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Liter of Light

Filipino entrepreneur and activist Illac Diaz created Liter of Light to provide informal settlements with a cheap daytime lighting source that can be produced and distributed locally.

Worldwide, hundreds of millions of people live in informal settlements lacking adequate light. Residents often resort to kerosene, candles, or inventive wiring for light, risking health and safety in the process. “Liter of light” is a clear plastic soda bottle filled with water and bleach, installed in the roof as a skylight. The water refracts sunlight as it streams through the bottle, dispersing the rays 360º and illuminating the entire room. 

Recipients of the solar bottle bulbs, who pay about $1 for the bulb and installation, save money on electricity and upgrade to hand-built solar lighting systems that reduce the use of kerosene, candles, and other fuels responsible for indoor air pollution and fire hazards. Each of the hand-built solar lights reduces carbon emissions by 1,000 kg over five years. The organization provides initial supplies and volunteers to generate interest, but its focus is on teaching communities how to locally manufacture parts and install the lights, with the end goal of creating green micro-businesses and empowering grassroots entrepreneurs at every step. 

Liter of Light has spread beyond Southeast Asia to 32 countries in South America, the Middle East, and Africa to produce easily repairable solar battery kits for reading lanterns, mobile chargers, and streetlights. There are small adaptations to the design along the way; for example, in Nepal, they put antifreeze into the liquid solution, so it doesn’t expand and contract. 

During the COVID pandemic, Liter of Light launched the “Light It Forward” campaign, asking people to build a light, post it on social media, and challenge friends to do the same. Once an abundance of lights was built, they were turned into artwork, taking over parks, rooftops, streets, and public areas all over the world. The organization shared images on social media platforms to reach the decision-makers tasked with making meaningful progress on the UN Sustainable Development Goals. The campaign attracted 30 million viewers and empowered 75,000 people in communities devastated by loss in revenues from travel and tourism. 

Before the climate change conferences in 2022-23, the organization is planning a road trip through the Middle East, North Africa, and Europe to invite people to build lights for large-scale solar messages commemorating the 10th anniversary of the super-typhoon Haiyan.