How can plastic bottles filled with water change lives? In the Philippines, visionary Illac Diaz has come up with an idea that is as brilliant as it is simple. Using discarded plastic bottles filled up with water and a bit of bleach, he's helping light up the slums of Manila.
Here, electric light is too expensive for most people. But now they're punching a hole in the corrugated iron roof of their shacks and inserting a plastic bottle filled with water so that sunlight from above is refracted through the liquid into the room below.