Interior lighting from simple oil lamps made of a saucer filled with fat and a wick remained virtually unchanged for several millennia, from prehistoric primitive lamps about 15,000 years ago until 1783 when a hollow circular wick surrounded by a glass chimney was developed providing brighter light with less smoke (like the hurricane lamps we can buy today). Within the next hundred years came gas and kerosene lighting followed by the electric vacuum light bulb.
Incandescent lighting works by electricity running through a thin
filament which offers resistance to the electricity. The resistance
turns electrical energy into a glowing heat. The heat makes the
filament white hot, and the white part is light.
But the purpose of the light bulb is to light, not produce heat. The problem with incandescent light bulbs is the heating mechanism wastes a lot of electricity (more energy is used for heat than for the light), making incandescent bulbs inefficient. In the U.S., our lighting bill is more than $100 million a day much of it wasted in heat.
Fluorescent lights are the most energy saving. A fluorescent lamp is a
glass tube, filled with argon, or argon/krypton gas, and mercury.
A higher amount of energy used by a fluorescent lamp is converted
As with incandescents, there are tradeoffs with fluorescents. For example, all fluorescents contain mercury. Proper disposal of fluorescent lights and fixtures is critical to keep the mercury out of our environment.