Even a compact fluorescent light bulb that burns out prematurely uses less
electricity while you use it -- but you may or may not break even. The environmental
advantage of a compact fluorescent bulb also depends on its lifetime, because
incandescent light bulbs require fewer resources and electricity to manufacture.
We found loads of statistics estimating the environmental savings of switching
to compact fluorescent light bulbs, but again -- it depends on your situation
and your care in selecting and using the bulbs. Here are some things experts
say to consider:
- Bulb lifetimes are only an average, and only under
ideal conditions. There's been a lot of complaints that compact fluorescent
light bulbs don't last nearly as long as they're supposed to. Indeed, the
majority of comments we read were from people who expected them to last
longer. Light bulb hour ratings are an average. So if a bulb's rating is
10,000 hours, that means that in lab tests half of the bulbs lasted longer
than 10,000 hours, while half didn't last that long. Still, with incandescent
bulbs rated for about 1,000 hours, even CFL bulbs that last only half as
long as they're supposed to result in a savings, particularly now that
CFL bulbs have come down so much in price.
- CFLs can save you money. You'll probably
save some money by switching to good compact fluorescent light bulbs,
as long as you use them in the right fixtures, keep them on for at least
15 minutes at a time and exchange any defective bulbs without paying return
shipping. So it's reasonable to switch from incandescent light bulbs
now, before their mandated phaseout in 2012. For use with dimmer switches,
new energy-saving halogen light fixtures are a better bet, though dimmable
CFL bulbs are now available.
- LED light bulbs could be the future. Experts
agree that LED light bulbs will be superior to compact fluorescent
light bulbs in many ways -- eventually. For now, they're worth considering
for certain purposes, but they are too expensive and dim for most settings.
- Pay attention to color temperature. Except for halogen light bulbs, whose
light is usually white, each type of light bulb is available in various
color temperatures, usually specified in degrees Kelvin (K). Most
light bulbs range from a warm 2,700K through various steps of cooler, bluer,
to a very bluish-white 5,000K, often called full spectrum.
- Look for lumens,
not wattage. Because the amount of light produced per watt by the different
light bulb technologies now available, new packaging regulations that
will soon go into effect will require bulbs to carry their lumen rating,
which is a measure of light output.
- Consider the warranty. Light bulb warranties
are usually specified in hours or years, but retailers and manufacturers
vary a great deal in how they handle warranty claims. As many owner-written
reviews testify, a light bulb warranty doesn't help much if the company
requires you to pay shipping to return defective bulbs. Retailers may
or may not accept returns. Also, many light bulbs are designed for specific
kinds of light fixtures, and using them with a dimmer switch, with an
enclosed or recessed fixture or in a damp setting -- even with the same
medium-base screw-in socket -- may void the warranty.
- Starting time isn't the same as run-up time. Compact
fluorescent light bulbs must start within one second to earn Energy
Star certification, but may still take up to 30 seconds or so to attain
full brightness. LED, halogen and incandescent light bulbs start so fast
that the delay is imperceptible. While you are first getting used to compact
fluorescent light bulbs, the delays can be disconcerting. Reviews
warn that in a few situations the delays can be dangerous -- for example,
if you depend on instant light for safety on stairs.
- Most dimmer switches
are designed for use with incandescent light bulbs. Reviews warn that even
when labeled "usable with dimmers," it's
possible that a compact fluorescent light bulb won't work with your dimmer
switch. The same is true of three-way light fixtures: A three-way compact
fluorescent light bulb may or may not work. Your best bet is to replace
incandescent light bulbs first in ordinary light fixtures that get plenty
of airflow and that stay on for hours at a time. Both heat and cycling
on and off often can drastically shorten the lifetime of compact fluorescent
Light bulbs and other health concerns
Full-spectrum lighting isn't the only health concern that various experts
have raised about light bulbs. Other concerns include electromagnetic fields
(EMFs) and the possible release of toxic chemicals, including mercury, if
a compact fluorescent light bulb is broken. We found some studies of both
risks. UV light is of less concern, because reviews say that light bulbs
emit relatively little UV light compared with sunshine.
Although there's evidence that exposure to electromagnetic fields is hazardous
for children -- with a connection to leukemia rates -- it's not clear whether
or not EMFs pose a problem for adults. Apparently some people are more sensitive
to such fields than others; if you've ever gotten a headache from one or
more light fixtures or bulbs, you're apt to be one of them. Incandescent
light bulbs don't emit a high electromagnetic field, but some compact fluorescent
light bulbs do -- certainly the ones that use an iron-core electromagnetic
ballast. If EMFs are a concern, select a bulb with a solid-state electronic
In addition to mercury, fluorescent light bulbs contain other toxic materials.
Most contain cadmium, lead, hexavalent chromium and polybrominated biphenyls.
Hence, reviews say it's a good idea to familiarize yourself with the safest
cleanup procedure when buying compact fluorescents (or any fluorescent light
bulb, for that matter).
Of course, disposing of unbroken defective or used fluorescent light bulbs
is a major environmental concern. A few localities have ample recycling facilities
in place, but proper disposal of hazardous light bulbs is still a real problem
in many areas. You can find links to information about how to properly dispose
of CFLs in the Useful Links section of this report.