HOME > WHAT IS A CFL? Compact Fluorescent Lamps (CFLs) are an increasingly popular way for households to increase their energy efficiency. A typical CFL will last eight to ten times as long as an incandescent, but only use one-fourth the power: thus a typical household can save on electricity bills and on replacement bulbs by switching over.

A CFL bulb is similar in size to a conventional bulb, and has the same screw-in fitting at its base. But rather than a glass bulb, it consists of a "ballast" of plastic and electronic parts and a narrow, spiralling glass tube. The tube contains gas; when an electric current flows through the gas, it provides light.

Fluorescent lighting is not new - it goes back more than a century - but it has never been popular as a form of home lighting, for three reasons:

Until recently, all fluorescent lights were long glass tubes which were hard to install and required special, expensive fittings.

The tubes tended to flicker, be slow to start, and needed frequent replacing.

Fluorescent lighting used to be white, or 'cold', like daylight. Many people found it less comfortable than the yellow, or 'warmer' light from ordinary bulbs.

However, technological advances have removed these hurdles. CFLs are now small enough to fit into ordinary fixtures, they no longer flicker, and the light can be as 'warm' as any old-fashioned bulb.

There are two downsides to CFLs:

They can cost a bit more. That's why Rising Sun's CYES program offers FREE CFLs as part of its free 'green house calls'.

Because CFLs contain tiny amounts of mercury, they must not be disposed of as ordinary garbage, but should be treated the same way as batteries and disposed of at your local recycling center, where you will find a free drop-off box for CFLs. Many hardware and department stores, such as IKEA, Orchard Supply Hardware, and Home Depot, offer similar disposal boxes. They must also be cleaned up properly; see this page for more information.