I'm watching the first two seasons of Voyager and various episodes have commentary on having energy limitations -- but we constantly see crew using extremely complicated holodeck simulations. Why would they allow use of the holodeck if they need to conserve energy?

  • they need morale
    – user126198
    Commented Apr 2, 2020 at 21:58

5 Answers 5


The holodecks on Voyager run on an independent power source.

This can be seen in the season five episode Night, when main power is suppressed yet the holodeck continues to run. For whatever reason, this power source doesn't appear to require any significant amount of fuel:

SEVEN: Independent subsystems are operational. Environmental controls, holodecks. Reroute power from this holodeck to the emergency relays.

PARIS: Yes, ma'am. No luck. The hologrid is frozen.

In the episode Parallax, there was even a time when Janeway suggests trying to use the holodeck to provide additional power, which Kim shoots down as not possible due to a system incompatibility;

JANEWAY: What about alternative energy sources? Ensign Kim, have you had any luck getting power from the holodeck reactors?

KIM: Not yet. We tried hooking them to the power grid and we ended up blowing out half the relays. The holodeck's energy matrix, it just isn't compatible with the other power systems.

This is in opposition to the holodecks on Enterprise D, which were shut down when the ship was low on power (TNG:Booby Trap).

  • 6
    I've accepted this answer but I'm still a little confused. Wouldn't the reactors need some sort of... supply or fuel? I would assume that the reactors would still need to generate the power from something since they had to go find that something in the early episodes. Wouldn't a shortage of that something mean you shouldn't start consuming all of it on alternative systems, independent or not?
    – MrHen
    Commented Apr 27, 2014 at 23:34
  • 7
    Duh, once it's bootstrapped from ship's power it's run off holographic power from simulated plasma. Obviously that power isn't going to work well outside the holodeck. ;)
    – user11521
    Commented Apr 28, 2014 at 3:59
  • 4
    @Michael: They could at least make holographic bonfires, leave the holodeck doors open and reroute the energy from the life support heating systems ;)
    – PlasmaHH
    Commented Apr 28, 2014 at 10:38
  • 4
    @Kromey: I am sure there is non-holographic air in the holodecks that gets heat up by the holographic fire which then can travel through the door ;)
    – PlasmaHH
    Commented Apr 30, 2014 at 8:28
  • 3
    @PlasmaHH That is assuming that holodeck fire is hot.
    – Xantec
    Commented Oct 21, 2014 at 20:19

There actually is a very practical reason for the holodecks to have an independent power source, The EMH. It's true that the Doctor was originally an emergency program, but one would have to assume that if you have an EMH program, it's expected to run primarily when there is a major emergency. Such emergencies require more space than just the infirmary. In DS9 and TNG there are times when the doctors have to house patients in areas outside of the infirmary. If your regular doctor is incapacitated in such a situation, that would mean patients need to be kept where the EMH can go. That means holodecks have to have a power source separate from the rest of the ship. That way, even when power is at a minimum the doctor can treat patients in holographic settings.

There is another factor that we should consider. Though the culture in Star Trek originates from ours, it's not wholly the same. The mental health of the crew is going to be just as important as the physical health of the crew. Holodecks are not just a place to play silly games, and romp around before sex. The doctor orders Janeway to the holodecks when she's overworked, they have social events there, and there is a theme program every couple of seasons. I think this shows they are also thought to be a place ensure mental health. And, when you look at how they are usually used, it kind of makes sense. Though people use them for personal use as well, they are most often used for group activities, social gatherings, and it isn't uncommon for a program to run all day with a dozen or more crew members enjoying it at one time.

I suspect that compared to the running of the whole ship, the power needed to run one holodeck is pretty nominal, and group use of them is a way of being conservative in it's power use, along with solidifying relationships. Given how much they hate Neelix's cooking, allowing liberal use of the holodecks could be the only practical way of improving morale. In many ways, the holodeck programs are like Ten Forward.

  • I suspect that compared to the running of the whole ship, the power needed to run one hollodeck is pretty nominal - Yup. The ship's nacelles surely use enough power that a bit of holographic work is negligible. It'd be like turning the radio down a little in a car to get better millage.
    – forest
    Commented May 7, 2019 at 6:25

I think its because the energy that is used to produce a hologram is converted back into the same energy when the program ends. So although a holodeck uses a lot of energy while in use, its just borrowing it, not using it up. They say in Star Trek that transporter and holodeck technology is on the same principal (Energy matter convection. Or E=Mc2). I think that means these technology are about reorganising energy, not using it. Though some kinetic energy must get used in order for a hologram to interact with a human.

  • 3
    This kind of violates the laws of thermodynamics.
    – Molag Bal
    Commented Apr 9, 2016 at 7:44
  • 2
    "Though some kinetic energy must get used in order for a hologram to interact with a human." And for humans to be able to see the holograms. So, basically everything that a hologram is is non-recycleable. Commented Nov 6, 2016 at 2:42
  • This is not necessarily a bad answer, If you light your house at night there's nothing wrong with having a solar panel in the same room, the holodeck could just be impressively efficient (even only 40% waste with 60% recycled would seriously cut the energy bill), that could be a real world reason why they cant transfer power from it to other systems. +1
    – Matt
    Commented Jul 8, 2017 at 21:24

The replicators run off the EPS (Electro-Plasma System) conduits which get power from a manifold linked to the Power Transfer Conduits that carry warp-plasma from the Warp Core to the drive nacelles. Apparently they had to choose between using power for the Warp Drive or luxuries like the replicators. As other folks have mentioned, the Voyager Holodeck systems apparently run on a separate system (possibly a fusion reactor?) that doesn't easily connect to the EPS conduits. Voyager needs both antimatter and dilithium crystals to run the Warp Core, and the search for both were central to several episodes (searching for Dilithium crystals in S1E4 "The Phage", and searching for a replacement for antimatter particles in S1E5 "The Cloud").

  • 2
    Although the information you've listed is broadly accurate, it doesn't really explain where the holodecks get their power from.
    – Valorum
    Commented Apr 9, 2016 at 8:54

Because if the crew doesn't, they would go out of their minds, being stuck thousands of light years away from home.

  • Just like the death star
    – user16696
    Commented Jan 9, 2015 at 4:10
  • Other ships have managed it.
    – Valorum
    Commented Apr 9, 2016 at 8:55
  • 1
    @Valorum: For example? Commented Nov 6, 2016 at 2:43

Not the answer you're looking for? Browse other questions tagged or ask your own question.