Let's say you get stranded on an island with the following constraints:

  1. You have no tools or man made artifacts of any kind
  2. There is no way to contact or be found by anyone
  3. The island has every naturally occurring resource

What would be the steps needed to be able to generate a constant source of electricity?

  • $\begingroup$ I suggest reading the manga Dr Stone which goes through how to do this step by step. $\endgroup$ – John Nov 1 '20 at 14:47
  • $\begingroup$ welcome to worldbuilding, this question is great, but a tad more detail might help with getting a better answer $\endgroup$ – Topcode Nov 1 '20 at 15:39
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    $\begingroup$ I VTC'd for Needs Details but frankly, I should have voted as Too Story-Based. The question of how to create an electrical generator can be trivially looked up on Google and you don't bother telling us the end point (AC/DC? voltage? amperage? duty cycle? Impedance?). Just developing the tech to extrude wire and coat it with enamel could take more than a lifetime (see this question). $\endgroup$ – JBH Nov 1 '20 at 17:57
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    $\begingroup$ Jules Verne tackled this exact topic in The Mysterious Island (1875) in order for his characters to build a telegraph. $\endgroup$ – user535733 Nov 1 '20 at 20:23
  • $\begingroup$ EE Doc Smith did this in The Spacehounds of the IPC. Two people were able to land on a small moon with a perfect climate (yeah, I know, but this was the pulps). The guy was a brilliant engineer, and he built a hydro-electric generator and a hyperspace radio. No, I don't believe it could be done by one man, but it was a fun read. $\endgroup$ – NomadMaker Nov 2 '20 at 4:19


  • you do nothing else, food and water is ample.
  • you know what you're doing.
  • you're working 80 hours a week on this.

I'd give it about 3 years. This is less than the estimate I gave here but that was a million people who spent most of their time looking for food, and needed industrial revolution levels of power. In this case, you're a smart guy who can work full time on this and has no supply issues.

You don't need AC power, you don't need to build a dam or windmill, you need a battery, and all you need is some basic pottery, and two different metals, e.g. iron and copper, such as this artifact dating from second century Persia.

enter image description here

Copper, iron, and clay are relatively accessible to simple stone age mining. Finding and extracting and purifying this is non trivial to a novice, but if you know geology and chemistry, you could get these resources in a few years. Almost all of your time will be digging.

You'll also need to make a wine or vinegar to go in the jar and work as an electrolyte. Making really bad wine is as simple as "letting fruit go off in a container" so I'm sure you'll manage this too.

It will provide a constant low voltage DC electricity source. When the "battery" goes flat, replace the electrolyte with more bad wine.

It puts out about 1.1V, can do several days at about 100ma. 5 of these connected positive to negative could charge a modern smartphone.

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    $\begingroup$ This will work just fine. However it, does require you to set up iron smelting, which is a lot more difficult with no starting tools than one thinks. years is the right timescale for this. $\endgroup$ – user79911 Nov 1 '20 at 20:01
  • $\begingroup$ @MarvinKitfox no, the OP said "every naturally occurring resource" so that includes known native metals, you can just pick zinc and copper nuggets up off the ground on that island, no smelting required en.wikipedia.org/wiki/Native_metal $\endgroup$ – Pete Kirkham Nov 1 '20 at 23:45

Assuming you do not need to spend any effort in actual survival:

The main difficulty will be is acquiring a source of metal.

You need metal for conductors in any form of inductive electricity generation, and to convey the electricity (wires)

However, your premise states "The island has every naturally occurring resource" So there should be native copper, and magnetite rocks. And let's assume we know where to get the materials!

Given this... I could have a pathetic little hand-driven generator running in 2 days. Or in about 3 months I can have a stream dammed, with a water chute driving a basic waterwheel, turning a generator via direct drive. The axle is just a smoothed hardened treetrunk, greased by whatever. The generator is just a bunch of magnetite rocks tied to the waterwheel, passing by a very simple coil of copper wire beaten from native copper.

The output is (very) low voltage AC at whatever frequency the magnetite chunks pass by the coil. Likely about 10Hz or slower, and under 5v.

But hey, it is electricity.

Without the native copper ore, or silver, or gold .... is there another metal ore that can be in native metal form, and is ductile enough that it can be formed into wire by physical shaping without melting? Developing a metal smelting industry from the ground up is a very,very hard and timeconsuming task, requiring a detour through pottery, charcoal making, brickmaking and more.

  • $\begingroup$ You do realize that copper is not found in nature as pieces of copper wire nor even as chunks of metal, and that you'd only have about 0.6% of copper in ore, and that mostly in form of copper sulfides? So yes, you'd need to extract and smelt it. So two days - no way... Two years, maybe, if you'd been preparing for that exact event for at least a decade before, and if you'd happen to be at extremely favorable place... $\endgroup$ – Matija Nalis Nov 1 '20 at 23:27
  • $\begingroup$ @MatijaNalis it is very rare, but it does occur - see google.com/search?q=native+metal+copper+nugget&tbm=isch $\endgroup$ – Pete Kirkham Nov 1 '20 at 23:50
  • $\begingroup$ @MatijaNalis I do indeed realize that copper IS sometimes found in nature as chunks of metal. Please lookup "native copper ore". I'm editing the answer to include a link behind the name. You DID notice that the very same link you used in your comment, has the phrase "Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals)" AND AN IMAGE right at the top of.... a chunk of NATIVE COPPER!?!? $\endgroup$ – user79911 Nov 2 '20 at 7:54

I've got an idea but it would take allot of work. Firstly, create a dam with rocks and stuff if there is a nearby stream/some sort of flowing water. Then make a wheel shaped object out of wood. Now use a stick as a dowel and put that through he centre of the wheel. Use bark to create fins around it and attach that to the dam. The dowel would then go through the rocks and you would have some sort of fabric from a nearby sheep (wool) or cow (leather) to create a belt, from there all you need is a way to make that turn and rub against another piece of fabric to create static electricity, I'm not sure what you would do with this but there you go, electricity!

  • $\begingroup$ OOh, static! That would be electricity. Pathetic, feeble, utterly useless for industry. But it is electricity, and much easier to make than playing around with magnets and metals and stuff. $\endgroup$ – user79911 Nov 1 '20 at 19:56

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