A compact fluorescent lamp CFL - 22W.

Compared to general-service incandescent lamps giving the same amount of visible light, CFLs use less power (typically one fifth) and have a longer rated life (six to ten times average). In most countries, a CFL has a higher purchase price than an incandescent lamp, but can save over five times its purchase price in electricity costs over the lamp's lifetime.[2] Like all fluorescent lamps, CFLs contain mercury, which complicates their disposal. In many countries, governments have established recycling schemes for CFLs and glass generally.

CFLs radiate a light spectrum that is different from that of incandescent lamps. Improved phosphor formulations have improved the perceived colour of the light emitted by CFLs, such that some sources rate the best "soft white" CFLs as subjectively similar in colour to standard incandescent lamps.[3]