LED lighting only 6 times longer life than incandescent?

Looking at small lamps to buy for the lamp post on the front walk, I was surprised to see that the much more expensive LED lamps only had a specified lifetime of 15,000 hours. The incandescent bulbs had a lifetime of 2,500 hours. So the LED lasts 6 times longer, though costs something like 30 times more. It looks like the reduced cost to power the lamp approximately compensates this, and they advantageously need less frequent changing, but still the short life is surpring.

I thought LEDs lasted much longer than this. For example, the OK indicator on my burglar alarm, which I can see from here, has been on 180,000 hours now.

Any idea why so short?

I assume this was a “white” LED? The lifetime of these devices is usually given at the point where their brightness is reduced to 50% of it’s initial value. The device itself may last many times that long, but it will get progressively dimmer. “Lumen maintenance” is a big issue in LED lighting, and we are likely to see some significant increase in white LED lifetimes in the near future.

BTW - here’s a PDF on LED lumen maintenance: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds_aug16_r1.pdf

Re relative lifetimes another factor to consider is that LEDs used in high performance flashlights and other devices where they are actually producing usable light are typically being driven closer to their performance limits and are running far, far hotter than the LEDs used as indicator lights etc.

Here’s a comparison between CFL, incandescent and LED lights

Well, it makes sense. Thanks!