Hi, I'd just like to express a small opinion here on how the efficiency of LEDs have made lighting available to me and perhaps many others when less efficient incandescents have not really been an option for "micro off-grid" lifestyle.
I've lived for 3 years now without electricity, reading at night with cheap solar charged leds (similar to those people light their outdoor paths with) and candlelight. It's been pretty challenging, but the led technology made it possible to have little easy light at night. I think there's a lot of people in this situation, maybe not in our country.
I now have a small 750w solar system. I live in southeast Ohio, and in the heavy overcast days of winter (which can last weeks) it is not uncommon to trickle in around 15 watts throughout the 6 hour solar window, that's with 3 250w panels. Sometimes there's not even enough light to trigger the charge controller out of its "resting" phase on really bad days.
Point being here is that incandescent lighting, while arguably "better" (based on all this really great evidence and dissection of components) is really only an option for people grid-tied, or with a substantial off-grid system, or perhaps just a more reliably sunny climate.
For some of us, the wattage efficiency of LEDs doesn't have have anything to do with what seems to some as a silly margin of a few dimes on the power bill. The revolution in the difference of watts from 60w to 4w means whether or not I can have lighting without worrying about substantial discharge of my tiny battery bank.
I've also known folks to conveniently power LEDs from car batteries, then start their car the next day on the same charge. Point is that this technology has made lighting available for folks that would otherwise be without.