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Lighting the Way to a Greener Environment Lighting the Way to a Greener Environment
It's on every Top Ten list of things-to-do to
save energy and help fight global climate
change: Replace incandescent light bulbs
with compact fluorescent lights (CFLs).
The benefits are compelling. CFLs use
roughly one-quarter of the electricity of an
incandescent bulb to produce the same
amount of light. This means savings for
consumers through reduced electric bills.
And by reducing the demand for electricity,
it means less global warming pollution from
coal-fired power plants.
Roughly one-third of global warming
pollution in the U.S. is caused by coal plants
generating electricity. And lighting accounts
for 20 percent of the electricity used. For
consumers whose electricity is produced
from coal, replacing a single incandescent
bulb with a CFL will keep more than half a
ton of carbon dioxide (CO
2
) out of the
atmosphere over the life of the bulb.
Those consumers whose electricity is
supplied primarily by nuclear power can
make an impact as well. Nuclear power
plants typically sell their considerable
excess base-load capacity to electrical
distributors in nearby regions which depend
otherwise on coal-fired power. Reducing
demand for electricity in such cases,
therefore, makes more emissions-free
nuclear power available to replace carbon-
intensive coal-fired power elsewhere.
Is Mercury a Problem?
CFLs do contain a very small amount of
mercuryabout 5 milligrams, enough to
cover the tip of a ballpoint pen. The mercury
is safe while the bulb is intact or in use, and
even if the CFL should break, it poses little
risk.
Far more serious are the 50 tons of mercury
emitted annually from coal-burning power
plants in the U.S. To generate the average
10,660 kilowatt hours (kWh) of electricity
used by the typical household each year, a
power plant will emit about 245 mg of
mercury (roughly 0.023 mg of mercury/kWh
of electricity produced). By using CFLs
instead of incandescent bulbs, homeowners
will reduce their electrical demand and cut
mercury emissions as well.
Assessing the Impact
Let's compare a 23-watt CFL with an
incandescent bulb that produces the same
amount of light, namely a 100-watt bulb.
Since ENERGY STAR-qualifed CFLs last
five to ten times longer than incandescent
bulbs, this example compares one 23-watt
CFL with five 100-watt incandescents,
equivalent to the minimum expected lifetime
of the one 23-watt CFL.
1 23-watt CFL
5 100-watt incandescents
Cost of bulbs (Home Depot prices)
$4.00
$3.15
Lifespan of bulbs
5,000 hours
5 x 1,000 hours
Electricity used over bulbs' lifetime
115 kWh
500 kWh
Cost of electricity (at 10�/kWh)
$11.50
$50.00
CO
2
produced
230 lb
1,000 lb
Mercury (electrical generation)
2.6 mg
11.5 mg
Mercury (in the bulb) *
5.0 mg
0
* With proper disposal, the mercury in the CFL will not enter the environment.
� 2008 by Eleanor Revelle Making the Switch
For those who haven't made the switch to
CFLs yetor who were unhappy with
fluorescent lights in the pastit's time to
check out the nearest lighting display.
CFLs now come in a variety of shapes
and sizesmini-spirals small enough to
use in table lamps, sconces and ceiling
fixtures; globes for bathroom vanity
fixtures; chandelier bulbs; recessed
downlights; and more.
CFLs can replace incandescent bulbs in
almost any fixture. Some are specifically
designed for use with dimmers or in three-
way fixtures.
The amount of light that any bulb will
put out is measured in lumens. A 100-watt
incandescent bulb will put out about 1,600
lumens. Replacing that bulb with a 23-watt
CFL will also produce 1,600 lumens, but it
will require much less power.
CFLs are available in a range of color
temperatures. For a warm (yellowish)
light, look for a CFL labeled soft white,
with a color temperature of 2,700K
(degrees Kelvin). CFLs labeled bright
white and daylight will have a cooler
(bluish) light and higher Kelvin numbers
(e.g., 3,500K or 5,500K).
Look for ENERGY STAR-qualified
bulbs. These have been tested to meet
stringent performance criteria; they use
75 percent less energy than incandescent
bulbs and last up to ten times longer.
Disposing of CFLs
Mercury is a potent neurotoxin, and proper
disposal of used CFLs is a must. The Solid
Waste Agency of Northern Cook County is
now sponsoring CFL drop-off locations in
its member communities. Residents are
asked to place their used bulbs in zip-lock-
type baggies for extra protection.
In addition, ComEd is partnering with the
Illinois EPA and Ace Hardware in a pilot
CFL recycling program. Through June 2008,
participating ACE Hardware stores in
northern Illinois are accepting used CFLs
from ComEd customers.
If a CFL should break, scoop up the glass
fragments and fine particles with stiff paper
or cardboard and put them in a plastic bag.
Do not use a vacuum or broom. Wipe the
area with a damp paper towel and place that
in the bag, too. Seal the bag, place it in a
second plastic bag, and dispose of it
properly. If weather permits, open windows
to allow the room to ventilate.
Online Resources for Additional Information
ENERGY STAR comprehensive CFL webpage: www.energystar.gov/index.cfm?c=cfls.pr_cfls
Environmental Defense detailed guide to finding energy-saving light bulbs that work for you:
www.edf.org/page.cfm?tagid=632
Solid Waste Agency of Northern Cook County list of CFL drop-off locations, hours of operation
and other pertinent information: www.swancc.org/recycling/cflprogram.html
ComEd's ACT website with information about reducing energy use and about the pilot CFL
recyling program: www.exeloncorp.com/ComedCare_Main/ComedCare/act/
Earth 911 website with nationwide recycling center information: www.earth911.org
State-by-state listing of disposal and recycling options: www.epa.gov/bulbrecycling/