Planet Earth Weekly

Climate Change and Renewable Energy: Saving Our Planet for Future Generations


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Recycling Plastic Bottles: An Inexpensive and Sustainable Way to Provide Light

Light for previously unlit homes.

Light for previously unlit homes.

It’s powerful enough to light up a home. But more than that, it’s environmentally friendly, inexpensive and easy to make.”

— Literoflight.org.

By Linn Smith

April 7, 2014—“What do you get with the sun and an old plastic bottle filled with water and a little bleach? You get a 55 watt solar bulb that refracts sunlight! It’s powerful enough to light up a home. But more than that, it’s environmentally friendly, inexpensive and easy to make.”– Literoflight.org.

Environmentally Friendly Lighting

A Liter of Light is a non-profit organization started by Illac Diaz in 2011 in the Philippines, with a goal to provide affordable and sustainable inside light for people living without it. In Manila, he became aware of people living in slum shacks with no windows and no electricity–basically living in darkness inside their small dwellings. Diaz left his job to study alternative architecture and urban planning at MIT in the U.S. where he came across the bottle technology developed by Alfredo Moser in 2002. He returned to his homeland in the Philippines, where his project has grown and provided environmentally friendly, inexpensive lighting for thousands.

Liter of Light

A Liter of Light is installed on the rooftop of unlit dwellings.

Making a Recycled Plastic Bottle Light

Liter of Light recycles liter plastic bottles, the kind used for carbonated drinks or water, filling them with water and a little bleach to prevent the growth of algae. These bottles are fit into the roof of the dwellings, with half the bottle in and half out, applying a sealant around the hole in the roof to prevent leakage. What is produced is a light that fills a small dwelling due to the refraction of the sunlight, which bends the light waves when they enter the water in the bottle. The water causes the light to slow down and bend the light rays towards all sections inside the dwelling. Without the water in the bottle the light would be just a concentrated beam shining on one spot in the house–but with the added water, it becomes multi-directional, like a light bulb! It delivers about as much light inside the home as a 40-60 watt bulb, spreading the light throughout the dwelling. These lights can last up to five years!

Training Locals for Light Installation

Liter of Light provides opportunities for locals to learn plastic bottle installation, as the the organization has set up local training centers. Locals who want to become small business entrepreneurs, learn how to install the bottle lights and make a small profit. This method is kick-starting a grassroots green economy in very poor sections of the cities. Within months of starting the project, one person had installed 15,000 solar bottles in 20 cities in the Philippines. In less than a year, 200,000 bottle bulbs were installed! The goal is one million by the end of 2015.

Plastic Bottle Solar Lights

Plastic bottle nightlights make a village safe for walking at night.

Plastic Bottle Solar Nightlights

Another branch of the Liter of Light organization is installing nightlights, which are made up of a simple circuit, a battery, four LED lights, a small solar panel and, again, the recycled plastic liter bottle. The bottle houses the LED lights with a small solar panel screwed into the top. This provides 3 watts of light that will light up an area of about 15 sq. meters (161 sq. feet). The circuits switch on and off in the presence or absence of daylight. A pcv pipe, bamboo or wooden pole can turn this small apparatus into a street light. The solar nightlight can store up to 10 hours of light through the attached solar panels.

Diaz says, “If you teach enough people how to make solar lights, they can keep their communities safe.Three to five watts is all that’s needed to light an entire village. One watt times a million people who do it could be more powerful than a large-scale power plant.” Today there are Liter of Light chapters in 53 countries with 250,000 bottle lights and approximately 15,000 solar night lights installed.

Instructions for both the day and night lights can be found online.