With ‘modern’ CFD (or sometimes called CFL) and halogen light bulbs, apart from the fact they are supposed to burn less wattage in order to product more light, they are also supposed to have amazing lifetimes before they fail—compared to the low-tech incandescent bulbs they replace.
With CFDs the packaging typically promises something between 6,000 and 10,000 hours.
Oh sure! As if!
At six hours per day a CFL bulb that is supposed to last 6,000 hours should last around 1,000 days. Which is about 2.75 years if you used it every day for those six hours.
Seriously, if we get six months out of a CFL in our house then that would be a miracle.
And the even ‘newer’ 30 percent power saving halogen bulbs that have become popular over the last couple of years—because it turns out CFLs are somewhat dangerous due to cancer causing UV emissions and use of mercury—are not much better.
The packaging with the halogen bulbs typically tells you the bulb will last two years with average use. Again, we rarely get more than about six months from these as well. We are constantly buying six packs of these bulbs.
Yet, as I recall, the old low-tech incandescent bulbs rarely ever needed replacing. I have two of these in the lights at the front of our house that the builder put in 20 years ago when the house was built. And despite being out in the weather (they have no shroud covering them), being covered in grime (see picture), being accidently left on overnight many many times, they are both still there and both still working!
Right now the latest-and-greatest leading-edge LED light bulbs are starting to emerge. At this stage they are generally only available at specialist lighting stores and they only go up to 60 watts (comparative). These are serious power saving bulbs that can produce the equivalent number of lumens (amount of light) with a third of the power used by a halogen bulb. At about $60 each they are a bit expensive to use everywhere in the house at this stage but—as the price comes down—I guess we will all shortly be replacing our CFL and halogen bulbs with LED bulbs.
I just hope they last longer than the CFLs and the halogens that came before them.