Changing Planet

How Aluminum Cans Can Power a Village

For a thrilling week every summer, explorers arrive by the dozen at NG headquarters for the Explorers Symposium, to meet and inspire each other, to share ideas, and to plan how we can help tell their stories over the coming year.

Photo by Sybille Frütel Culhane

Today was the first day of meetings and it was full of fascinating ideas and great quotes (which you can see featured in tweets from @NatGeoExplorers).

You don’t have to be an explorer to have an influence on this crew though. One of the most mind-blowing moments was when T.H. Culhane walked into the room with a glassfull of soda lighting up a lightbulb. And this didn’t just come out of his head, he got the idea last week when he saw this video, of a kid describing how he turned an aluminum can into a battery:

T.H., being a guy focused on finding cheap, accessible sustainable energy solutions that people anywhere can build for themselves saw this and was inspired. The soda can battery itself was fairly low-powered, but he combined it with another innovation he’d heard of, the “joule thief” which nearly instantaneously takes a weak charge, builds it up and then releases the increased energy.

Using the joule thief setup, he was able to use a “dead” AA battery yielding just 1.2 volts to power a 3 volt LED light.

Combining the joule thief and the aluminum can battery, he has a plan to make electric power accessible to people in some of the most rural places on Earth. In Nepal, for example, where he’d just been helping install solar and biogas generators, they have an almost absurd surplus of aluminum cans from the huge tourist industry around Mt. Everest. Filling these cans with water that has run through wood ash and picked up potassium hydroxide and using a simple electrode such as a brillo pad or pencil lead, people can set up multiple batteries, joule thieves, and LEDs and have enough light to fill a room.

Watch T.H. explain his set up:


From a kid’s video on YouTube to a real-world solution to a major problem faced by millions around the world. That’s the kind of innovation that can happen when curious minds get together, online or in person, or both. The fact that it happened on a Monday bodes well for the rest of this week-long Explorers Symposium. Get updates all week here on Nat Geo NewsWatch and on Twitter @NatGeoExplorers.

T.H. Culhane's alternate setup, using aluminum foil and a steel-wool pad separated by paper towels in a glass of water mixed with a tablespoon of drain-cleaner.



The original photo accompanying this post showed a slightly different set up (seen at right), where Culhane had poured the soda into a glass and added aluminum foil, creating the same effect. The new photo above shows the aluminum can set up as described in the text and videos.



Andrew Howley is a longtime contributor to the National Geographic blog, with a particular focus on archaeology and paleoanthropology generally, and ancient rock art in particular. In 2018 he became Communications Director at Adventure Scientists, founded by Nat Geo Explorer Gregg Treinish. Over 11 years at the National Geographic Society, Andrew worked in various ways to share the stories of NG explorers and grantees online. He also produced the Home Page of for several years, and helped manage the Society's Facebook page during its breakout year of 2010. He studied Anthropology with a focus on Archaeology from the College of William & Mary in Virginia. He has covered expeditions with NG Explorers-in-Residence Mike Fay, Enric Sala, and Lee Berger. His personal interests include painting, running, and reading about history. You can follow him on Twitter @anderhowl and on Instagram @andrewjhowley.
  • dhrumit patel

    it’s really nice to produce the electric energy ………….

  • Aaron

    I guess I’m wondering where Mr. Culhane got all the elements for the power source, including the cans, in Nepal and these other developing nations. This is an amazing solution, but in my experience many of these objects seem pretty difficult to obtain in the third world – especially the wiring.

  • Azmie

    Wow.. Renewable energy ideas are always great.. Other than Africa, with the Solar Sisters, rural Indonesia also needs help with regards to access to energy.. fuelled (no pun intended) by the efforts of the guys at Nusantara Development Initiatives (

  • zenatta

    In caring, there’s no saying how far one would go. TH, you have taken that courageous and bold step to reach out, you will ‘create inventions’.

  • Michael Alojado

    Wow this is amazing, Hope you can E-mail me the application and more detailed on how to make this. To help my people and to fight the INTERNATIONAL MINING CORP. that invading our SMALL ISLANDS. It is a big help for them to have power in the remote area where they can use for communication to report the activities in the EXPLORATION SITE to our Government officer.
    Thank you so much for this info, it will be a great help from you guys.

  • saumya


  • Dr. Thomas Culhane

    Greetings from Washington DC! Nat Geo catering staff Moses Rivera loves the utility of this innovation when he was helping me get cans and materials to build one for demonstration and had the idea of a naming contest for the aluminum-can/joule thief light. Below is what has been contributed so far…

    Name suggestions: “Sprite Light” — Nat Geo Digital Media; “Coca-Cola Light” – Rachel Bruton; “The Can-Do Light” — T.H. Culhane; “The YES WE CAN” — President Obama; “The Aluma-Light to Illuminate” — Moses Rivera;”the SEE, Se Puede Light” – Greory McGruder; “Can O’Light”, “Light Lite”, “Diet Light” — Sarah Laskin; “The Leading Light” – T.H. Culhane, “A thousand cans of light” — George Bush Senior.

    Hope y’all will join us in finding the perfect name or names for these wonderful devices that will make talking about them roll off the tongue in a fun way that will keep people talking about them until we are able to get this simple solution to safe lighting distributed quickly around the entire world!

  • Dr. Thomas Culhane

    @Aaron — excellent question — actually the innovation was inspired by standing with Dr. Alton Byers in one of several piles of aluminum cans up to our knees in a remote area of Nepal. We were on the second Blackstone Ranch/Nat Geo Innovation Challenge looking at renewable energy in the Himalayas and at conservation issues. We found, surprisingly, that the trekkers route up to Everest Base Camp was filled with photovoltaic power, micro-hydro, wind power and solar hot water and cookers (a good thing!) but that the trekking lodges, accommodating tourism demand, is producing a mountain of beverage can waste every day. So we decided we had to find a way to make those cans into something of value rather than an environmental burden. It turns out that there are beer and soda cans everywhere — in the most remote areas on earth. We’ve found piles of them in the Okavanga Delta wildlife reserves in Botswana, in Maasai villages in Kenya and in the jungles of Borneo — people bring beverage cans with them wherever they go, and then dump them after drinking. So the can, which is the source of electricity, is found everywhere. The Sodium Hydroxide or Potassium Hydroxide can be made by anybody by running water through the ashes of a campfire. The stainless steel brillo pad can be bought once and lasts for years or decades. And that’s about it. Then you need the LED and joule thief (which you can carry in your pocket) and you are in business! Thanks for asking!

  • batuhan yazırlı

    That’s what mankind is looking for nowadays ,small step for man giant leap for mankind 🙂

  • fgfjgk

    Clearly you also need to be scattered and have both a mom and sister to help you… if you wanted to try this yourself.

  • zenatta

    I am still here, can’t seem to get over this. Dr Culhane, I see you’re here too. Saying I’m intrigued is the understatement of the year as I have always been interested in alternative energy supply. I know next to nothing in cathodes and electrodes, but I am armed with an inquisitive and teachable mind, billions of cans and a deep need for decent electricity supply. Can someone like me ever get the hang of this simple yet mind-blowing invention

  • Moses

    it was a blessing meeting Dr. Thomas Culhane I was inspired by this invention to push my ideas out and make this world a better place…I believe this invention can open new door to our imagination… possibilities like: cars running on coca cola, city streets powered by cans, imagine a world where we can save money by not paying for electricity anymore. when i saw this invention i thought of school when science was fun…. when did we stop imagining?? our imagination is the key to making this world a better place. thank you for the inspiration.

  • Kennia

    Wow! Very interesting article! Amazed by the important role the cans play in triggering energy to produce electricity. This can be helpful in areas around the world that struggle with electricity, especially Natural Disaster hit areas. These are few name suggestions I could come up with … “BackUpPlan-Light”, ‘Light-A-Can”, “Illumi-Can Light”. Either way, great article and great invention! 🙂
    God Bless!

  • Dr. Thomas H. Culhane

    @Aaron: Hi Aaron — the aluminum cans are everywhere in Nepal and Africa even in the remotest villages — the beverage industry supplies coca cola and beer and sprite etc. to the far corners of the world so there are always waste cans. Pottasium hydroxide (lye) electrolyte can be made from water poured through wood ash and the only other part of the power source is a graphite (pencil lead) cathode or a stainless steel scouring pad or knife, fork or spoon (or just a bolt of stainless steel). The joule thief circuit needs a ferrite torus (which I salvage from CFL light bulbs that have been thrown in the trash and are found everywhere in the world) and a resistor (which can be salvaged off of an old circuit board) and a transistor. I’m looking through junk piles now to see which garbage the transistor can be pulled off of. The LED light bulb is found all over the world now (in the slums of Cairo you can find super bright LED flashlights for less than 50 Cents in street markets for example.) So there really aren’t any parts to this that can’t be found in the third world. The wiring is in every junk pile in old discarded computers, computer monitors and televisions — remember that the West dumps most of its electronic waste in third world countries. Hope that answers your questions!

  • […] (See T.H. Culhane’s own recent science experiment, using a can of soda to light an LED lightbu… […]

  • Acme Fixer

    I watched some Youtube vids of experimenters connecting a Joule Thief to a cement battery. This is an aluminum can with the inside sanded. The can is filled with Quick Crete from the hardware store, and a copper wire poked into it before it dries. Obviously the wire must not short against the can. They say these can put out power for months or longer. The current is low, but you just put a lot of them in parallel and/or series. And no messy chemicals.

    You do not need to use a toroid core to make a JT. A simple coil of wire with air core will do. I show how to do this in my blog, You can email me for more info on how to make a minimalist JT, and also a JT without a resistor.

  • NNar

    You are assuming your sochol is green, but you do not have any data to prove it.Before you try and control something you need to measure it, or you never know if you are making progress. You could start by evaluating the recycling program for paper. For instance, what kind of paper is recycled, and how much? What happens to it? You may be surprised to learn that after people go to all the trouble of recycling, the material gets dumped back in with all the other trash. I know, I have heard about it and seen it. Ask what day your paper gets recycled and be there when they come and collect it. See if it is collected and dumped in with regular trash.Do this only after you know it is really getting recycled.Start by looking for data, how much is recycled? Is it weighed anywhere? If not how many boxes are recycled per week? (You can always est weight from a ream of paper.) Get your teacher to ask the administration for the amount of paper purchased in a sochol year. That will be difficult to get, so so it first.Once you have an est of how much is recycled, come up with recommendations to increase that rate. I did an evaluation like this for a company, and what I found was that some of the paper that is advertised as being recyclable, wouldn’t work in the copiers, so they quite ordering it. Sometimes, it is not green to try and buy green. (like if it takes twice as much paper to make copies because it jams in the machine.)Good luck, just try and think outside the box.

  • Hans de Jonge

    What about a rechargeable aluminium can battery with a porous graphite (coal) cathode and the can itself as anode. The medium should be best aluminum chloride or less good potassium hydroxide. Maybe it is difficult to obtain aluminium chloride in rural areas. This battery could be recharged and uncharged more than 7000 times. Anybody could make a cheap electricity storage. 10 cans make 12 Volts.

  • kswagg somol

    yeah it’s nice and pretty

  • Oliver Uzochukwu

    I am more than casually interested in using simple technology to refuse the hitting power need in many country in west Africa.

    Send us clear procedure to produce the DC-DC home .


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