A mechanic in Brazil has invented a way to light his house during the day without electricity. He uses plastic bottles filled with water and a splash of bleach to illuminate dark rooms.
The idea is now spreading across the world.
The lighting system works by using refraction of sunlight. It will be used in more than a million homes by the end of 2013.
Alfredo Moser is the inventor. He fills normal plastic bottles, that are usually thrown away, with two capfuls of bleach added to water. This stops the water from turning green with algae when exposed to sunlight.
Mr. Moser then drills a hole in a roof tile and then pushes the filled bottle in from below. He keeps the bottle in place with polyester resin, which waterproofs the 'window' in his roof.
He says the light is equivalent of a 40 or 60 watt light bulb. It all depends on the strength of the sunlight on any given day.
Mr. Moser says he came up with the 'Moser Light' during one of the frequent blackouts in Brazil in 2002.
“It's a divine light,” Mr. Moser says. “God gave the sun to everyone, and light is for everyone. Whoever wants it saves money. You can't get an electric shock from it, and it doesn't cost a penny.”
Mr. Moser has earned a few dollars from installing his lights in his local supermarket and a few neighbors' homes, but his invention has not made him wealthy.