There is this project in the Philippines to install a new kind of solar light that is virtually free and requires no electricity or man made created energy at all. It involves only 3 things, an empty water bottle, 50% water, and 50% bleach. The bleach is to prevent germs getting into the water which allows the light to last for 5 years and light up all 4 corners of a room.
The idea is very simple and works amazingly well. A charity has been created to get these lights in as many poor neighborhoods in the Philippines as possible. The reason for this need is that the kerosene lights that are commonly used are a huge fire danger as well as the faulty electrical wiring used in many of the houses.
The bottle is placed through a hole in the roof of one of these small houses in the Philippines and sealed to the roof. The sunlight hits the bottle and reflects light into the house as well as a regular light-bulb. Of course it doesn’t work at night but these lights are needed just as much if not more in the day time and have become a very popular way to light homes in the Philippines.
These lights produce as much light as a 50 watt incandescent light bulb and never heat up. You can watch a Youtube video below that explains this cool free solar lighting technology in more detail. You can donate to light the poor neighborhoods of the Philippines here.