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Compact Fluorescent Bulbs
November 1, 2007 - 2:33pm
The calculation:
300 million Americans x 9.5 (tons of greenhouse gases saved per CFL bulb) = 2.85 billion tons
Because there are 8,760 hours per year, it would take about 3.42 years to burn through one 10,000-hour CFL bulb (burning it at a rate of 8 hours per day).
So, dividing 2.85 billion tons by 3.42 years = a reduction of 0.8322 billion tons of greenhouse gas produced annually by using the CFL bulbs.
According to this US Department of Energy website, America produces about 6.008 billion metric tons of carbon dioxide (and that that represents 84% of all greenhouse gases in America). So, total American greenhouse gases are about 7.152 billion tons annually.
That would indicate that the “CFL bulb savings” of 0.8322 billion tons per year would represent a reduction in total greenhouse gas production of more than 10%.
These are rough numbers but my question is: Could the savings be that substantial???
I’ve been swapping out incandescent bulbs for CFL bulbs. Besides, these particular CFL bulbs produce a light that is much more like sunlight than incandescent bulbs and makes for better reading light (IMO).
I'm pretty skeptical about those figures myself. I suspect a lot of it is theoretical calculations that bear no relationship to reality.
For example, in many cases (in Canada at least), the reduced heat output of the CFL "bulbs" (we're gonna need a new word) compared with the incandescents will have to be made up by other heat sources - most of which involve burning fossil fuels.
ETA: I note that 9.5 tons of CO2 is about half the annual per capita emissions in Canada and the US. If that much could be saved by switching a single light bulb, we could solve the whole climate crisis using light bulbs alone.
I have my doubts. For one thing, we use 40 & 60 watt bulbs (or their flourescent equivolents). For another, bulbs get broken. Third, even flourescents burn out; they may last longer, but they do fail.
I'm suspect about the polution during manufacture and after failure. These days, there is emphasis on greenhouse gases, but eventually these things are going to wind up in the dump. What then?
The 9.5 figure assumes that a bulb would be burned out after one year. That's where I (arbitrarily) assumed a bulb burning for eight hours per day, such that a 10,000-hour CFL would last for 3.42 years, or an average savings of 2.78 tons per year per person (or 14.6% of total per-person GHG production).
I'm going to have to research this some more (and understand the whole lifecycle of the CFL versus incandescent--from production, use, and disposal).
So if each of us switches just seven light bulbs over to CFL's, we would reduce our personal emissions footprint below zero!
Exactly!! [img]wink.gif" border="0[/img]
Like I send, I need to do some more research about the whole lifecycle of CFL "bulbs".
http://www.rabble.ca/babble/ultimatebb.cgi?ubb=get_topic&f=45&t=000370&p=
Though it's being used in cars, Christmas lights and now, apparently, street lighting, I'm not aware of any LED units, yet, to replace the incandescent bulb.
From Costco, my son just purchased an LED FLASHLIGHT with a hand generator attached and combining an AM/FM radio. ($10,00) So, what could an LED light bulb cost?
This appears to be a reasonably good discussion about the importance of recycling CFLs because they contain a minute amount of mercury.
Although I need to do more reading, a brief perusal of various websites appears to indicate that using CFLs is clearly a net positive (relative to incandescent bulbs).
So a 24 watt bulb would use about 48 kilowatt per year (burning about 200hrs/year), or about 36 lbs of coal, producing about 110 lbs of CO2.
A 100 watt bulb would use about four times more.
And produce about 440 lbs of CO2. Multiply that by 300 million and you get to about 70 million tons of CO2.
The reduction in CO2, when switching bulbs would be about 52 million tons. Add to that the energy required to produce and deliver the coal to the power plant and to deliver the electricity to the light bulb, and the Sierra Club number seems to be about right.
Those LED lights use very little electricity.
A few years ago I bought some LED christmas light strings, and installed them in the barn and hayloft to just give enough light to be able to do the chores and as a night light. Those four string use only about 6 watts when on. As oposed to the five 60 watt bulbs that normally where used. The compact fluorecent light do not work very well in the colder barn in winter.
So how can a CFL bulb reduce that 440 pounds by 9.5 tons?
Personally I do not see the 9,5 tons either. That is why I made this rough calculation and it seems to jive with the Sierra number, from Sven's last post.
Maybe they calculated it based on some very inefficient electric power generator.
I found this quote about mercury in CFLs - link and more info; CO2 calculations too:
"CFLs contain a small amount of mercury and should be disposed of properly, ideally recycled. A link and more information regarding mercury in CFLs, including proper disposal options and what to do if a bulb breaks"....
....can be found near the bottom of the page at this link:
CFL Disposal — Closing the loop:
The LED bulb they used was a familiar screw in mount, like incandescents and compact fluorescents. The small LED bulbs were arranged in a gang around a framework.
I think it used 1% of the electricity of a comparable incandescent, and the bulb did not fail after all others burned out in the "on-off" test.
I have been looking for such bulbs, but have not found any to date.
My 50-plus virus intrusions prevent me from posting the link. Perhaps you or another poster is able to.
The concern is real, but just to put things in perspective, if you live in a place where coal is a major source of energy, you might actually be producing a net reduction in the amount of mercury released into the environment, even if you're naughty and just throw the lamp in the garbage. The reason is that most coal also contains mercury, and burning it releases that into the atmosphere.
Of course, LEDs would be even better, and I hope that they become available soon.
Lots of info here. Open image "household lighting" to get costs.
Read an article (2006) Re: Walmart making big switch to LED in its stores for environment AND economy.
ETA
Since there are several steps to get to that price list, here we go:
http://www.superbrightleds.com/cgi-bin/store/commerce.cgi?product=MR16
[ 07 November 2007: Message edited by: bliter ]
As I get older, the more light I need (or at least prefer) for reading. The number of lumens produced by those LED lights is very, very low for reading purposes (I think the max was 100 lumens for one of the LED bulbs listed on the link provided by blither).
A tiny 15 watt incandescent bulb (120v) will produce more lumens than that (110 lumens). In contrast, a 14w CFL will produce a whopping 800 lumens (which is roughly equivalent to using a 60 watt incandescent).
So, while the energy-consumption rate of LEDs is incredibly low, the light quallity may not be practical for some lighting applications, like reading.
Aside from lumens and energy-consumption rates, the CFLs that I've been purchasing (principally for reading lights), in contrast to incandescent bulbs and especially LED light, very closely replicate sunlight. Which, again, makes reading easier for my getting-older eyes.
Try a different CFL-- they provide excellent light but if you had a poor one then that could explain things.
This would be true for the period of the year in which heat is used--but if air conditioning is used in the summer, incandescent would be an additional energy drain.
I don't know if anyone has done calculations on these variables.
Outdoor lighting, of course, is the simple calculation.
LEDs are the future of efficient lighting especially with recent r&d advances and better "white" light production.
I currently use mostly CFLs
The heating season in much of Canada is about 8 months and the air conditioning season is about 3. The requirement for heating during most of those 8 months is pretty constant - more so than the requirement for A/C in the summer.
Also, because of Daylight Saving and the 16 or more hours of daylight in northern latitudes (24 in the Arctic!) there should be less demand for artificial lighting in the summer than in the winter.
Also, people spend less time indoors in summer.
All in all, the vast majority of the heat given off by incandescent bulbs in Canada is put to good use.
Still, I can think of a few places in the house where they'd have application: My back hall has a five bulb chandelier, currently fitted with compact fluorescents. Because the area is small, the chandelier relatively low, 30w may be enough for that area. And that light stays on much of the time.
Same with the light above the stove, and the stairs light. 30w is enough for getting around in the dark.
Those back yard solar powered garden lights have come along ways in terms of reliability and light quality in just the past few years. I suspect LED's for household use-- something that will give off the 60w incandescent equivalent, is not too far off.
Just imagine how much fuel they could save if we replaced our car lights with those. And a lot easier on the battery.
What else is in your "fad" collection? Electricity? [img]biggrin.gif" border="0[/img]
Okay, so to seriously answer you now about the fluorescents: I am also not crazy about them, although I do use them. I'm replacing each incandescent with a fluorescent as they burn out so that I don't have such a huge hit to the wallet all at once.
Anyhow, the thing I don't like about fluorescents is that they're very harsh and institutional. I'm sure the technology will get better so that they get a bit of a "warmer" feel to them.
I also have a friend who gets migraines, and fluorescent lighting is a HUGE trigger for migraines and all-around malaise. To the point where she actually has fluorescent lighting taken out of her workspace at her job and she uses smaller lamps that use incandescents.
I guess we're either going to have to get over that sort of thing if it ails us, depend on natural selection to weed out the people who are sensitive to fluorescent light, or (a more sensible option) find a way to make fluorescent lighting technology better so that everyone can use it.