September 25, 2006

Idea: Fiber Optic Streetlights

I can think of several reasons why this would never work. And there are probably more reasons I’m not thinking of. But as a concept, I like it.

What if every streetlight had a corresponding streetlight on the other side of the planet, with fiber optics connecting them to each other? Instead of using lightbulbs, sunlight shining on one streetlight would be gathered through a lens, travel through the Earth along fiber optic cable, and come out its corresponding streetlight on the other end. Like this:

Fiber Optic Streetlight

I’m sure it would be enormously expensive to set up a system like this. But imagine never having to provide electricity for a streetlight ever again. Surely it would pay for itself in the long run, right?

Of course it’s not enough to just have a corresponding streetlight on the opposite East or West hemisphere, but it would have to be on the opposite North/South hemisphere, also. Not just the “other” side of the planet, but the true “opposite” side of the planet. This would make sure that long days on one side of the planet are providing light during the long nights on the other side. But then this presents a new problem because it would require a one-to-one relationship of streetlights on opposite sides of the planet, and I’m pretty sure there’s more need for streetlights on the Northern Hemisphere than Southern Hemisphere, so that wouldn’t work out evenly.

But maybe that problem could be solved with giant “sunlight gathering centers” set up on the sunlit sides of mountains in the middle of nowhere, providing sunlight to the streetlights on the opposite side of the planet via fiber optics.

Another problem: it would be difficult to keep these things maintained, with Earthquakes and other wear and tear that would damage the fiber optic cables. And when new roads are developed, they would need new streetlights, and it’s probably tough to keep setting up fiber optic streetlights every time you build a road.

Yeah, I know. Impractical in reality. But still. I like the idea.


Instead of stretching the optic system through the earth, why not have a solar panel that stores the gathered sunlight and then at dusk, the streetlight uses the stored energy?

I have seen solar-powered traffic lights before. Yeah, I know that’s the simpler and easier idea. I just thought this was more interesting. -David

An alternative is to have every streetlight gather the light during the day. Instead of the light being sent to the dark side of the world, it’s kept in a very very very long length of fibre-optic (stored localy), such that it takes 12 hours (or whatever) from entering til exiting. When it exits, it’s nighttime.

Each streetlight would have it’s own giant length of cable… or maybe they could share.

This method reduces the maintenance issue (long distance cables).

Anyway, totally impractical again, but another idea.

Maybe to solve some of the problems of one-to-one relationships and problems with earthquakes, you could have each streetlight’s input-cable-bunch branching off to x-number of other streetlights’ outputs. So the output of each streetlight comes from a lot of different sources, scattered geographically in some way. This way if it’s cloudy over some of the locations, light could still come from other locations. Except in case of nuclear winter, which I’m pretty sure would last a while.

Also, I don’t think the wrap-up-a-bunch-of-cable-so-it-takes -light-12-hours-to-get-through-it approach would work. You’d need 8,047,399,552.61 miles of cable for one light. That’s 118,028,526,771.61 football fields. If you wrap that up and… multiply something by pi, and account for the width of the bundle of cable you’ve got something like a couple billion shitloads of volume required. You could just wrap it around the earth, but you’d have to do that 323,168.62 times per streetlight.

Exactly, squub, imagine the pretty sight of billions of trillions of fibre-optics webbing the world.

Seriously, genetically modified giant super-hamsters who dine on their own (genetically modified) nourishment-rich hair, running in a hamster wheel generating power for each streetlight is the way to go.

While you’re out genetically modifying hamster hair, you might as well get it to be fiber-optic cable.

I feel like a jerk pointing out that findus’ hamster-based system is unfeasible, because that was the point, but wouldn’t the nutrients in the hair have to be drawn from the hamster’s food supply - that is, its hair? All the energy produced by eating the hair would have be used for replenishing the hair.

another problem is that most of the earth is covered by water so you would have a lot of lonley streetlights in the middle of the ocean. Of course, if there is no need for a streetlight on one end, it could just be set up to gather the light. Then there are the cloudy days…

A better way of transporting sunlight across the globe would be to harness the incredibly efficient biological processes that nature has evolved.

If we grew trees in the sunlight-rich areas of the world we could then burn their wood in the dark areas and use the heat to generate electricity. This would be carbon-neutral, unlike the highly polluting production of optic fiber.

Uhhh, an unfortunate problem would be the weather on the other side of the planet. If it cloudy, no sun for lights up street lamp.

The hamsters genetically modified hair has properties that greatly absorb the goodness of the sun, which it biologically converts to energy it uses to run. Therefore, it requires little eating, other than it’s own hair which is nutrient rich, if not energy rich (which it doesnt need as it’s getting it from the sun).

It appears you aren’t too familiar with even the basics of fiber optics. Namely, that “repeaters” are required to boost the light as it fades out over distance. For example, transatlantic fiber cables have a 10kv DC circuit to power the boosters. (It needs to be that high due to voltage drop over the length of the circuit.)

This reminds me of the brilliant idea I had when I was about 10. It was a continuous loop VHS machine that would continually record tv shows so that you could start watching a few minutes late and then skip through the commmercials.

My family ridiculed it as the “fast-forwarding tv”. They didn’t think it would sell if you couldn’t fast-forward to tomorrow’s stock reports.

15-20 years later, enter TiVo into the world.

2nd comment: You have read Neal Stephenson’s article in Wired from a few years ago on the immense engineering challenge of building world-spanning fiber optic cables?

Probably the best thing published in Wired during the 3-4 years I read the thing.

What about solar panels and batteries? It’s the same idea, but with much less cost and it’s already done.

Joe Engineer - Voltage drop you say? Circuit? What fibers are you talking about?

Hello everyone. It´s my first time here. I want to make a post because I have already patented the fiber optic streetlight.
Yes., only patented, I dont know if it works or if is cost effcient.

Bye everyone

Dear Sir:

We are a manuturer of electronic ballast of low pressure sodium lamp in China.
It is perfect for solar power of street lighting.

Hope it is what you are looking for.

Thank you for your time and attention.
Way to contract = email
Best regards,

Patrick Ynafei Shen
General Manager
Epargne Electric Co. Ltd.

Nordisonic Holding Co Ltd
Room 3-801, Lanzhitang
Huaqiao Road
Nanjing, Jiangsu 210029

Phone: +86 25 8687 1268
Fax: +86 25 8647 1698
Mobile phone: +86 1380 517 2132

Electronic Ballast of Low Pressure Sodium Lamp

Well….The trick to fiber optics is the strand must be perfectly unobstructed by anything…Cutting and splicing would definately, over multiple splices, eventualy degrade the light source as it travels through…So out with the hamster hair idea as they would have to grow some damn long hairs…And, as the engineer that posted was saying, light needs to be boosted on long stretches because it degrades over a span…I use liquid filled lightguides for UV curing devices and they transmit something like 98% of the UV power over a 1 meter cable as where fiber optic light guides give something like 70% I believe….So it seems to me no matter how impossible your idea sounds, using a liquid guide would make it just a little bit more feasable for use, seeing as how you can just make a long hollow cable filled with saline, or whatever liquid it is they use, for much less than it would cost to make a fiber optic cable…For fiber optic cable glass must be melted and dripped into very long strands…Very tricky and expensive process…But, anyways, far fetched ideas are much more productive than no idea at all! Keep it up

I like this idea because it has a very community feel to it— each neighbourhood would be linked to one on the other side of the world… and if a light wasn’t working, one could assume that something happened to the corresponding light, and maybe someone would be concerned enough to check in with that neighbourhood to see if a natural disaster (or somesuch event) had occurred over there.

Hello every0ne, I am teaching a course “optical communications” and my students know the following factors related this idea (hint, this idea with some difference is proposed in The things are important for understanding this topic
1. fiber optics cabel is already installed around the world, transoceanic, transcontinental, etc
2. This installed fiber used for the transmission of information but the utilized bandwidth is very small, that i suggest the utilization of the same optical communication system for the propagation of light
3. The speed of light propagation is less than the speed of light by a small amount (200 000 km/s approximately), which means that light can travel from north to south pointa on the eath very quickly
4. From communication theory, we know that the distributed approach is preferd
to make the system efficient and less cost
Due to the above-mentioned ideas (I have extra ideas) this system may be real in implementation and very important in saving invironment, less dependent on oil and electricity.
Finaly I hope to find interested professionals in universities and companies to develop this idea togother
thank you all

I stumbled across this quite accidently after googling (googleing?) “streetlights” and couldn’t help but feel a slight smile on my face as curiosity got the better of me and I read these pages. I like that everyone knows that it isn’t possible, yet you are having a very intelligible conversation weighing up the pros and cons of ideas, and essentially problem solving. As an English student my knowledge is far inferior to yours, but what if towns and cities that are “twinned” with others on opposite sides of the world provide the sun energy to power them. “Twinning mostly seems irrelevant, lets create an actual importance to this link?