17

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).

WBT
  • 328
  • 1
  • 3
  • 9
Chris Travers
  • 7,039
  • 20
  • 44

1 Answers1

12

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.

Summary

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

410 gone
  • 14,714
  • 6
  • 41
  • 95
  • 1
    could you provide a source for the numbers? – elssar Feb 06 '13 at 08:38
  • In your calculation then, it is only about numbers, right? No consideration given to toxicity of mercury vapor? – Chris Travers Feb 06 '13 at 08:39
  • @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 06 '13 at 08:53
  • If the mercury consideration is assuming coal power, then what about if you live in places that get all their electricity from hydro? At that point there is really no real consideration of heavy metal pollution then, right? – Chris Travers Feb 06 '13 at 13:08
  • @elssar - The numbers in this article aren't from Wikipedia but the Wikipedia article does provide citations for most of the numbers there. – Mark Booth Feb 06 '13 at 13:51
  • 1
    @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. – Dan Is Fiddling By Firelight Feb 06 '13 at 14:54
  • @MarkBooth - SE answers are intended to be complete. Users should not have to go to a secondary site to find sources to corroborate information provided here. When the sources exists and are appropriate they should be included in the answer –  Feb 06 '13 at 16:52
  • 1
    @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 06 '13 at 17:11