Filipino inventor and former Norwegian minister exhibits light in a bottle

On February 7 to 17 inventors and innovators from all over the world will be gathering in Norway at the International Student Festival in Trondheim (ISFiT). ISFiT has different social and political topics with international relevance and it is also the worlds largest international student festival. One of the young inventors is Filipino Illac Diaz. Using plastic bottles and water he has found a simple solution to create light without electricity.

An invention like this is of high use in his home country the Philippines where three million people live without electricity. The water bottle lamp is currently lighting up 350.000 houses. The trick is to employ the reflective properties of water.

“It’s really simple. A hole is cut in a piece of sheet metal. A bottle is then securely fastened halfway through the hole, filled with water and a dash of bleach to avoid algae, and mounted on the roof of a home. When the sun hits the top half of the bottle, refraction leads it down to the lower half and lights up the room underneath,” said Diaz.

In many places houses are built so closely together that there is no use for windows. Cutting a hole in the roof to have light also allows the heat inside, but Diaz’ bottle light brings the sunlight in without heating up the room below.

“This solves lighting issues for those without electricity and reduces the electricity bill for those who have it,” said Diaz.

At ISFiT, Diaz will present his project in a session together with Erik Solheim from the Organisation for Economic Co-operation and Development and former Norwegian Minister of both International Development and Environment, and Paal Frisvold from the Norwegian environmental organization Bellona. The event is to take place on February 11 at 6 pm in Storsalen, Samfundet i Trondheim.

Diaz and his volunteers approach new villages by first lighting up a community house or church in order to showcase the invention to the inhabitants. A local entrepreneur is then taught how to make the bottle lights. That way, the initiative becomes a self-sustained local business.

The first 100-200 lights are given away for free. After that, the local entrepreneur sells his for $2 per unit to the villagers. This is easily compensated by the savings on their electricity bill.

Original article and video with the invention here.

More about the “Liter of Light” project and instructions on how to build a bottle light can be found at


Leave a Reply

Your email address will not be published. Required fields are marked *