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The 2-liter plastic bottle solar light bulb is an genius way to light up a room while reducing the amount of power you consume through creative recycling. Recently, a group from Manila called Isang Litrong Liwanag (A Liter of Light) got together to build and install solar lightbulbs in a 500 house pilot program. Not only do they get better lighting, but they can spend the money they save on other, more important expenses. It’s amazing what a little sunlight can do. [via NTD]

Adam Flaherty

Adam Flaherty

I make cool stuff and write about other people making cool stuff on makezine.com. If you have something you think I should see, send me a tip.


  • http://pulse.yahoo.com/_5CUTUXRLPDOMJHAHFOY46LT3FY Joe S

    Maximum solar flux on Earth is about 1 kw/m^2, and there are about 1500 square inches per square meter.  So the rule of thumb would be .67 watts per square inch of bottle cross section facing the sun on a sunny mid-day.  

    • http://vrandy.myopenid.com/ VRAndy

      When you’re talking casually about light-bulbs “watts” sometimes means light equivalent to an old-fashioned incandescant bulb using that many watts.

      (That’s how we get “60 watt” CFL bulbs that consume about about 10 watts. )

      So when he says “about 55 watts” he means “As bright as a moderately bright lamp.”

    • http://vrandy.myopenid.com/ VRAndy

      When you’re talking casually about light-bulbs “watts” sometimes means light equivalent to an old-fashioned incandescant bulb using that many watts.

      (That’s how we get “60 watt” CFL bulbs that consume about about 10 watts. )

      So when he says “about 55 watts” he means “As bright as a moderately bright lamp.”

  • Gian Carlo M.

    great project
    this kind of lamp was invented back in 2002 from a brazilian called Alfredo Moser
    you can watch what I believe was his first interview here: http://www.youtube.com/watch?v=kqJdLYhzbTo

    • http://twitter.com/adfm Adam Flaherty

      Yep. I included a link to an earlier post that included a video of Alfredo showing off his invention.

  • http://pulse.yahoo.com/_S5BVQN65AGKYRAFS62WVQWZTFQ MadGravity

    Well hot dang that’s simple :)

  • http://twitter.com/kallanreed Kyle Reed

    Light bulb is a little misleading

    • http://twitter.com/adfm Adam Flaherty

      It is a bulb of light, is it not?

      • http://www.facebook.com/john.gomm John Gomm

        Nope, it’s a sun diffuser. it generates no light, merely passes it through. Nice idea tho’, and the headline is definitely eyecatching, but misleading given the expectations associated with the phrases “light bulb” and “solar powered”. “Water bottle skylight” is more immediately understood.

        • http://twitter.com/adfm Adam Flaherty

          Well, that’s what everyone has been calling it. I was thinking the same thing, BTW, and came to the conclusion that we need to make it an actual lightbulb. One idea I had to remedy this would be to create a little solar charged superbright LED screw cap that would put out light after the sun went down. This could easily be fabbed up from a surplus solar garden light on a MakerBot. This would be particularly useful in places like Africa where they have limited infrastructure and a need for good lighting.

  • http://twitter.com/kallanreed Kyle Reed

    Light bulb is a little misleading

  • Jordan Czajka

    This is just like glass deck prisms on old wooden ships

    • http://vrandy.myopenid.com/ VRAndy

      Aha. “Deck Prisms” thank you.   I’d been trying to remember what those were called.

  • Adam Eyring

    Great idea! If my garage roof wasn’t so thick, I’d give it a try with a few bottles to see if I can avoid the need to use electricity for shop lights. Of course, this is similar to having solar tubes.

    • http://twitter.com/adfm Adam Flaherty

      I think this is a really cool project. Recently, I installed a couple of fancy sun tubes in my living room and it completely changed the place. It went from dark and dank to bright and sunny. It’s amazing how much light comes in that room. And the light feels different. We had used standard lighting, which always felt a little weird. The natural sun coming in makes the place feel so much nicer.

  • Adam Eyring

    Great idea! If my garage roof wasn’t so thick, I’d give it a try with a few bottles to see if I can avoid the need to use electricity for shop lights. Of course, this is similar to having solar tubes.

  • http://www.facebook.com/people/Sohel-Rana/100002490100474 Sohel Rana

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  • Anonymous

    It’s a skylight, Very effective. 

    I assume the bleach is to keep anything from growing in the bottle..

  • http://www.facebook.com/sarita.newson Sarita Newson

    Ingenious! I would be interested to see the figures of how much electricity these lights help people save! Now lets find out a way of keeping them glowing when the sun goes down!!!

  • http://www.facebook.com/sarita.newson Sarita Newson

    Ingenious! I would be interested to see the figures of how much electricity these lights help people save! Now lets find out a way of keeping them glowing when the sun goes down!!!

  • http://pulse.yahoo.com/_JN5I3OUDYPAZFBR34MSM7XYKZ4 Capt.tagon

    Kind of like the deck prisms that the old sailing ships had to illuminate cabins, etc under the upper deck. Neat.

  • http://pulse.yahoo.com/_JN5I3OUDYPAZFBR34MSM7XYKZ4 Capt.tagon

    Kind of like the deck prisms that the old sailing ships had to illuminate cabins, etc under the upper deck. Neat.

  • Anonymous

    fgfffff 

  • http://www.facebook.com/YosephStalins Joseph Vincent

    I hate to burst the man’s bubble who said it wasn’t a light bulb because it was just passing the light the sun gave off, but everything passes the light the sun gave off one way or another. Dinosaurs and Prehistoric plants got their energy from sunlight which we now harness through fossil fuels. The light you see in your lightbulb is the result of the sun being alive millions of years ago. AWESOME NONETHELESS!

  • hemant khadake

    which bleach they usein it? it’s not shown pls give detail of it

  • http://twitter.com/jrendeiro jrendeiro

    Sweet Jesus, instead of adding a hole in the roof, a plastic bottle, mastic, etc. why not SUBSTITUTE a sheet of opaque fiberglass in place of the steel galvanized sheet. (lightbulb lights over my head)

  • http://www.polyamide-nylon-66-sheets-rods-tubes.com Florentina Rochenstire

    Light bulbs are at the top of our energy efficiency list. There is a big drive to encourage people to stop using the old incandescent bulbs, which waste a large percentage of electricity burned in heat, and replace them with more energy efficient bulbs. CFLs have been promoted as the solution. Compact fluorescent bulbs use less energy and last longer than the old light bulb, but they have one serious drawback. They contain mercury.

  • jagerfoods

    Great concept. How can you use this on a larger or practical scale? Living in central Minnesota with a roof that contains shingles, insulation, etc. this would probably not work.

  • Vinit

    Granted that the above idea is wonderful, it might not be a feasible idea for someone who live in apartments, in which case there’s always the good old solar lamp to replace the conventional light bulbs. I myself have been using a solar lamp of NIMH Technolinks(http://www.nimh.in/) from the past 7 months and i am quite surprised by the difference in electricity consumption. Mark my words fellas, Solar energy is the next big thing !!!

  • keamoore

    Want to learn I..it