Friday, March 4, 2011

Solar Bottle Light

After my epic post about Puerto Galera I thought I'd make a post about this awesome project that Illac Diaz is heading.

Isang Litrong Liwanag.

Coming off from his bottle school project which was featured extensively on the news, a light bulb perhaps appeared on Illac's head. Solar bottle light, an alternative source for daylight powered by sunlight. So that means a lot of savings from your electricity bill.

The materials to create one include: (1) 1.5 or 2 liter soda PET bottle,

(2) corrugated sheets; and (3) water+chlorox+salt.

It looks like this when assembled.

Check out this house before it was installed with a solar bottle light.

And after.

Here's another sample at a sari-sari store.

Mind you the light can actually provide up to 55 watts and goes down to about 40 watts when its raining (which is still great actually). I told my Mom's driver about this project this morning since he was complaining about his electricity bill which doubled in the past month. He doesn't have a ref and just uses electricity for light, electric fan and TV. He thinks somebody tapped into his line. Anyway, he's interested in it so I thought I'd write about it so I can show him some photos tomorrow.

The group hopes to light one million homes by 2012. You can contribute either by:
(1) Sponsoring solar bottle lights at PhP150 each
(2) Volunteer in assembling and installing the solar bottle lights in the community

You can get in touch with the group by heading over to their website (it's a work in progress for now) at

*Photos were provided by the group. I unfortunately got sick just before we were going to tour the home that had it so I was unable to get my own photos.


  1. Yay! Sayang, Aileen, the demo was awesome. Yun nga lang mainit talaga sa loob. I hope they come out with an instructional video soon.

  2. @Poyt oo nga eh, I wanted to teach my Mom's driver kaso I'm getting the chlorox+salt combination mixed up. Nung nakita ko yung pics ni Jay naisip ko buti na lang I stayed out kasi hinihika na ako ng bonggang bongga nun. Mabigat rin ako buhatin! Haha.

  3. rosario orda12:05 PM

    any safety issues that we should be concerned about?chlorox is a chemical.promising ito. :)

  4. This is such an awesome idea by Illac. Thank you very much for sharing!

  5. @Rosario they've tested it and the Chlorox contest is very small (2 tablespoons I think).

    @Swexie you are welcome!

  6. I think a glass bottle would have been better instead of the plastic liter-plus bottles. I use plastic bottles for my dog's water dispenser and it slowly deforms under the heat of the sun in a few days. How much more if it was on the roof with galvanized iron surrounding it? Just a thought.

  7. @Gomi They tested it already and it will last 5 years (that's what they told us during the orientation).

  8. bakit po walang instructional vid? gusto ko gumawa ng ganito samin. :)

  9. Ang galing! First time I've heard of this. I'm glad this is now an ongoing project to be built for so many millions of homes in the Philippines. Illac Diaz is a genius!

  10. what will happen if raining? water will enter the solar bottle light? i dont think this is a good idea as this will eventually deform due to heat of the sun and if you will put holes on the plastic also this will serve as dengue mosquito nest,

    i would suggest to buy a plastic shin roofing, try to use the white one if you really wanted bright light ;)

  11. very helpful post! =)
    meron bang seminars kung paano gagawin ito, and about some methods on how to tap solar energy for electricity?

    thanks! :)

  12. Anonymous7:56 PM

    what will happen if raining? water will enter the solar bottle light? i dont think this is a good idea as this will eventually deform due to heat of the sun and if you will put holes on the plastic also this will serve as dengue mosquito nest,

    i would suggest to buy a plastic shin roofing, try to use the white one if you really wanted bright light ;)

    hindi mag deform ung plastic bottle kc hindi mag evaporate ung water sa loob.... tyka bakit mo nmn lalagyan ng butas ung bottle db... ang nkakatakot lng baka bigla mabulog sa ulo mo ung bottle sa bigat at sa tagal nya sa bubong

  13. Anonymous9:38 PM

    Ang galing! SALAMAT xa kaalaman na naishare mo sa amin! keep up the good work!

  14. Anonymous8:11 PM

    Im so impress....!...hindi pwede zonrox nlng ang gamitn kasi wla kaming chlorox xa bahay!di ba pareho lng yan?.... sana mas higitan niyo pa ang paggawa ng recycle materials para kaunti nlng ang basura? keep up the good work!!!!

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  16. Anonymous9:24 PM

    Hello mga maker nitong water light bulb in a bottle, sana i upload nyo nalang sa inyong website yong paraan ng paggawa o pagbuo nitong water light bulb, ituro nyo nalang sa public para sila na yong gagawa. Kung totoong tutulong kayo sa mga pobre, e di, i share nyo na yong paraan ng paggawa, bkit nyo pa itinatago yong paraan ng paggawa nito? cge, ituro nyo na sa publoc sa pamamagitan ng pag upload ng instruction manual ng water light bulb in a bottle. Salamat po...

  17. Anonymous5:29 AM

    Puede ba ito sa gabi? Sa mga litrato mukhang lahat ng demonstrasyon ginawa sa araw. Siempre, kung bubutasan mo ang iyong bubong papasok ang ilaw ng araw, parang "sun roof" ba.

  18. @Anonymous I'll tell them about your request to make public how to make it.

    @Anonymous nope, it only works when there is sunlight.

  19. I am just wondering what will happen in rainy season. You have done a great work.. Really interesting.. Thanks for sharing.

  20. Anonymous7:19 PM

    tuwing daylight lng po ba to gumagana?o kahit sa gabi pwede din?

  21. Anonymous8:34 PM

    pwd pa rin kahit umuulan kaso mababawasan ng 15watt ang light na nagagawa. 55watt daw pag maaraw eh. so bali 40watt na lang pag umuulan.

  22. Anonymous9:33 PM

    share nyu rin po sana how to harness sunlight as source of elecricity to provide light during day time and night time it saves money and life.

  23. @Ecommerce during rainy season it will still work, the foundation said that the light will just lessen a bit.

    @Anonymous kindly proceed to the foundation website. The light only works during the day.

  24. Anonymous11:17 AM

    What an amazing innovation!!! thanks to you mr. diaz..for finding ways on how we can save money.especially now a days. na lahat tumataas.. i also want to encourage everyone to do the same.. if we do have something in our mind that we can contribute to help our fellowmen, kindly share it to us... salamat po.

  25. sana po mag ka meron ng module para maituro ko sa comunity nmin!!!!

  26. Anonymous2:11 PM

    sana ituro na lang kung paano gawin kung paano ung talagang pg gawa kc naiinis nako sa gawa ko mali lagi hindi nako 2loy naka pasada kc un nalang lagi gnagawa k para mkatipid nman kmi sa kuryente

  27. Anonymous2:45 PM

    sana po pki bgay na po ung tamang formula sa pg gawa ng solar bottle kc d2 po sa pangasinan monthly 2mataas ung per kilowatt kya 2mataas byarin sa kuryente imbis pang bili ng gatas ng bata at pambili ng bigas gutom 2loy abot nmin. sana po sbihin nyo na kung pano gawin at san nbibili ung chlorox. kc ang testing nmin zonrox

  28. Anonymous2:31 PM

    di ba pwede ang zonrox instead of cholox?

  29. Anonymous10:03 AM


  30. Anonymous12:10 AM

    Jaime Gabriel , too much light in your house is annoying and can cause serious skin cancer specially coming from the sunlight which contains UVA/UVB and it can cause free radicals in your body and it will destroy the structure of your DNA which leads to certain cancers. If you will use bulbs it will emmit radiation as well.. If you use the plastic bottles, UVA can pass through it and penetrate your skin. So which one is better? I think its more economical to use solar panels so you can still lit the bulbs at night and totally zero cost for electricity.

    billy j.

  31. Anonymous12:43 PM

    Ok, I get it. You are helping to alleviate one inconvenience of life in the shanties. But in doing so, aren't you giving reason for informal settlers to continue living where they are, in squalor? I think society will be a lot better off if the poor are taught to aspire for living conditions that are significantly/exponentially better than what they have now. Why equip them with materials that will just make them accept their current squalid condition as "livable"?

  32. Anonymous1:28 PM

  33. hello po were making a investigatory project about this solar bottle bulb. and thank you po for sharing this :)

  34. There is a way to add new heights to your night time enjoyment of your water element with beautiful water solar lights. They can add a calm, soft glow to a pleasant evenings discussion or a sparkle of colored lights to jazz up a party or family outing.

  35. Thank you for the excellent information and photos. You have more photos of how to actually construct these solar bottle bulbs than anywhere else I've looked.

    However, you are the only one to mention using "salt" in the water and chlorine mix. Why add salt to the water? The chlorine will prevent algae from growing. Is there an unwanted reaction between salt and chlorine, or the salt and the plastic?

    Why are people instructed to use only "purified water, not tap water" when the chlorine will prevent algae from growing.

    I am looking for instructions in English and/or Spanish. I'm surpised that the group promoting this project has not posted their own instructions for us to use with volunteer groups. I've watched all the videos I can find and there's a number of ways to do this, but actual installation instructions for cutting into the roof and installing the solar bottle bulbs are few and far between.

    I found a video from an engineer in Brazil who did the same thing 3 years ago in his workshop, so the idea has been around for awhile. I'm trying to find out more from the students at MIT who refined this idea, and can't find any info. Anyone who has more info, please contact me at CatherineTodd2 at gmail dot com. Much appreciated!

    And thanks for such a great blog entry. Very happy to find so many excellent photos and story.

  36. What is good abut a light if it works only during the day? Can the energy be saved and used in the night?

  37. Anonymous1:47 PM

    Are the corrugated metal pieces required?
    I am thinking that in many African countries, the people live in dark mud huts. The roofs are made of mud, not metal. So, can the bottles be installed through the roof without the metal and still produce light?
    Thanks for guidance

  38. Very good innovation

  39. Anonymous7:52 AM

    Hi! here's the link to the Isang Litrong Liwanag video:

  40. Anonymous12:36 AM

    Rex, it does not store any energy. I think the way this works is by redirecting/dispersing sunlight into an unlit home. The use of this is because even in the afternoon, the houses are dark due to the cramped conditions.

  41. Anonymous11:16 AM

    i dont know if you guys are watching the video how to make a solar ligth. first of all the bottle is sealed with sealant and it will not fall down because it is sealed with sealant on the top of the roof where the bottle inserted and underneath the roof inside the house it will sealed again with sealant. so that if it rain the roof wont leak at all....please watch the video it is good to use than candles that cause fire and it will save more for your electric bills

  42. I don't think the salt is necessary. Just use a capful of chlorine to keep algae from forming in the bottle. Use thickest tin for the square and a very strong epoxy to keep the bottle from sliding out. More instructions are available on and from A Liter of Light.

  43. Anonymous1:41 PM

    [I think society will be a lot better off if the poor are taught to aspire for living conditions that are significantly/exponentially better than what they have now. Why equip them with materials that will just make them accept their current squalid condition as "livable"?]

    very correct!

  44. ["Why equip them with materials that will just make them accept their current squalid condition as "livable"?"]

    Or how about we stop defining their living conditions as "squalid" They live with what they need. We live with more than what we need. They (and possibly we)don't need a "home depot" mcmansion, to be happy, productive, and feel safe and comfortable.

    I think its dangerous to teach people to "aspire" to be "like us."

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