There is a strong movement to push people away from using incandescent lightbulbs in favor of compact flourescent bulbs in order to save energy, but the pollution profiles of these bulbs are very different. Incandescents are relatively simple to manufacture, do not involve complex electronics, and do not require mercury vapor and yet they use less energy.

My question here is whether it is more sustainable to try to cut energy usage in other ways and stick with incandescent bulbs (to avoid mercury vapor and needless electronics manufacture) or to accept the fact that even with the best recycling there is additional heavy metal pollution associated with these newer bulbs (at very least some will break before reaching the recycling center).

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    How about using LED lights?
    – elssar
    Feb 6, 2013 at 6:52
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    Related question: What is optimal “light management” with common compact fluorescent lamps?. Answers for each question partially (though not completely) answer the other question.
    – Pavel
    Feb 6, 2013 at 12:02
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    This is SO 2013 :-) Three years later, and I'm wondering what to do with the half-dozen perfectly good CFLs that I took out of my frequently-used fixtures, so that I could replace them with LEDs. Probably put them in a shoebox in the garage, next to the box of perfectly good incandescents...
    – jamesqf
    Apr 14, 2016 at 22:07
  • Incandescent light bulbs are more environmentally friendly, for some of the reasons you mentioned and more. Don't forget that you are part of the environment, too. May 26, 2020 at 18:58

1 Answer 1


Both incandescent and fluorescent are quite old technologies, and have been bettered in terms of efficiency and lifecycle impact.

Furthermore, compact fluorescents aren't the only type of fluorescents. So although the compact fluorescents are superior to incandescents anywhere with a high-carbon marginal electricity supply (so almost all the world, in 2013, bar Norway, Iceland and Bhutan), they're not in and of themselves the best in class. And remember that one of the highest resource inputs is of the glass, so an incandescent that lasts only 1000 hours is worse in many ways than a long-life bulb.

Fluorescents with a separable electronic ballast are superior to those compact fluorescents with built-in ballasts.

And there are plenty of LED lamps on the market now that give similar lumens per watt than fluorescents, and with much longer life (5-8 times as long).

For brighter lights, there are SONs with electronic ballasts, that offer very high lumens per watt too. And there are an increasing number of OLED lamps coming out too.


Incandescents are, in almost every case, a terrible option. For anywhere with a high-carbon marginal electricity supply, lamp lifetime, and lumens per watt, are your best guide as to first-order environmental impact: higher is better, for the environment.

Example lumens per watt: (note the overlaps between the ranges)

Incandescent: 15
Fluorescent (compact or otherwise): 40-100
LED: 20-100
SON (high-pressure sodium): 80-150

Theoretical maximum (pure green light): 683

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    could you provide a source for the numbers?
    – elssar
    Feb 6, 2013 at 8:38
  • In your calculation then, it is only about numbers, right? No consideration given to toxicity of mercury vapor? Feb 6, 2013 at 8:39
  • @ChrisTravers Yes, it's definitely about the numbers: it's pretty hard to measure and compare things without numbers. Lots of implicit consideration given to mercury: remember, coal power stations emit mercury too. I'll extend the answer when I get time, including sources, but for now, this answer covers the major issues.
    – 410 gone
    Feb 6, 2013 at 8:53
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    @ChrisTravers There is indirectly. In the US power companies are required to take all the renewable power that its providers put into the grid; which means that the hydropower power you're not using because you replaced your incandescent bulbs with CFL/LED lights will reduce the amount of coal/gas burned to provide other people with power, so you're still taking the same amount of fossil fuel power as if you were buying power from a company that burned it directly. Feb 6, 2013 at 14:54
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    @Chad - Agreed, but failing to properly reference quoted facts is, in many cases, worse than not providing those facts in the first place. That is why I used a comment to suggest a source which did include references. This all goes to the back it up principal, which is almost as important as the completeness principal.
    – Mark Booth
    Feb 6, 2013 at 17:11

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