Confused with the title? What you seen is right. It is a water heater that works with an electric light bulb. Hey, don't sink into thoughts searching for the possibility. Once again, this design is made by a student! Yes, a student (graduate) from Ecole Nationale superieure d' Art et de Design de Saint-Etienne named Estille Sauvage has brought us this fascinating eco friendly design. We all know the power consumption levels of existing water heaters and geysers. We can use this one some times, though it heats little amount of water at a time. Read the rest of the topic to know how it works.
I hope you are aware that electric bulb heats vigorously when switched on. Based on this principle, this Bulb water heater works. Bulb will be heated in such a way that it can explode into pieces when water is sprinkled on it. So if that heat is utilized to heat water for simple purposes like cooking, washing and some thing else, we can save energy and resources.
From the picture you can see that the electric bulb is placed on a wooden arrangement mounted by a kettle or a glass dish. The bulb and water is separated by recess of glass jug to ensure safety. This heater can heat water up to 90 degrees centigrade. You too can invent ways to save energy:)