when they are just paperweights.

Taking a fossil-fueled weapons platform against a Cyclenergy weapons platform would probably be like bringing a knife to a gun fight, but knives are still super effective when your opponent is unarmed (as a Cyclenergy weapon effectively would be at night).

Tactics wise, it would mean that less well-equipped factions would probably hide during the day. Depending on potency, satellite weapons also seem like they would be far more deadly while they were functioning and make ICBMs obsolete.

If your weapons are long range enough, you could also target enemies on the other side of the day/night line if they were west of you in the morning, and east of you in the evening.

  • $\begingroup$ An interesting take-on the issue; If you can't keep cyclenergy during the night, then just transform into something you can use then! Like going with crossbows when you can't use guns. However, I may miss something in your explanation, but isn't remaking oil to fuel your devices a bit far from the rule of "electricity and fuel is now cyclenergy"? Would there be another way? $\endgroup$ Commented Nov 6, 2020 at 10:31
  • 1
    $\begingroup$ @Tortliena Yes, but that rule also implies a lot of weird stuff that would break the world. How do you plan on explaining that you cannot burn stuff or have endothermic and exothermic chemical reactions? Because burning fuel is not very different from the biological processes that keep you alive. How come I can use gunpowder, explosives, and flamethrowers but not fossil fuel? It is inconsistent enough to completely break my suspension of disbelief. $\endgroup$
    – DKNguyen
    Commented Nov 6, 2020 at 14:26
  • $\begingroup$ Humans go to great lengths to produce artificial light so they can work in the dark. In your case it is much more than just light; It is all machines and tactical advantage. But your rule implies that everything suddenly goes dark after 7pm. But if that was not your intent then it means they must have another way to convert and store it, and if they do then why isn't it being used everywhere? It is far, far too big a limitation of Cyclenergy to just have people ignore and not have people put an insane amount of effort into figuring out a way around it. $\endgroup$
    – DKNguyen
    Commented Nov 6, 2020 at 14:27
  • $\begingroup$ Oh, yes, I see your point now. It would be better for me to say that the world miss gas, oil and coal then, whether they can or cannot be made back with Cyclenergy. If they can be made, your answer is totally plausible then! And since I didn't clearly stated that they cannot, your answer is valid! $\endgroup$ Commented Nov 9, 2020 at 8:19
  • $\begingroup$ Marked your answer as my "useful one", since while it doesn't give as much alternative weapons as Ash's one, in my opinion it covers more of the general strategy that would be employed. $\endgroup$ Commented Nov 9, 2020 at 10:56

I'd be looking at weapons which involve using cylicengergy to "charge" some other energy storage system, and then releasing it is free or near zero cost. You mentioned explosives, which are valid, but I'm thinking more kinetic or gravitational potential energy.


  • Space junk in orbit that can be turned into meteorites.
  • ICBMs that can hold in LEO
  • Antimatter
  • Chemical weapons. (Charging refers to making the chemicals)

So use your abundant periodic energy to make something which can be cheaply used to great effect at any time.

  • $\begingroup$ lol oh yeah. You basically have infinite energy so just make anti-matter. I hope you don't use Cycleenergy to power the magnetic fields that keep the anti-matter safely contained through the night though... $\endgroup$
    – DKNguyen
    Commented Nov 6, 2020 at 6:49
  • $\begingroup$ @DKNguyen "we do but not my problem" says the antimatter engineer, clearing out before the nightly launch of the antimatter warhead into the enemy base. $\endgroup$
    – Ash
    Commented Nov 6, 2020 at 6:57
  • 2
    $\begingroup$ "The launch CANNOT, I repeat, CANNOT be delayed. The rocket MUST be well on its way by 7 PM. I don't care where it goes but it definitely can't stay here!" $\endgroup$
    – DKNguyen
    Commented Nov 6, 2020 at 6:58

I see little problem for traditional wars. If two nations are fighting, as soon as night comes and their lasers start failing, they will stop and each side would go back to their trenches. Stopping the fighting at night has been common for centuries. In case one of them were going to do a nightly attack, they would use e.g. knives.

Not having logistics or communications at night isn't that bad, either. A message received at 6:59 pm would have to wait til 7:00 am to be relayed. Note that although you would not be receiving information about e.g. troop movements, they are unlikely to be performed since they don't have Cycloenergy at night, either. They would have to move by foot, or perhaps use animals (useful to escape from a more powerful enemy in the middle of the night).

The main problem I foresee is that having those cycloenergy intercontinental missiles, it would be possible to launch them so they arrive at dawn. You send your long-range missiles following the sun from West-to-East (even if it's a longer journey) so that they have cycloenergy available, but hit their target at 7:00 am (local time), barely seconds/minutes after the defense systems of your enemy begin the day cycle and can start recharching after getting dry during the night.


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