Standard A19 format light bulbs, found today in most lamps and luminaires, are now available in LED versions that retail between $20 and $40 per 40-W- or 60-W-equivalent bulb. Some bulbs are dimmable, some not, and some only with specific dimmers. They all advertise 25,000 to 50,000 hours’ expected lifetime, based on three to four hours’ daily usage. If you use them appropriately and sparingly, you might expect your light bulbs to outlive you.
But why are the bulbs so expensive? Do they provide real value for the price? And why are some bulbs twice the price of the others?
In our scientific quest for answers, MuAnalysis Inc. tore apart five A19 LED bulbs: a Philips 60-W equivalent, at 12.5 W and 800 lumens, and 40-w equivalents from Feit, GE, Pharox and Sylvania. Our examinations of the five bulbs raised still more questions. (For the full report, go to www.muanalysis.com.)
Each of the bulbs comes in a specially designed package, unlike tungsten filament and CFL bulbs, which ship in nondescript shrink wrap. The fancy packaging adds to the overall cost.
These bulbs clearly are not yet positioned as commodity items; they are expensive and are expected to last. But the price of electronic gadgets has dropped so much of late that longevity is no longer the main concern. So why is a common light bulb more expensive to buy than a cheap digital camera?
Looks count in a category as simple as light bulbs, and each of the bulbs we examined has a unique appearance. For example, the GE bulb has a ceramic neck and fins and a glass bulb, and is more costly than those using plastic and metal.
All of the bulbs have a small printed-circuit board contained within the neck, relying heavily on large electrolytic capacitors and transformers. The reliability factor of LEDs has increased tremendously. But how long will electrolytic capacitors perform under such hot operating conditions?
All of the bulbs have a small pc board within the neck, relying heavily on large electrolytic capacitors and transformers.
I don't see why the electronics needs electrolytics. If you full wave rectify the AC, it should be possible to operate the LEDs only during each half-cycle - at 100 HZ the flicker should not be visible? You could still have a switch mode inverter running to power a string of LEDs at several tens or '00s of Kc during each half-cycle? Tony41, or any other hot shot designers, could you comment?
I have been disappointed in both the cost and the working usefulness of the LED bulbs. Another thing that bothered me was (at least one brand) the lamp base was hot...seems to me if a light is generating heat it is wasting energy. I am amazed at the current cost for these bulbs and not at all happy with CFLs! The "working usefulness" issue for me is the directional-ness of these bulbs. They may work great in a reading lamp fixture or an overhead can (ignoring the heat concern) but for general lamp fixture use such as ceiling dome lights, floor/table lamps they do not shine the light in the right direction!! I am not yet going to use these and currently must suffer with CFLs to keep my electric costs down. At least with CFLs they are cheap.
Great article! I also deeply agree with Tony41.
These new LED bulbs are the same kind of trash as currently available CFL. They are intended (supposedly) to replace standard incandescent bulbs. As most bulbs are installed hanging from the ceiling, usually inside a recess, you have your fragile electrolytic cap and other components subjected to the higher possible temp! Very smart engineering!!!
And c'mom, 3 to 4 hours a day? I have a couple of lamps around my house installed for safety reasons that stays on from sunset to sunrise (~7 PM to ~6 AM). You can imagine how will be the lifespan of these electronics, staying hot for 10+ hours in a row everyday...
I have been developing LED lights for many years. I was the first to put them behind a LCD large flat screen for outdoor advertising in direct sunlight.
I would not purchase any of the LED light bulbs on the market today. The LED's may last a long time but the plastics and power supply components will not.
I designed and developed my own LED lights for my home because I could not find one I would purchase. I use long life components as well as RGB LED's to give me the color spectrum needed for proper lighting. I have also been able to get a bright light that is brighter than an equivalent 100 watt light bulb. I have experimented with quantum dots but it dimes the light too much to get a color shift.
I can dim them just by turning off a few LED’s at a time with a switch. I have an LED module that is 2” X 2” X 1/4” thick plugs directly into 120VAC as well.
I can also power them from batteries charged by a solar panel. During a power outage I have lights when all around me are black.
I can see why LED lighting is failing to gain traction in the US. I have been unemployed for over two years and cannot get a job, however just working at home I seem to be well ahead of all of you.
Well done, interesting analysis, electrolytics are the main problem with CFL, as you state these LED will be poised with this too.
ACRICHE LED with direct AC input design are more quiet solutions, I have already 3 years of full time running,70 ACRICHE lamps involved and no defect. Control after one year shows no decrease.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.