http://www.dailymail.co.uk/...
What a bright idea! Brazilian mechanic uses plastic water bottles and bleach to create LIGHT - illuminating 1million homes. Alfredo Moser uses plastic bottle filled with water, bleach and the principle of refraction to light up dark rooms during the day
The secret of the liquid which fills normal plastic drinks bottles that are often thrown away, is two capfuls of bleach added to water, which stops it turning green with algae when exposed to sunlight.
Mr Moser drills a hole in a roof tile and then pushes the filled bottle in from below, keeping the bottle in place with polyester resin, which waterproofs the 'window' in his roof.