jharkin said:
I don't see the benefit of the LED other than the lifetime. 25% less watts, but at least 30% less light output (lumens) . So its practically a wash in terms of lumens per watt. For over 10x the price?
What am I not getting?
-Jeremy
Current technology warm-white LEDs and CFLs have nearly identical total lumens per watt, so in most applications the energy cost to run is a toss-up. (Cool-white LEDs and CFLs are both 15-25% better lumens/watt than their warm white counterparts). With the longer life, one might make the case that LEDs are a better deal (over a 10 year period), but this assumes that the lifetimes are realized. As with early CFLs (e.g. 10 years ago), the market if filled with low quality units that can fail prematurely or rapidly fade to a unusable level of brightness.
Techies and investors are excited about LEDs because they have a _theoretical_ potential for much higher lumens/watt than CFL, that has been largely realized in the lab, but not yet translated to production-scale long-life commercial products. As CFL is a mature technology, no one expects much future improvement there, so LEDs will eventually 'win the race'. IMO it took, what, 50 years for fluorescents to get to the current point of displacing Edison bulbs, due to color/function/form factor reasons. Will LEDs take 50 years to knock out CFLs?
Some niche markets exist, such as when the application favors a very small unit or power (auto/decoration/night light), or directionality (task/flood/display lighting) or dimming. Optical inefficiencies in CFL 'flood' bulbs give them a disappointing lumen or lux/watt--if you ever tried them, you probably noticed that. For all these applications, current LEDs from quality vendors are the way to go over mini-incandescents/halogens or CFL floods.
Both CFLs and LEDs need to convert 120 to their operating voltage--so that is a cost/ineff hit to both. IIRC, all current lighting technology in the labs are running no better than 30% efficiency turning electrical energy to white light, so there will be plenty of heat generation from these bulbs. CFLs do get warm, but are naturally large and so dissipate heat readily. LEDs are going to produce a similar waste heat/lumen, but their small size means a separate heat sink if required so they don't fry. Indeed, heat management is a major difference b/w quality and cheap products--poor heat sinking leads to thermal shutdown/dimming, faster output fade and premature failure (again, much like early CFLs used in can lights).