CFLs Explained

A compact fluorescent lamp (CFL), also known as a compact fluorescent light or energy saving light (or less commonly as a compact fluorescent tube), is a type of fluorescent lamp.  Many CFLs are designed to replace an incandescent lamp and can fit into most existing light fixtures formerly used for incandescents.

Energy efficiency

Lighting electricity consumption by bulb type (Wikimedia)

The chart shows the energy usage for different types of light bulbs operating at different light outputs.  Points lower on the graph correspond to lower energy use.  For a given light output, CFLs use 20 to 33 percent of the power of equivalent incandescent lamps.

Electrical power equivalents for differing lamps

Compact Fluorescent (W)

Incandescent (W)

Minimum light output (lumens)

9–13

40

450

13–15

60

800

18–25

75

1,100

23–30

100

1,600

30–52

150

2,600