I think it's pretty outstanding that in 2013 they've reached 276 lm/w. if you consider a regular edison incan bulb is only a couple of lumens per watt!
or roughly around 800 lumens for 3 watts of power (so 1 lithium battery 4.2v 3amp/h gives 0.7amp/h draw) roughly up to 4 hours of very very bright light on a single 18650 lithium battery
luminous efficacy compares a broader array of light sources to one another.
Type Overall luminous efficiency Overall luminous efficacy (lm/W)
40 W tungsten incandescent 1.9% 12.6[1]
60 W tungsten incandescent 2.1% 14.5[1]
100 W tungsten incandescent 2.6% 17.5[1]
glass halogen 2.3% 16
quartz halogen 3.5% 24
high-temperature incandescent 5.1% 35[44]
ideal black-body radiator at 4000 K (or a class K star like Arcturus) 7.0% 47.5
ideal black-body radiator at 7000 K (or a class F star like Procyon) 14% 95
ideal monochromatic 555 nm (green) source 100% 683[45]
Well, yeah. Except that 276 lm/W number is only in the lab, and probably at power levels less than 3W. Also, that's just the LED, and doesn't include losses in the power supply. Their current lightbulb is still under 100lm/W (although that has significant "cost engineering" goodness to it.)
According to this article, production LEDs are two or three years behind, at about 200lm/W (which is still pretty good!) http://ledsmagazine.com/news/10/2/16 http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2013/October/EnergyStar-bulb
Is anybody else fed up with energy saving bulbs or is it just me?
It used to be a bulb was a bulb and there were only about four types of fitting. Now there are zillions of different fittings so finding the right bulb for your lamp can be a pain.
Also while the bulb itself may save energy the lamps now don't take just one bulb they take four or more. I also really cannot believe that those bulbs that contain mercury etc. are going to be dillegenty recycled - they will be tossed in with the general waste.
I am highly skeptical of the supposed benefits of using CFLs. Take away a trivially recyclable (and for that matter, disposable) design like a light bulb, in trade for heavy metals, plastics, and chemicals. Throw out a design with resistive power consumption and replace it with one that often uses switching regulators with associated harmonics and power-factor issues. Bulbs cost pennies to make, CFLs are much more complicated. Filament burns out and becomes non-conductive, solid-state electronics have a variety of failure modes. A light bulb can work from below freezing to several hundred degrees inside an oven, but a CFL will be prone to limited output when you can see your breath, and would melt all over your lasagna if you tried to illuminate the range. You usually can't dim a CFL.....
But it's better, huh? Hm.
I'm all for using alternative technology, but not as a wholesale replacement. Maybe there are applications better suited to one or the other instead? (Like how most industrial and retail locations aren't lit by incandescents today anyway.)
While I'm not an expert on advanced LED technology, as I understand it, its ultra high efficiency is mainly for low output devices. By the time you create enough light for a room or front porch, the light-to-power ratio isn't quite as great anymore. (That still the case?)
