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Liter of Light

3:46

A Liter of Light @ Night

2:18

A Liter Of Light *Official Version*

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How To Make a Liter of Light

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Liter of Light | Innovation Nation

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Old plastic bottles have now been used to light up more than 850,000 homes around the world

Liter of Light is an open source design for a low-cost light tube that refracts solar light to provide daytime interior lighting for dwellings with thin roofs. Daylighting is cheaper than using indoor electric lights during the day. The device is simple: a transparent two-liter bottle is filled with water plus a little bleach to inhibit algal growth and fitted into a hole in a roof. The device functions like a deck prism: during daytime the water inside the bottle refracts sunlight, delivering about as much light as a 40–60 watt incandescent bulb to the interior. A properly installed solar bottle can last up to 5 years.
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