A bottle light is a 2 liter plastic bottle that has been filled with clear water and a small amount of disinfectant to prevent the growth of any microscopic life that may still be present. Distilled water is best, but may not be available in developing countries. To better seal the bottle so that rain will not leak in, the bottle is first placed through a foot square piece of roof that matches the existing roof. The bottle is then placed through an opening in the roof of the house. Sealant is added around the bottle and around the attachment piece of roofing. On a sunny day, the light output of the bottle is equal to that of a 60-watt incandescent light bulb.