Compact Fluorescent Feedback

The Compact Fluorescent Article prompted a variety of opinions and viewpoints! I had no idea these lightbulbs were so controversial! Plus! Math!

I'm sure someone pointed this out already, but with the compact fluorescent light bulb to car comparison, you're opening yourself up to the criticism on the price. Lets take the analogy further, using the following costs:

1 new 100watt equivalent/23 watt CFL = $3.17 each

1 new 100 watt incandescent = $ .62 each

Now, an incandescent bulb is the standard, the average for most people - and if you set the average price of a new car at say $15,000 then the equivalent price for the new, super efficient CFL car would be approx $76,000.

Now this car, as you pointed out, would get great mileage, but is it a move that most people would make - even if they could? I don't know.
Going further, if your $15,000 incandescent-mobile gets 22 mpg and your $76,000 CFL-mobile gets 95 mpg and we use your earlier computations for gas mileage savings in a year of the average being 15,000 miles and 3.03 a gallon for gas then it works out like this:

incandescent mobile: 15,000 miles at 22 mpg = 681 gallons of gas for a yearly cost of $2065
CFL mobile: 15,000 miles at 95 mpg = 157 gallons of gas for a yearly cost of $478. That means the yearly difference in fuel costs of $1587

Since the difference in purchase price is $61,000 - we can figure out that it would take approx 38 years to make back the extra money you spent on the CFL mobile.

But of course, we've gone over the freaking rainbow and taken the comparison way past the point of it making any logical sense, so all of this means absolutely nothing. But anyway, it made me flex my rusty algebra muscles some...

Warden Streets

Hello, I love your site but I would like you to post an update to the CFL post. These bicycles contain mercury and must be disposed properly . If they are improperly disposed there may zero net gain for the environment.

Carlessly tossing your CFL in the municipal trash will put a tiny bit of mercury into the land fill. Multiply this action by everyone of your friends and neighbors that use the same land fill and you have a problem on your hands. A mercury release in (or from) a land fill may equal the damage done by the extra carbon released from requiring more energy to power an incandescent.

Getting everyone to switch to CFL = Good
Getting everyone to dispose of them properly = Better
Writing a grant to obtain funds to distribute CFL bulbs to the first 500 people who ask for one that also promise to dispose of the bulb properly = Saintly

You should also mention that recent advances in CFL technology have done away with the strange light that the older models used to produce.

Seth Heller


Had an email almost written up about the article on MPGs on a car, but decided that it didn't really contain any substance, so I deleted it (the gist was that the difference between 26 and 27mpg on a car is secondary to one's driving habits on gas usage).

But your article on CF bulbs prompts me to write in and actually click 'send'.

Energy cost is measured in many ways: Cost of manufacturing, cost of using, and cost (to the environment) of disposal. For instance, it takes much energy to make a plastic bag, but costs the consumer nothing to use it. Disposal cost is low as bags are light, and while taking dozens of years to biodegrade, will. Incandescent bulbs cost (energywise) more than plastic bags to manucture, and also cost the consumer in their electricity bill. Disposal cost is marginal, as there aren't any toxic chemicals in their production. CF bulbs cost the most to manufacture (really, just a guess based on the increased price to purchase one, but also confirmed by the wikipedia article, cost less to the consumer (energywise), but have the greatest disposal cost.

While I agree that we should all switch to CF wherever and whenever possible, I disagree that we should toss out working incandescent bulbs, as that just accelerates the disposal cost of incandescents. As it is not clear what the overall environmental (energy and disposal) cost of the CF bulbs are, I'd stop short of recommending disposing of all existing incandescents right away.

On a side note, I'm not sure how your state will handle banning incandescents...there are still a few usages for those, mainly as dimmers, replacement christmas lights (I know, everyone should switch to LEDs), and refrigerator lights. I'm sure the legislation does accomodate exceptions such as these...I just couldn't find out with a quick google search.


I don't mean to disagree with you on compact fluorescent bulbs (I've been putting in my apartment a little at a time), but I think your article needs a little more balance. I'm a cyclist, so I completely agree that crossing Australia would be better on a bike than on foot, but if I had a choice, I'd take an airplane!!

Your illustration of the bulbs with MPG stickers is true, but you have to show the bottom of the sticker! You know, the part were you can compare the price too. Using your car analogy:

For the old, crusty, heat producing incandescent bulbs, let's say I buy your average American gas guzzler, a Chevy Suburban.

Gallon of Gas: $3
MPG: 18
MSRP: $39,000
Expected life span: 150,000 miles

So total price of ownership is:

3 $/gallon
--------------- * 150000 miles + $39000
18 miles/gallon

That's about $64,000 for the life of the car (not counting tires, oil changes, pine scented air fresheners, etc.) And when the car is all used up, I can drive it out to the scrap yard, get $50 for the steel and go buy another Suburban. So ultimately I spend 42.6 cents a mile.

Now, for the new, cool, spirally CF bulb, you buy a sleek, super efficient, fantasy hybrid car. (Using the numbers for the Suburban, and the comparison between CF and incandescent bulbs.)

Gallon of Gas: $3
MPG: 72
MSRP: $1,000,000
Expected life span: 1,500,000 miles

Whoa? How much? Yeah. Pretty pricy. But it runs for a really long time. Let's see if it makes a difference.

3 $/gallon
--------------- * 1500000 miles + $1000000
72 miles/gallon

Your total expense is $1,062,500 (not counting fresh flowers, Starbuck's, Darwin fish stickers, etc.) And when the car is all used up, we have to pay a $10,000 fee for the disposal of the toxic battery acid. (You do know that those CF bulbs have toxic mercury in them. You can't just toss them in the trash bin!) So you end up with 71.5 cents per mile. Almost twice the cost of the Suburban.

Granted I had to use ten Suburbans while you only had to buy one Prius xTreme and I did consume a lot more fossil fuel than you did. But does that really offset the cost?

Here's where I got my comparison numbers.

The incandescent:
Electricity cost: $.06 per kWH
Usage: .060 kWH
Replacement cost: $.39 each
Life span: 1000 hours

The CF:
Electricity cost: $.06 per kWH
Usage: .015 kWH
Replacement cost: $10 each (This is my local price rather than the $14 reported in the link above.)
Life span: 10000 hours

G'day Rob,

Love your site, and it's good to see some one being passionate about practical ways that we can save the environment / consume less energy. But I feel inclined to add some 'background' to your CFL piece. They aren't as great for the environment as you think, and if used incorrectly they are much worse...

So, where shouldn't you use CFL's? Any place where they are tuned on infrequently and for a short periods of time. This might be a pantry cupboard, toilet, inside a refrigerator.

The CFL's don't like being power cycled all that often. The filaments are heated at each start, (run at high current, as opposed to the low current they draw when running) and this shortens their life. Also, the electronics used in the ballast are stressed at each power cycle (like most things) and this can shorten their life.

  • Any high temperature environment. This starts with the obvious, like the light inside your oven, but also includes a lot of enclosed light fittings. The electronics in the ballast tend to be rated to about 45 degrees Celsius. If a light fitting has little air flow this can be exceeded (yes, CFL's put out less heat that incandescent *but* they do put out some heat) and the life of the CFL will suffer.
  • Any thing that needs lighting with a full colour spectrum. CFL's lack certain colours of the spectrum and can make things appear a different colour to what they are (lot's of green things can look blue, orange things red etc). You do have better CFL's with more colours than in the past, but they are still lacking.
  • They cannot be dimmed like incandescent, eliminating their use as mood lighting etc.

Okay, so why is a short life cycle a bad thing, aside from the cost?
It's all to do with energy payback. It takes more energy to produce a CFL than an incandescent bulb, when you factor in the electronics, the moulded plastics, the phosphors etc. So if you kill one quickly, you end up costing the environment more in net energy usage. (Energy Payback is a reason why Photoelectric Solar Power isn't a good thing. But that's another topic for another day).

An incandescent is easily recycled. It's all metal and glass. Piece of cake. A CFL is *nasty* to recycle. Plastics, Electronics, Mercury Vapour. Ugh.

Now, don't think I'm against CFL's - I use them myself. Stick to using them in large areas that remain switched n for long periods of time (hey, that's also your largest sources of lighting energy use!) such as your kitchen, living area etc. Things like the garage should be lit with good old fashioned fluorescent battens etc.

Anyway, that my $0.02 worth. Keep up the good work!

Simon Ludborzs
Electronics Hardware Engineer

With your recent article, I thought you'd be interested in this for sure:

It's the banning of incandescents! Actually, more appropriately, the eventual phase-out of incandescents.

Also, CFLs are not without their issues. They have a lot of mercury in them and that makes disposal a problem, especially if everyone was using them. From the link: "But as WND reported, the presence of small amounts of highly toxic mercury in CFLs poses problems for consumers when breakage occurs and for disposal when bulbs eventually burn out. The potential environmental hazard created by the mass introduction of billions of CFLs with few disposal sites and a public unfamiliar with the risks is great." They are a heck of a lot pricier. And like fluroscent tubes, the stuff inside (gas, powdery stuff) is pretty unhealthy. But, I can't argue that they aren't a big step in the right direction of energy conservation! I typically replace the most used lights in my house with them, and use the old style for the lights that I turn off regularly or see little use. For example, my porch light and outdoor garage lights are CFLs as are my living room overhead lights.


Hey Rob,

Long time reader, truly enjoy your site. I noticed your post on CFL’s today, and wanted to pass this along. FatWallet has a deal up where CFL bulbs are on sale from $4.88 down to $0.98. In-store pickup is crucial as Lowes charges an arm and leg to ship. I went by yesterday, was in-and-out in 3 minutes with my printed out confirmation; picked up 60 haha.

Once you enter your ZIP code on the Lowes site, it shows the discounted price.

Thanks for the great site!
Will Rinehart

(I replaced Will's slickdeals link with a fatwallet link, because Fatwallet is a sponsor, and slickdeals is totally illegible.)


Thanks for your article describing the benefits of 95 mpg (are those Canadian or American Miles or Gallons to which you are referring?) lighting.

For a Science Club article, perhaps a good followup would be to examine the cost of disposal/recycling of CFLs (and their Mercury content) vs. Incandescents.

There are no doubts that countless power plants near Sacramento will not have to be built if everyone changes over to these bulbs, but I have often wondered what the ecological/financial cost is of disposal of such bulbs. Is it REALLY worth it, to the environment and building power plants and everything else to switch over, or is this some government hoax to support this industr




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