Solar Bottle Bulbs

Using solar bottle bulbs is an innovative way to light up homes in parts of the world where there is no electricity. Bleach Water The water light bulb is simple and cheap. A 2-litre bottle is filled with clean water, plus about 10 millilitres of bleach in order to inhibit algae growth over time. The advantage to using solar water bulbs over simply cutting holes in the roof is that sunlight shining down a hole works like a spotlight, lighting only a small area within the room. Putting a water-filled bottle in the hole collects more light because light back and forth as it travels through rays travelling through denser-than- air material such as water change direction. Light reflected this way will bounce the water bottle, and will spread out to light the room more evenly. THE GLOBE AND MAIL » SOURCE: PHYSICSCENTRAL.COM