As the energy bills continue to soar a clever solar lighting idea is diffusing across the slums of the Philippines.

A 1.5 litre plastic bottle filled with purified water and three spoons of bleach and then fitted to a hole in the roof. The sun rays are curbed by the bottle.

“Designed and developed by students from the Massachusetts Institute of Technology (MIT), the Solar Bottle Bulb is based on the principles of Appropriate Technologies – a concept that provides simple and easily replicable technologies that address basic needs in developing countries.

“The bottles function as 60-watt lights powered by 100% solar energy. Refraction is an amazing thing, if you drilled a hole in your ceiling light would drop directly through the opening in a straight line casting a shadow on the ground in the shape of the hole. By placing a bottle filled with water into the hole, the light is refracted by the water and emitted at 360 degrees like a light bulb.”

Solar Bottle Light Bulb can only be used during the day. The bottle bulb can produce as much light similar to a 50W to 60W incandescent light bulb.

Here are the things you need to create a Solar Bottle Bulb:

1. Roof sheet material preferably 1×1.

2. Purified Water

3. Chlorine

4. Rubber Sealant

5. 1.5 Litre clears Soda Bottle

The creation process:

1. Fill the clear soda bottle with purified water and adds 3 tablespoons of liquid bleach or chlorine. And tightly seal the cap. Note that purified water is needed because moss will not grow in it, unlike tap water.

2. Cut a hole in the roof sheet as big as the diameter of the bottle. Make sure that the other half of the bottle, starting from the cap, is exposed so that it could capture sunlight.

3. Make a hole in your roof, the same size as the bottle (not the roof sheet).

4. Insert the bottle with the roof sheet in the hole of your roof and seal it with a rubber sealant to prevent leaking due to rain.

It will produce light when the bottle is exposed to the sunlight. It is expected to last for 2 years before you need to replace it.