[SustainableTompkins] How Many Lightbulbs Does it Take to Change the World?

[Joel and Sarah Gagnon]

We just recently burned out the first CFL we installed. It was an 
"earthlight" by Phillips. It was on for at least 3 hours a day for over 10 
years,  but it was not turned off and on frequently. This CFL wasn't very 
compact either. It barely fit in the table lamp into which we installed it. 
Meanwhile, more recent spiral fluorescent bulbs installed in the kitchen 
ceiling light burned out after only a couple of years. That fixture is 
enclosed, so it runs hotter, and it is frequently turned off and on, so 
temperature effects and frequent cycling are confounded. Another CFL in a 
ceiling application in an adjoining room, but unenclosed, shows signs of 
failing after very little on time, but frequent cycling.

It is a whole lot easier to test incandescents, given their shorter product 
life claims. The effects of cycling would be interesting to check, as would 
the effects of temperature on both performance and longevity. It is the 
kind of evaluation you expect out of the Consumers' Union, publishers of 
"Consumer Reports", but I haven't seen anything there.The following review 
article is a good starting place for more information, and covers both the 
longevity and brightness issues: 
http://mail.mtprog.com/CD_Layout/Day_2_22.06.06/1115-1300/ID109_Skumatz3_final.pdf#search=%22CFL%20evaluation%22 


Joel

  At 03:31 PM 9/1/06 -0400, you wrote:
>The article on compact fluorescent lightbulbs (CFLs) brings to
>mind a couple of questions I've been wondering about for quite a
>while.
>
>My wife and I switched to CFLs (the new spiral kind, not the old
>style) about four years ago, replacing just about every tungsten
>bulb in the house with a CFL.  We did indeed save a lot of
>electricity, but we also found that CFLs (yes, the new ones) don't
>last anywhere near as long as claimed.  In actual service, we're
>lucky to get a couple of years out of them; the statement in the
>article that "compact fluorescents, even in heavy use, last 5, 7,
>10 years" simply isn't true as far as I can tell.
>
>It's also not true that "compact fluorescents emit the same light
>as classic incandescents." Like all fluorescents, CFLs don't put
>out a complete spectrum; they put out a couple of sharp spikes at
>certain wavelengths, the combination of which is carefully
>engineered to give an impression of (more or less) white light
>that works OK until you try to judge color combinations of
>clothing or makeup or artwork, at which point the missing
>wavelengths make accurate assessments almost impossible.
>Incandescent bulbs, while having a color temperature much warmer
>than daylight (2700-3200 degrees Kelvin vs. 5000-5500 for
>daylight), do put out a continuous spectrum, which is why you'll
>always see incandescents used at makeup tables and in museums.
>(Some people believe that the discontinuous spectral output of
>fluorescents is actually bad for you, but I haven't noticed any
>deleterious effects from using them at night.  Working all day in
>a room lit by nothing but CFLs, with no supplementary window
>light, might be a different matter.)
>
>Another claim for CFLs that isn't true is that they "use 75% or
>80% less electricity."  If this were so, a CFL that used 15 watts
>would give off as much light as a tungsten bulb that used four to
>five times as much, that is, 60 to 75 watts.  In reality, CFLs
>give off as much usable light as a bulb rated about three times as
>much, not four or five.  (Yeah, I know that the measured lumens
>from a 15 watt CFL are the same as from a 60 watt incandescent.
>Try working in a room lit by one and then the other and see for
>yourself.  I think that the people who are happy substituting a 15
>watt CFL for a 60 watt incandescent have just discovered that they
>can get by with a little less light than they thought they could
>-- which is an important and useful discovery to make, but not
>what's being claimed.)  I read somewhere a couple of years ago of
>a proposal to require ads for CFLs to use the factor of three
>rather than the factor of four that you always see on packages,
>but this seems not to have gone anywhere.
>
>None of this is to question the advisability of replacing
>incandescents with CFLs wherever appropriate; the question is,
>what are the appropriate uses for them?  And this leads me back to
>the longevity issue.  My suspicion is that the longevity of CFLs
>is directly related to how often they are switched on and off.  A
>CFL that can easily deliver its rated life of 10,000 hours if left
>on continuously is unlikely to survive 60,000 duty cycles of 10
>minutes each.  (This is true of most electrical devices.)  So my
>first question to this group is: Has anyone produced guidelines
>for the breakeven point between fluorescent and incandescent bulbs
>depending on how long they are left on each time?  My hunch is
>that the light in a closet that's rarely on longer than a minute
>at a time is properly served by an incandescent, whereas the light
>in an office that's left on for hours at a time is properly served
>by a fluorescent, but where's the dividing line?
>
>My second question is a larger one.  Has anyone done a *complete*
>energy accounting comparison of fluorescents vs. incandescents --
>one that includes not just the energy used to run CFLs, but also
>the energy used to produce the raw ingredients, manufacture them
>(taking into account the environmental costs of the exotic
>materials used to produce the electronic components), transport
>them all the way from China (which is taken as a given in the
>dollar cost comparisons), and finally dispose of them (including
>dealing properly with the poisonous materials they contain)?
>
>Around our house, we'll no doubt dutifully continue to use CFLs
>where there's even a chance that they make sense, but without a
>complete energy accounting, I'll continue to wonder whether we're
>not just externalizing some essential input, like the folks who
>believe that ethanol from corn represents a net energy gain.
>
>Jon
>
>
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