WC Archive

Farhad Manjoo at Salon has a great piece in today's issue (if you're not a subscriber, a brief ad will play) looking at the inefficiency-masked-in-familiarity of the modern light bulb, and what we can do about it. He talks about the origins of the modern version of the compact flourescent bulb, but focuses most of his attention on LEDs as an alternative -- something we were on top of that several months ago.

Why is getting rid of the incandescent bulb a good idea?

Replacing incandescents with more efficient lighting will undoubtedly be good for the planet. According to researchers at the Sandia Labs, one-fifth of all the electricity produced in the world is used for lighting. Doubling the average efficiency of white-light lamps -- through LEDs or fluorescents -- could reduce global electricity consumption by 10 percent and carbon emissions by 200 million tons a year.

One interesting point of comparison mentioned in the article is the lumens-per-watt rating for different lighting types. Incandescent bulbs rate about 12 lumens per watt. Halogen are somewhat more efficient, coming in at 15-17 lumens. A "warm white" LED, which produces light similar to incandescent bulbs, produces 22-25 lumens/watt; a "cool white" LED, which is a harsher white more akin to an old-style flourescent, rates about 35 lumens. Flourescent lights, though, remain the champions, putting out (depending upon type) 50-100 lumens for every watt consumed.

Since incandescents use 90% of their energy to put out heat, not light, adopting alternative light sources wherever possible is a pretty good idea.