Liwanag Sa Dilim: Illac Diaz’s One Liter of Light Project

A good example of an appropriate technology would be the solar bottle bulbs of the Isang Litrong Liwanag/Liter of Light project.

Photo from

The idea came from a Brazilian mechanic named Alfredo Moser, and was brought to the Philippines in 2011 through social innovator Illac Diaz’s MyShelter Foundation. In addition to the appeal of its ingenuity and sustainability, Diaz made the idea of manufacturing these solar bulbs even more attractive by introducing it as an industry from which the average worker can generate profit, and one that can effectively address a pressing need among poor households.

These 55-watt eco-friendly bulbs are very easy to make and install. All you need is a cleaned and sanded PET bottle filled with water and a few drops of ammonia, carefully cut 26-gauge galvanized steel sheets (yero), and an ample amount of epoxy glue. The top half of the bottle sticks out of the roof to catch sunlight, and the water inside the bottle simply refracts or bends this to brighten up the room in which it has been placed. The cap is sealed shut in order to ensure that the water won’t evaporate, while the ammonia prevents the water inside from getting contaminated by algae. The putty lining that joins the bottle and the steel sheet keeps the contraption from falling apart. Of course, the bottle works only in the daytime, but it’s definitely better than nothing.

Photo from

Illac intends to bring this idea to the world, saying that he wants Filipinos to benefit and profit from this innovation, rather than simply being beneficiaries. To help the idea grow sustainably, the “local entrepreneur” model has been adopted. The solar bottles are not mass produced in large factories but are hand-made in local communities. Detainees of the Makati City Jail, for example, earn P8.00 for every solar light bulb they produce. This model also forgoes the environmental waste incurred by concentrating production in one large factory.

Solar bottles emit zero carbon and are more cost-effective and sustainable than incandescent or LED light bulbs. The substitution of incandescent bulbs to solar bottles showed a substantial decrease in accumulated Greenhouse Gas emissions over its 5-year lifetime. The materials for the bottles are also readily available in the communities, forgoing the need for manufacturing and transporting new bottles to areas of production. In addition to this, the money saved by families from using solar bottles instead of electric light bulbs can be used to attend to other needs, such as sending children to school.

This project has provided a sustainable light source for classrooms in rural areas and impoverished villages in the metro, helping mothers and children work or study more effectively inside their homes. The installation of the solar bottles would significantly decrease fire-related incidents caused by illegal electric connections in slum areas.

Isang Litrong Liwanag has brightened lives of many Filipinos and they intend to bring light to 4 more million homes in 4 different continents in the coming years.

 Find out how you can make your own solar bottle bulb:


Chang, Elliot. “1 Liter of Light Project Illuminates Thousands of Filipino Homes With Recycled Bottles.” Inhabitat., 19 Aug 2012. Web. 23 Feb 2014.

Diaz, Illac. “How to build a solar bottle bulb 3.0 (UPDATED 2013).” YouTube. YouTube, 13 Mar 2013. Web. 23 Feb 2014.

Garcia, Krista. “Q&A: Illac Diaz, Innovator.” Rappler. Rappler, 2 Oct 2013. Web. 23 Feb 2014.

Liter of Light. MyShelter Foundation, 2011. Web. 23 Feb 2014.

Zobel, Gibby. “Alfredo Moser: Bottle light inventor proud to be poor.” BBC News Magazine. BBC, 12 Aug 2013. Web. 23 Feb 2014.

Group members:

Alarilla, France

Bayta, Carla

Ilagan, Gabriel

Lim, Katrina

Samonte, Misha

Tadiar, Rina


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: