Incandescent light bulbs are generally considered inefficient when compared to other modern forms of lighting. This includes fluorescent lights and their smaller counterpart, the CFL (compact fluorescent lamp), considered a direct replacement for incandescent light bulbs. In some areas, such as the European Union, Australia, and Switzerland, incandescent light bulbs are being phased out to save energy.
The history of the incandescent light bulb dates back to the early 19th century, although the basic design was not perfected until 1880, when Thomas Edison developed a long-lasting filament. Incandescent light bulbs work by acquiring power from an electrical source and then concentrating the power in a filament enclosed in a glass case. The reason the bulbs are not considered energy efficient is because the majority of the energy they consume goes toward producing heat rather than light, which wastes energy.
For comparison purposes, a 13W CFL produces the same amount of light as a 60W incandescent light bulb. On average, CFLs use 75 percent less energy and produce 75 percent less heat than incandescent light bulbs. They also last up to 10 times as long. For this reason, CFLs reduce the long-term costs associated with lighting, although they are more expensive initially than incandescent bulbs.
When upgrading from the inefficient incandescent bulb to the energy-efficient CFL, the bulbs should be replaced one by one as they burn out, rather than simply removing them before they are used up. This is a cost-saving measure. It avoids unnecessarily throwing bulbs away while they are still useful.
The CFL is not the only energy-efficient alternative to the incandescent light bulb. Another possibility is the LED (light emitting diode) bulb. LED bulbs last up to 10 times longer than CFL bulbs and do not contain harmful chemicals such as mercury, as CFLs do. LED bulbs, however, have been far more expensive to produce than CFL bulbs.