QUESTIONS How could electricity be made feasible through early medieval technology?

Could it capable of producing enough electricity to light a just a few rooms within a two-story building? Perhaps an entire building?

I expect it to work locally not spread throughout a city, and to be a rare luxury, the equivalent of a status symbol.

If this is not possible and considering it is in a realm of fantasy, could an extremely rare "magical" mineral the equivalent of a room-temperature superconductor make continuous electricity viable? Or maybe some other kind of element, only theorized by physicists of our universe to exist?

How else could this effect technology and culture in the world, considering its availability?

MY WORLD has gone through an apocalyptic era, where most advanced technology was lost, and through several major events magic was discovered. The advent of magic cataclysms brought rare, "magical," and minable minerals. Some in our universe which are only theorized by physicists to exist. Five thousand years later, the current era is the equivalent of an Early Middle Age.

I have read the materials for creating electricity in The Early Medieval period were available, yet it would not have been able to be put to any significant use.

Here are my theories based on some light reading and (mostly) my imagination. All of which I believe would be certain consequences and limits of the medieval electricity.

Electric Lighting as a Luxury Item Electric power would be at its infancy stages, unable to power large stretches of land, but perhaps several rooms in a large manor. Such a feat would be considered a luxury reserved only for the elite, being in itself a status symbol. So an electric powered light source would be in common areas or bedrooms, while candle light would still be dominantly used.

Dependency on rushing water as power source This would mean that the electric lighting in a buildings requires a river and water mill. Could this be worked around with something like a water wheel generator within a building and a complex system of piping water?

Requires rare and expensive minerals

NOTE I am hoping not to completely upend civilization with this technology or cause an insane surge in technological progress. At least for now, my world is supposed to have major limitations to any sort of progress to industrialization.

  • $\begingroup$ welcome. I recommend this related question that might help you, as The Romans did know of steam engines but mostly considered them gimmicks worldbuilding.stackexchange.com/questions/98363/… $\endgroup$ Apr 18, 2018 at 21:02
  • $\begingroup$ Is there still an understanding of scientific concepts like electricity in your world?, if so simple lighting would be very doable as a luxury item. Perhaps knowledge on how to produce an AC current has been lost, preventing it from being a world changing thing? $\endgroup$
    – Ummdustry
    Apr 18, 2018 at 21:16
  • $\begingroup$ Incorporating an understanding of electricity's scientific concept, while losing some other knowledge may be doable. I would have to look into it. Then again that does bring up the problem of the light source. Light bulbs seem out of the question, according to one of the answers. $\endgroup$
    – MrCheddar
    Apr 18, 2018 at 21:43
  • 1
    $\begingroup$ Electricity is imaginable, light bulbs aren't. $\endgroup$
    – AlexP
    Apr 18, 2018 at 22:06
  • $\begingroup$ @AlexP: Arc lamps in evacuated glass cylinders should be possible $\endgroup$
    – nzaman
    Apr 19, 2018 at 14:51

2 Answers 2


Let's get magic out of the way first

Magic allows you to do anything unless you've developed a magic system with limitations. Therefore, of course, you can always solve the problem with magic.

A light bulb depends on a LOT of technology

People new to the site (welcome, by the way!) have yet to be exposed to the fact that technology is a pyramid. We're standing at the top, and the pyramid represents the countless people, ideas, innovations, and work involved with bringing new technology to light.

A simple light bulb is a great example. Off the top of my head you need:

  • Glass-making (preferably thin, but not required).
  • Filament manufacture
  • Insulators (ceramics at the least, plastics at the most)
  • The ability to create a vacuum (inside the bulb, or it burns out very quickly), this one's a huge problem
  • The ability to create very thin wire with very thin insulation (needed for generator windings)
  • Magnets (also for the generators) of specific shapes, sizes, and power.
  • Breakers (people always forget the breakers, but they're mandatory or you burn out your generators)
  • Speed governors (unless you don't mind flickering light, burned out bulbs, and powering only a handful of bulbs per generator)
  • Voltage rectifiers (ach, now you need to know about diodes, and that means basic semiconductor physics...)

And a lot of other things (a lot of other things).

So the real question is, what do your people know?

Now, it's your story, so you can explain all this as pre-existing technology, but that still requires people with a medieval understanding of physics to comprehend a modern power plant (unlikely to the point of unbelievable). Of course, if the modern power plant were more future tech than today and fully autonomous, then it's just a matter of hooking up wire to the output... and not getting yourself killed... and synchronizing the hundreds-of-thousands of output volts with the (e.g.) 110v light bulb in your hand.

Can you see the problem? That simple light bulb represents an enormous amount of knowledge and practical experience. The Steampunk genre is dedicated to the idea of balancing future-vs-past concepts, but there's only so much you can do.

In the end, no, it's not particularly believable that a medieval society would have light bulbs. Not unless we're talking about self-contained light panels from some future tech that people happen to find and hang on a wall and don't require a power source or wires.

And if your people had the scientific knowledge to understand electricty, they'd not be a medieval society. It's very difficult to believe a culture could have electricity and not gun powder (basic chemistry, needed for electricity...).

  • $\begingroup$ I suppose I wanted to find a way to incorporate a few rediscovered technologies from before the apocalypse in my world. Rediscovered though not completely understood. Some knowledge is known and some lost. Kind of like how one can be "grandfathered" into being an electrician, and never having read a training manual (Let alone not know how to read, which I have seen for myself around where I live). Though I might just have to go the magic route for this one. $\endgroup$
    – MrCheddar
    Apr 18, 2018 at 21:49
  • $\begingroup$ Or use Clarkean Magic (any sufficiently advanced technology is indistinguishable from magic). This was done in Robert Jordan's Wheel of Time books where occasional ultra-advanced tech was found by the people of the story. The most common were self-sustaining light panels. Whether it's fantasy magic or Clarkean magic is determined by how you explain it. $\endgroup$
    – JBH
    Apr 18, 2018 at 21:52
  • $\begingroup$ Rectifiers are not needed; incandescent light bulbs work just fine of alternating current. $\endgroup$
    – AlexP
    Apr 18, 2018 at 22:05
  • $\begingroup$ @AlexP, True, but then you need voltage limiters and frequency filters and a whole mess of other things to ensure the power from multiple generators is standardized and smooth. There were reasons Edison and Tesla were fighting. Each solution (DC or AC) has pros and cons. Each has its tech dependencies. I was just poping a list of things off the top of my head to make a point, not wanting to go so deep into the gory details. $\endgroup$
    – JBH
    Apr 18, 2018 at 22:15
  • $\begingroup$ Once again, arc lamps $\endgroup$
    – nzaman
    Apr 19, 2018 at 14:52

While electricity in general is well within medieval technology, any practical lighting solutions are outside of it.

First, there is a light bulb problem. "Energy-saving" LED or fluorescent bulbs are out of the question. More traditional incandescent bulbs are easier to produce, however, their lasting success relies on a trifecta of early XX-century technology:

  • Tungsten filament
  • Inert gas filling
  • Thin, durable glass bulb

Any of those 3 would be difficult to achieve on preindustrial level. You can still make a lighbulb without them, but pre-Edison bulbs were notoriously impractical and unreliable.

The second big problem is electricity generation. It is perfectly possible to build electric batteries with medieval technology. However, batteries can not produce enough electric power to run even a single Edison bulb for a practical time duration, and power consumption is even worse for pre-Edison lighbulbs. This is not a big problem if we can run dynamo - but alas it seems like dynamo is also out of reach of medieval technology. Dynamo employs coils of insulated wire. Producing large amounts of uniform copper coil was not achievable before industrial times, even non-insulated.

Of course, we can handwave the problems and say there is a genius inventor who mastered production of copper and tungsten wire, among other inventions - but then it would be difficult to keep the whole setting genuinely medieval.

  • $\begingroup$ That pre-industrial reference is the problem. No machines. Everything's being done by hand. If you had the machines, you wouldn't be medieval. $\endgroup$
    – JBH
    Apr 18, 2018 at 21:48

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