A Solar Bottle Bulb is a clear water or soda bottle filled with tap water and a little bleach. This bottle in embedded into the roofs of houses, with part of the bottle outside, and part of it inside. There is sealant around the hole to keep the roof weather proof. When the sun hits the outside part of the bottle, a lot of light reaches the inside part of the bottle. The water inside the bottle makes the light omnidirectional, mimiking an electric light bulb. The bleach keeps the water clear for years. Without the bleach, the water would quickly turn green with algae. Without the water, there would be a bright spot on the floor, surrounded by relative darkness.