Soda Bottle Skylights

Here’s a way to brighten up enclosed spaces in an environmentally friendly way. The power of the sun is harnessed using a bottle full of water. Quite simply they’re used 2-liter soda bottles. They’ve been filled with water along with two caps worth of bleach to keep microorganisms out. The cap is then covered with a film canister to protect it from the sun. They are installed through holes in the roof, and in full sun they put out the equivalent of a 50 watt incandescent light bulb.

Our first thought is keeping the weather out but that is addressed in the video after the break. With proper weather sealing they do not leak. We might not be installing them in the house just yet, but what a great addition to that dark shed that has no electricity and seems to gobble up yard implements. Perhaps we’ll finally be able to find all of those hand trowels that have gone missing.


57 thoughts on “Soda Bottle Skylights

  1. This is a very clever idea.
    I’m totally gonna suggest it to a friend who have a shack on a field of his property in the middle of nowhere.
    There’s no electricity and he keeps chickens in there. The poor birds dwells in the shadow all day long and this could be a cheap solution to the problem.

  2. Saw this done a few times now. It’s getting popular in rural areas. Like you said, great for a shed.

    Way back in the 70’s, it was sometimes done with empty glass bottles. My grandfather used to have hundreds of them embedded in one concrete wall and clear beer bottles in the roof.

  3. I like it but there’d be no way to do that in most places in the US. You’d run afoul of some local ordinance or something. Solotube would probably break out the lawyers.

    Still very cool though. :-)

    1. They do not do that because light can only come in from the one direction. With the soda bottle, the light reflects many times within the bottle and spreads throughout the room.

  4. Yeah, building codes keep alot of cool and cheap innovations like this out of most urban areas in the US. But I think the green living movement is maybe going to change some of that.

    1. Codes? Inspectors? Really that is BS. I have been a General Contractor for many years and I want to tell you that you don’r need this inspected it is your house, duh! You can be your own GC and plumb or wire the home they can’t stop you. I swear I am not a conspiracy nut but every time someone comes up with something that would benefit the human race well then a million people come out with why not to do it, or “you will get in trouble solar-tube will sue you”? Solar tube don’t own the patent on trash conversion into a light do they? Give me a break! And PS if I invented a pill that you just drop into the gas tank and you would have gas forever well you would never hear about it, for big oil would make a few calls and I would be DEAD or DOA or swept into and deepd mine shaft somewhere.

      1. In my city the municipal code requires a homeowner to pull a permit for something as simple just replace a bad electrical outlet. Then you pay to have the city inspect your work after-wards
        . This is in Michigan. As for something a little heavier, like replacing an electrical panel or setting a subpanel, if you don’t pull a permit, the city will make you remove the work, even if it is done correctly! I checked on this since I am a lawyer who worked my way through college and law school working for a general contractor. I can literally build a house, provided someone puts in the foundation for me. I understand that some mid-western states, such as Iowa, are not this restrictive.

      2. First I understand this a 6 year old post, but was direct here in a current post to HAD. Thing is that in much of the US in any community that gives a shit, even where permitted to do their own work on their property the DIYer owner has to adhere to building codes and zoning. A general contractor would understand why that is so, but someone playing general contractor on the web may not.

    1. Oh man – Winter Ambient temperature! look it up, I believe water is warmer than air, right? its something like this “a room temperature of 70° F combined with a relative humidity of 10% feels like 64° F, but at 80% it feels like 71° F”

      I liked your suggestion about adding anti-freeze (the non-toxic variety they now sell) to them to prevent them from freezing and cracking.

      Also I thought heat would evaporate the water somewhat? But you could periodically refill them, I would like to see an alternative to plastic in that UV rays would eventually win.

      ***Read more: Winter Indoor Comfort and Relative Humidity —

    2. Wow, I just read the rest of the comments and I believe humans we are in trouble! It is like a Intelligence black hole, what if? and you will get crushed. When did we all get so Negative. Yes he is in a barn and this would let light into a barn so great idea for Barns and shed and the lot. . Also the point about how you would need a thin roof, well how about a hole towards the top of your wall preferably on the south side of your home! And the other point “the bottles would break down eventually” Right so would the house! and you after 10 to 20 years when the bottle break down just friggin replace them, gheeze.

      why do so many see danger and fault in a good idea? And when did we get so dumb about things? Let encourage not discourage, Duh!

  5. now, could i run these underground via fiberoptics?

    as for code violations, whats done on private property, is private. any questions or complaints can be addressed to the muzzle of my shotgun :-)

    1. Agreed, “… whats done on private property, is private..,” OR at least should be. However, if you ever decide to sell the property, you can run into lots of issues, because that’s when the state (or local government) becomes involved.

  6. yeah- done this many times- cheap/funky/it works…

    You can add anti-freeze (the non-toxic variety they now sell) to them to prevent them from freezing and cracking- a have a few variation in my book.

    Very cool stuff though.

  7. What about laying the bottle sideways so it collects more light? The cutout would be more complex, but maybe someone could make a nifty laser cut template for this or something!

    Actually, that’s a great idea!

  8. They used to do this to light lower decks of ships. They’d use a glass prism, though. As cool as this is, it’s not feasible from a maintenace standpoint. The theory is good, the implementation has problems with sealing, freezing, etc…

  9. This would only work in a very specific set of circumstances, which are only vaguely alluded to in the video. You’d need at least 40% of the bottle to be above the roof topside surface and as much as possible below the interior ceiling. In other words you need a thin “wriggly tin” roof somewhere near the equator.

    This smacks of the old “local woman lost 70 pounds in an afternoon using this weird old trick” folkloresque nonsense.

    1. This is being used as a real solution in shanty towns all over the globe! Not just those near the equator. First saw it about 3 years ago being used in an Indian slum area where there is no electricty

  10. Wosser and Aero, I don’t think it’s that outlandish (although obviously they’re in direct brazilian sunlight when he measures them). Light pipes are quite commonly used in the first world as well as the third, and skylights are even more common. I don’t think people realize just how bright it is outside compared to inside. This economist article:

    claims that homes and offices are typically lit only 1/10th as bright as it is outside on an overcast day, it just feels bright because our eyes rapidly adjust.
    Overall, this is an excellent low cost solution for jobs that don’t warrant or can’t afford sky lights or commercial light pipes.

  11. Plastic bottles? The sun will destroy them eventually. Maintenance would be as simple as replacing the bottle-sounds good. Problem is your roof would have many fragile entry points. Too much I’d think. Hate to have it start a leak in a major rainstorm when no ones home.

  12. I missed the part where they showed how to mount and waterproof them.

    Regardless, this is a neat hack, provided you can put them some building without any significant insulation thickness, use a non-freezing solution inside the bottles, and can go up on the roof to maintain the caulking.

    I’d use foil or something since there’s probably a shortage of film canisters in the US nowadays.

  13. Two related issues.

    Plastic photo-decays. Eventually, those bottles will become brittle and break.

    Secondly? Bleach also decays over time. Sunlight speeds up the process. It breaks down, more or less, into oxygen and salt and water.

  14. The guy with the workshop had 4 bottles together just to get enough light to work with.
    The places that need these bottles can’t afford electricity, and by the looks of things can’t afford very strong roofs.
    A few bottles is one thing but the number of bottles to light a big workshop like that properly i think its going to put a lot of stress on that roof it wasn’t designed for.

  15. crazy. why not just slit the bottles open and duct tape plastic skylights all over your ghetto ass corrugated steeling? lol. that came off as a bit harsh. my original intended comment was going to ask about chlorine being destroyed by sunlight. of course, the Cl is not ‘destroyed’.. and if perfectly sealed, couldn’t escape.. but.. not a factor? seriously though, that seems like a lot of work for a little light. I just think that way, you’re bound to have breakage, whether it be weathering plastic, gravity, broken face, etc.. i guess kids don’t have bb guns or slingshots wherever that is. even a paintball gun could blow a hole in that. i have even broken my car mirror with airsoft. not very soft, now, is it?

  16. Is so funny watch people around here search for problems… the bottle can break, the water can freeze, bottles can escape and break some head´s kids… bla bla bla.
    The real problem was solved. This is my point of view.

  17. nice hack, very nice. lots of possibilities for other modifications. its a very good start point.
    whats with all the concern about rules and regs?
    what about some of the billion volt stuff we’ve seen on HAD?


    i really like the fibre-optic idea for reaching various rooms. you could make your own cheap versions using tubes filled with water. not sure what tubing material/dimension would be best though.

  18. Don’t think the bleach is strictly needed since they use the same bottles laid out with water to purify it in africa, because the UV of sunlight kills bacteria so just leave them out a few hours and your water is OK they found.

    I agree on this needing instructions how to waterproof the seams though (in a dirtcheap way since this is a low-budget thing), and that they would need replacing every year or two.

    As for using fiberoptics, they’ve been doing that for decades already so that’s not new.

  19. This idea is brilliant! Now, how about filling them with sunlight rechargeable luminous fluid (glow in the dark like glowstick type stuff) instead of water so they add some light in the shed after dark?

  20. Bottles lay around on the ground for years, you pick them up and generally can’t tell that they have been unless severely messed with.

    Install them in a roof and now they will instantly decay and kill someone.

    I am laughing out loud.

  21. i saw this video and article containing it about 2 years ago, linked from slashdot.

    i wonder if the same thing could be applied to making better LED bulbs. basically, put the electrical bits in a waterproof housing then attach a bulb full of water to refract the light.

  22. IT said that it ‘automatically turns off at midnight’ how does it produce light after the sun has set?! Was that a translation problem? Very elegant solution for 3rd world (Where running 2 lights was more than the lady’s weekly pay)

  23. I meant to comment on this when it was first posted but had limited internet access at the time.

    Extremely cool! When I was younger, my parents would always moan at me for using a light bulb during the day when I could just open a curtain. Maybe this is the perfect inbetween!

  24. is a very interesting interview with the “litre of light” project in the Philippines.

    Due to lack of windows electric lighting is used to provide light during daylight hours, and the money spent on lighting is effectively lost…

    Strangely enough the power companies are actively promoting using this – by reducing the size of the power bills, the customers are likely to be good customers and pay up.

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