Cheap, recyclable, and free of carbon emissions, the PET bottle lamp was invented by the Brazilian mechanic Alfredo Moser in 2001 and has been distributed by the international NGO Litro de Luz (Litre of Light) to over 1 million installations in more than 20 countries. The organization has worked in Brazil since 2014, and has already provided lighting to approximately 11,000 people throughout the country – a step forward in a land where 2.7 million people still live without electricity, according to data from the last demographic census by the Brazilian Geographical and Statistical Institute (IBGE).

Moser’s lamp has no environmental impact, which makes it a solution aligned with the United Nations’ 17 Sustainable Development Goals (SDG). The SDG are practices intended to guide national and international policies of UN member states, ranging from the eradication of poverty to gender equality to the sustainable use of natural resources. According to the NGO Building and Social Housing Foundation, each daytime PET lamp prevents the emission of 200 kilos of carbon gas per year, while a nighttime one, inspired by the Brazilian mechanic’s idea, saves the atmosphere from the emission of 350 kilos of pollution per year. In 12 months, the two can keep 209, 800 tons of carbon gas from being emitted.

Another advantage of the bottle lamps is that, in addition to substituting for electric lighting, they also take the place of kerosene lamps, which are still frequently used in places with no access to electricity and emit 270,000 tons of carbon a year, according to a study published in the scientific journal Environmental Science and Technology. Not to mention the money saved: a study released last year by the International Solid Waste Forum analyzed the installation of 336 Moser lamps in an industrial warehouse in the Brazilian state of Rio Grande do Sul and noticed a 40.8 percent reduction in energy consumption.

A man with white skin, gray hair and moustache, is wearing a short sleeve polo shirt with gradient stripes that go from white to black. He is looking at the camera and holding a white roof tile with the upper part of a transparent plastic bottle, with the cap, inserted into the middle. The bottle cap is black. In the back are tools, metal pieces in a variety of shapes and sizes, and mannequin parts standing vertically in a low-lit area.

Moser shows a bottle inserted into a roof tile: the sun’s rays shine through the water and light the space (Gabriela Romeiro/ Believe.Earth)

A Moser lamp has a low cost, since the building material consists of a 600ml PET bottle (for the equivalent of 40 watts) or a 2 litre bottle (for the equivalent of 60 watts), water and 10ml of chlorine, in addition to a few materials required to seal the cap and the space around the bottle on the roof. It has an average service life of 5 years.

The installation is also simple, but the original version can only be installed in houses without lining or insulation in the roof – a common feature of modest houses without electricity.

At the top of the image, in the center, the title "Sunshine in your home," in uppercase, and the subtitle "How to make Moser's lamp," are written in black over a bright pink banner. Below are the following 4 steps: "1. Cut out a piece of roofing tile of the same diameter as the PET bottle"; "2. Fill the PET bottle with water and 10ml of chlorine. Protect the lid with insulation tape to avoid the crumbling caused by sun exposure"; "3. Fit the bottle into the hole in the roofing tile and reinforce the ends with sealant"; "4. To install, cut a hole in the roof. The hole should be the same diameter as the bottle. Place the bottle in the hole with the piece of roofing tile so that it overlaps with the roof and fits snugly. Secure the tile with sealant to avoid leaks when it rains. The bottle will capture the sun's rays, as a prism, and spread them through the room during the day." On the lower right corner are the following credits: Sources: Alfredo Moser and Litro de Luz NGO; Artwork: Marina Lang.

The lamp invented by Moser only works during the day, since it reflects and diffuses sunlight into the interior space. The Litro de Luz organization, however, found a way to get around this limitation. “The only possible way was to store solar energy to use at night,” says Rodrigo Silveira, the NGO’s director of technology. “This was done by developing a system composed of four parts: a solar panel, to capture energy from the sun; a battery, to store the energy; a set of LED lamps inside a PET bottle; and the control circuit that allows it to function automatically when it starts to get dark.”

Today, the two most commonly used of the organization’s lighting solutions in Brazil are street lamps for public spaces, and the standing lamp, which can be carried. Litro de Luz studies the location of the installation, guides its maintenance, and offers training on how to use the equipment. Access to the technology is restricted because, according to the organization, they must assure the quality standards in the project’s execution. But the really essential aspect is the social empowerment of the communities in which the systems are installed.

On the upper left corner, the title "At everyone's fingertips" in uppercase, and the subtitle "Innovations used by the NGO Litro de Luz for domestic and public lighting," are written in white over a photo that shows people stretching their arms over their heads. Below, a chart organizes the following information into a four part grid, beginning with the section on the upper left and ending with the section on the lower left: "Daylight lamp. Created by Alfredo Moser/Brazil. Use: light interiors during the day. Materials: PET bottle, water and bleach." Next to the text is a photo of a gray-haired man with white skin touching a bright lamp; "Camping Lamp. Developed by NGO Litro de Luz. Use: light indoors and outdoors at night. Materials: PET bottle, solar panel, battery, LED lamps and PVC pipe." Next to the text is a photo of brightly lit lamps; "Night lamp. Developed by NGO Litro de Luz. Use: light indoors during the day and at night. Materials: PET bottle, solar panel, battery and LED lamps." Next to the text is the photo of a man smiling at the camera under a lamp that is lighting his face. He has black skin and a thin beard, and is wearing a black hat; "Street light. Developed by NGO Litro de Luz. Use: light public areas at night. Materials: PET bottle, solar panel, battery, LED lamps and PVC pipes." Next to the text is a photo of a lamp attached to the outside of a house, lighting an alleyway. ON the lower right corner are the following credits: Source: NGO Litro de Luz; Artwork: Marina Lang; Photos: Release and Gabriela Romeiro/Believe.Earth.