If you are reading this, you have access to reliable, affordable electricity, but countless millions of people around the world either have no access to electricity or cannot afford to pay for enough to power even a single light bulb.
Even better, each 50-to-60 watt "light" is made from water, a little bleach, and one item you may well toss into the recycling bin on a regular basis without giving it even as much as a second thought, a plastic soda bottle.
In addition to that they can be made locally, produce no air pollution, and do not contribute to global environmental change and, in fact, keep trash, in this case plastic bottles, out of the waste stream. A total win-win situation.
Source: BBC World Service