Water Bottle Lights

I recently learned of a simple idea that is being used to bring light to many homes and businesses in third world countries during the daytime that would otherwise do without. Some because they have no access to electricity or others because it costs so much that they would rather not use electricity except when absolutely necessary.

This innovation is known as water bottle lights or solar bottle lights. They use no electricity. Instead they act as mini skylights or solar tubes. Empty plastic soda bottles are usually the main material used to make the lights (although in one case I saw glass bottles have been used as well). Corrugated steel and sealant are needed as well. And the final materials are simply purified water and bleach. After they are assembled they are installed in the corrugated steel roofs of the home, church, or workshop, etc. with the top part of the bottle sticking out of the roof and the bottom of the bottle extending into the ceiling below. These "light bulbs" then work by simply harnessing the power of the sun by refracting the light that comes through the water in the bottle down into the room below. They provide up to the equivalent of 50 watts of light. They can last up to four or five years.

They have their disadvantages. The idea probably would not work in countries with climates that get cold enough that the water could freeze. And of course they do not work when the sun is not showing. But the advantages outweigh those. Some of the advantages are the savings in electricity can be used to help a family buy more nutritious food or pay for books for school.

I've included three videos about the water bottle light or solar bottle light concept below. But if you want to see even more, click on this link for more solar bottle light youtube videos.

Image source: y0s1a @ stock.xchng

This video says the idea for using water or soda bottles for a light source seems to have originated in Brazil by a mechanic named Alfredo Moser who used the idea in his workshop during an energy crisis and blackout in 2002. Others say that an MIT student came up with the idea. And others say that the idea has been around for decades (maybe even longer), using glass jars or bottles. Whatever the origin is, as shown in previous videos the idea has spread to other countries, to the benefit of many.

Centuries ago deck prisms were used to bring sunlight to the decks below on sailing ships. Laid flush into the deck the prism part of the glass would refract the light to the room below. They served pretty much the same purpose as the water bottle lights being used today. Modern reproductions like these seem to be used for decorative purposes, such as paperweights, in homes. But it would be interesting to see if they could be installed in places similar to the "water bottle light bulbs" mentioned earlier. These perhaps could be used in places where water would freeze. Although of course they would be much more expensive than the water bottle method.

While not quite the same concept as the solar water bottle lights for lighting the home, as mentioned above, this is a cool concept as well that uses water, light and solar power to bring light to you, whether camping or in an emergency situation. It has the dual purpose of being a water bottle and a lantern. It might not shine quite as bright as a battery powered lantern. But the mini solar panel on it means it can be charged by sunlight so you won't have to worry about your batteries running out.

This solar lantern does not use water, so it is not dual purpose. But it does seem to give efficient light...being 3 to 5 times brighter than a kerosene lamp.