Tuesday, May 17, 2011
LED: good bulb, bad investment.
Lynne Kiesling discusses a newly introduced LED-based light bulb by Philips. Unlike the killer CFL, the LED is harmless.
This bulb presently costs about $45, and is supposed to last 25 years.
The life estimate is plausible: I'm looking right now at an LED power indicator on my Radio Shack amplifier that has been ON most of the time since 1972. Little LEDs are eternal.
Kiesling brings up a basic fact about actual use of bulbs: We don't expect them to be permanent. Most people move every few years, so you'd have to pack up the bulbs and take them with you to justify the 25-year investment! Nobody is going to do that.
I'm past the quick-moving stage of life, but even for my simple and static little life, the investment doesn't make sense. Assuming I've got 25 good years left: the living-room ceiling fixture needs about 4 incandescents per year. I've stocked up on incandescents at 49 cents per bulb, so the cost of keeping that fixture lit for 25 years is
(4 bulbs per year * 0.49 dollars per bulb * 25 years) = 49 dollars.
About equal to one LED bulb.
But what happens if you break the LED bulb, or it fails on its own before 25 years? The investment is immediately bad. And you're not going to keep a stock of spares at that price, so you're in the dark until you can get to the store for another bulb. ¶ 7:52 AM
This bulb presently costs about $45, and is supposed to last 25 years.
The life estimate is plausible: I'm looking right now at an LED power indicator on my Radio Shack amplifier that has been ON most of the time since 1972. Little LEDs are eternal.
Kiesling brings up a basic fact about actual use of bulbs: We don't expect them to be permanent. Most people move every few years, so you'd have to pack up the bulbs and take them with you to justify the 25-year investment! Nobody is going to do that.
I'm past the quick-moving stage of life, but even for my simple and static little life, the investment doesn't make sense. Assuming I've got 25 good years left: the living-room ceiling fixture needs about 4 incandescents per year. I've stocked up on incandescents at 49 cents per bulb, so the cost of keeping that fixture lit for 25 years is
(4 bulbs per year * 0.49 dollars per bulb * 25 years) = 49 dollars.
About equal to one LED bulb.
But what happens if you break the LED bulb, or it fails on its own before 25 years? The investment is immediately bad. And you're not going to keep a stock of spares at that price, so you're in the dark until you can get to the store for another bulb. ¶ 7:52 AM
