Compact fluorescent lamp
A compact fluorescent lamp (CFL), also known as a compact fluorescent light or energy saving light (or less commonly as a compact fluorescent tube [CFT]), is a type of fluorescent lamp. Many CFLs are designed to replace an incandescent lamp and can fit into existing light fixtures formerly used for incandescents. Compared to general service incandescent lamps giving the same amount of visible light, CFLs generally use less power, have a longer rated life, but a higher purchase price. In the United States, a CFL can save over US $30 in electricity costs over the lamp’s lifetime compared to an incandescent lamp and save 2000 times its own weight in greenhouse gases. Like all fluorescent lamps, CFLs contain mercury, which complicates their disposal. CFLs radiate a different light spectrum from that of incandescent lamps.