Great stuff, Dan.
I'll add some info from a short piece we ran in HP120:
"An average-sized CFL bulb contains approximately 4 milligrams (mg)
of mercury, an amount about equal in size to the period at the end of
this sentence. Standard 4-foot-long T12 fluorescent tubes contain up
to 21 mg of mercury and modern T8 tubes with electronic ballasts can
contain about 10 mg per tube. By comparison, watch batteries contain
as much as 25 mg-the equivalent of about six CFLs. Older home
thermostats contain from 500 mg to 2 grams of mercury, or the amount
in 125 to 400 CFLs."
"The greatest source of mercury in our environment comes from burning
coal, the most common fuel used in the United States to generate
electricity. A CFL uses 75 percent less energy than an incandescent
lightbulb and lasts at least six times longer, so the mercury
emissions that result from the coal-fired electricity used to power
it are considerably lower. If you're relying on coal-fired
electricity, over a bulb's lighting lifetime, using a CFL produces an
additional 2.4 mg of mercury emissions. Contrast this with the 10 mg
of emissions produced by using a conventional incandescent bulb over
the same five-year life span. Incandescents produce more mercury
contamination than CFLs, and this is only gaseous emissions from a
typical coal-fired power plant. You also need to consider the mercury
leachate from coal mine waste and fly ash disposal. More coal needed
for electricity translates into more coal mined-resulting in more
mercury pollution."
All animals have impact. Let's reduce ours, sensibly.
Best,
Ian
At 2:43 PM -0700 12/9/08, Dan Fink wrote:
Woah, everyone. Slow down.
Snopes is indeed a great resource. However, they, like nearly every
media article cited, completely miss the point. Compact Fluorescent
bulbs contain no more mercury than do regular tube FLs, which have
been in use in homes and offices for decades. The disposal
recommendations are no different. Ask any office building
custodian--the mercury warning is printed on the base of most larger
length T8s.
Proper disposal is needed for ANY broken FL or CFL--and has been for decades.
As far as LEDs -- the reason LED lamps don't make much heat is
because they don't make much light, either. Lumen-per-watt figures
for LEDs still lag far behind FL or CFL. Yes, yes, there have been
recent announcements from LED companies -=- but take these all with
a grain of (metallic, heh heh) salt. Many of these figures take into
account only luminous efficiency, NOT real-world *total* efficiency.
AND, the high-efficiency ones are not generally available in room
lighting products yet -- they are available only as discrete LEDs.
LED lamps are extremely directional. They work fine for close-up
task lighting. But I have yet to see any LED lamp suitable for area
lighting, like a living room. I have installed and tried many, for
myself (first) and for customers. The usual response, after dark,
when they see the lighting of their living room, is --"You've got to
be kidding me. I paid $300 for THAT awful lighting?"
Give it a few years, and LEDs will be everywhere. But right now,
they are very marginal at best:
T8 FL = up to 95 lumens per watt
f40T12 FL = up to 65 lumens per watt
CFL = up to 60 lumens per watt
White LED = most ranging from 24 to 45 lumens per watt. Some have
reached 90 lumens per watt -- but are so far only available as
discrete components, not massed together in commercial lighting
fixtures.
100w Incandescent = up to 17 lumens per watt
*Again, be VERY careful of LED lumen per watt claims. All the above
numbers are actual efficiency, not luminous. Most companies that
manufacture LED home fixtures do not measure light output correctly.
Contact me off-list if you want more info on how to actually measure
efficiency.*
REF:
http://en.wikipedia.org/wiki/Fluorescent_lamp
Don Klipstein:
http://members.misty.com/don/light.html
And almost every other page on his website.
Me:
http://otherpower.com/otherpower_lighting.html
DAN FINK
Technical Director, http://www.otherpower.com/
Co-Author, "Homebrew Wind Power"
ISBN 978-0-9819201-0-8
Phil Schneider wrote:
I agree - important to understand, and LEDs are a great
alternative, with cost being the significant factor. This Snopes
article mentions the Maine DEP story:
http://www.snopes.com/medical/toxins/cfl.asp
The EPA factsheet at the end of the article has some "science"
regarding the quantity of mercury associated with a couple
different household items. It also mentions how much mercury is
released into the air by a power plant (undefined) generating
electricity. This is an interesting aspect I hadn't considered
before.
P.
*Phil Schneider*, system engineer
> Creative Energies
_
--
Ian Woofenden <[EMAIL PROTECTED]>, Senior Editor, Home Power magazine
Subscriptions: $24.95 per year PO Box 520, Ashland, OR 97520 USA
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