I have been meaning to write about this project for months now, just got around to it today. Back in September of 2011 I read about Isang Litrong Liwanag (A Liter of Light) project in Manila powered by pop bottles and bleached water! A bottle with water is enough to light up a small room. In the poor neighborhoods of Manila shacks have dark roofs and hardly any daylight. Many of the homes are not connected to the electric grid and in third world countries continuous power availability is not a given.
This year i.e 2012 is the year they plan to complete lighting 1 million homes using this green technology. The clear water disperses the light in all directions through refraction, which can provide a luminosity that is equivalent to a 55-watt electric light bulb, according to the MyShelter Foundation.
The idea behind the Solar Water Bulb is the brainchild of Alfredo Moser a mechanic from Sao Paulo, Brazil; who came up with it during the 2002 power shortage in Brazil to light up his workshop for working during the day! Like Plato said Necessity is indeed the mother of invention!
MIT students have been instrumental in spreading the usage of this simple and virtually free technology to the third world countries as a remedy to light up dark areas during the day without windows! They disperse light to all the corners of the room unlike skylights which are pretty much unidirectional.
How to Make Your Own Solar Bottle Bulb?
Raw materials Needed
1. 1 liter Pet Bottle
2. Galvanized iron corrugated or flat roofing sheet size 9″ x 10″
3. Chlorine (10ml per liter)
4. Steel Brush or Sand Paper
5. Snipping tools to cut the sheet
6. Pliers to fold the sheet back
7. Rubber Sealant or Epoxy resin – to seal and attach the bottle
8. Screws to attach it to the roof securely
9. Filtered water
On the galvanized roof sheet piece cut a circle 2mm smaller than the diameter of the bottle. Make small cuts perpendicularly along the edge and fold them upwards. Take the bottle and rub the sides to make it rough enough for the glue to adhere. Pass the bottle through the hole and hold in place using the folded edges of the sheet (1/3rd of the bottle above the fold). Apply glue to the bottle and the folded edges to seal and attach them together. Now pour 10ml of Chlorine into the bottle and top it up with filtered water. Close the lid tightly.
Now cut a hole on the roof of the shack where the light is needed. Apply sealant or epoxy resin around the opening to cover an area equivalent to the 10″x9″ sheet. Press it down and secure with screws. The bottle top which will be exposed to the elements needs to be protected (use plastic tubing and sealant to protect it). The Solar Water Bulb is ready and spreading light. The bottle light is believed to have a life of up to 5 years!!
How Does it work?
Simple: water diffracts the light, letting it spread throughout the house instead of focusing on one point. The chlorine keeps the water clear and microbe-free.
Positive Attributes – One can make on ones own Solar Bottle Bulb from waste materials! It can be installed any place world over where there is a roof. It is easily portable and yes, there are a huge number of households world over which do not get enough light during the day.
For e.g 360 million people in India lack access to electricity!!
Negative Attributes – Does not work during night when people do need light. The bottles sticking out of the roof is not very aesthetically pleasing
I am amazed at the possibilities such a simple idea provides – It is Green, Eco friendly, Cost effective and Practical! Try it out!
Things to watch out for or remember-
Make sure you seal the roof properly to avoid water damage.
Cover the bottle cap to make sure it does not disintegrate.
It only works during the day when there is sunlight.