[Note: This is the first in an occasional series on gleaner technology.]

In the Philippines, the cost of electricity often means poor citizens are left in the dark—even when the sun is shining.

Social entrepreneur Illac Diaz e up with an indigenous and ingenious solution for lighting problems in the country’s e areas: He use plastic bottles, water, and chlorine to lighten up the dark homes of poor. The solution provides both a cheap source of lighting and environmentally friendly jobs for hard-working entrepreneurs.