The Solar Bottle Bulb : Lighting Homes the Cheap and Eco-Friendly Way

I grew up in a depressed area in my country, where houses were virtually built right next to each other. Back then, I could easily hop from the roof on my house to my neighbor's with relative ease (kung fu style), but really, I wouldn't dare to, considering most of the houses were built from light materials, and I would most likely fall through my poor neighbor's roof.! From a very young age, I realized that one of the biggest problems my parents had to deal with each month was the electric bill. I wanted to help, and the most obvious, and only idea I had back then was to try to minimize the use of electricity, especially during daytime.
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Fast forward 15 years later to 2011, we had moved out of there and into a decent neighborhood , but still, the country has the highest electricity cost in Asia, and poverty has increased substantially. Hopefully, a means to ease the problem might have just surfaced - a safe, and sustainable daytime light source, the solar bottle bulb. Using the idea of light refraction, we use the light from a hole on the roof and have it pass through clear and filtered water. This way, sunlight is dispersed through the water, bending and amplifying its waves, giving light to the entire room. It's like a skylight - only way cooler.
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Try this! Place a pencil inside a clear glass of water, observe it from the side. Does the pencil appear broken? This simple trick is due to a property of light called refraction. Refraction causes light to bend when it passes a substance of one density into another, in this case, light passed from air to glass to water. Light bends because the speed in which light travels through one substance depends on the density of that substance, light passes through air at the rate of 186, 000 miles per second, but as soon as it hits the water substance, it's speed slows down to 140, 000 miles per second, this change in speed causes the direction of the light ray to change, thereby giving us the illusion of a broken pencil.

You will need

• Empty PET soda bottle
• Galvanized Iron (GI) Sheet
• Rubber Sealant
• Bleach ( keeps the solution clear from algae & molds)
• water
• Basic Tools (metal sheet cutter, chisel, hammer, power drill)

_{Downloadable guides, and a step-by-step how-to video can be found here}

This cheap, eco-friendly lighting is slowly gaining popularity, aiming to help people in depressed areas all over the world. In the Philippines, it is widely influenced through the efforts of the MyShelter Foundation, through its "Isang Litrong Liwanag" or A Liter of Light Project, and aims to light a million homes this year, 2012 using the eco - friendly solar bottle bulb. This cool innovation is also gaining popularity in other countries like Brazil, India, and Nigeria. Most cash-strapped families in urban poor communities live in small, cramped, make-shift homes. Made out of light materials with little to no windows at all, rendering the house dark, even during daytime - forcing families to use electricity. In some cases, this has been the cause of most fires in these urban poor communities, lights left on running for almost 24 hours each day, legal or illegal connections failing, and those that cannot afford electricity are forced to use candles, or gas lamps. Using the solar bottle bulb reduces the risk of houses catching fire caused by unattended gas lamps, or failing electrical connections due to overuse. Doing so, also helps families cut down their monthly power bill by using lights only when they need to - at night.

• Safe - reduces risk of fire from faulty & illegal electrical connections.
• Sustainable
• Cheap - Just $2-3 to make one solar bottle bulb, switching off lights during daytime and using the solar bottle bulb can help families save each month on their power bill.
• Eco-friendly