Alex Vafiadis
Why would you buy an LED bulb that is only 84% more efficient than incandescent when the current mini fluorescent bulbs use one fifth the power of incandescents which makes them 400% more efficient.
Jon A.
Hopefully the electronics in the ballast don't turn out to be the weak point for these bulbs like they were for so many CFLs.
Alex, your math is off. The 60W LED bulb uses 9.5 watts of power, making it 630% more efficient than incandescent bulbs, and the 40W uses 6 watts, making it 667% more efficient. Jon, LED bulbs use a power supply that is not a ballast, but early LED bulbs had problems with the lifespan of the power supplies. I bought three of the early bulbs five years ago and they all died within two years. The newer bulbs are supposedly tested to prevent this problem, but only time will tell. The life of the power supplies is still going to be the limiting factor of the bulb life, not the lifetime of the LEDs themselves.
Alex.... 9.5 watt for a 60w equivalent bulb is less than 1/6th the power. if I'm not mistaken 1/6th is less than 1/5th. Therefore the LED bulb uses less than the CFL
These bulbs are also dimable!!. Cree's home page has a pdf which lists which dimmers these bulbs are compatible with. The 40W equiv bulb draws 6W and 60W equiv draws 9W while CFLs would draw about 10W & 15W respectively. The 84% reference comes from the site's poor wording. "It looks and works like what it is. A light bulb. But unlike incandescent bulbs, it's 84% more efficient and lasts 25 times longer." would be better worded as "It looks and works like what it is. A light bulb. But unlike incandescent bulbs, it lasts 25 times longer and is 84% more efficient than a CFL"
I own about a dozen LED bulbs (yeah, it's nerdy, I know). I recently picked up two 60 Watt equivalent bulbs at Home Depot for $13 ea over the weekend. In three respects, these bulbs are better than the Philips AmbientLED bulbs. 1. They look "normal" in fixtures that expose the bare bulb. 2. They turn on quicker. I have the Cree next to two of the Philips bulbs in a bathroom fixture. The Cree lights up about 1/4 second faster (guessing on the time). 3. The Cree is 20-30% less expensive. The overall color of the Philips might be a bit better. All in all, I really LOVE that we have good options. Using LED bulbs is small scale, lazy-man environmental action! I actually get a decent financial return for doing the "right thing".
Good stuff! It's great to see LED bulbs about to make big inroads into the lighting market. As more and more are produced, economies of scale will kick in and they will become cheaper too. It'll only be a few years until the switch is complete, just like digital cameras replacing film ones and flat screens replacing CRTs. Woohoo!
Anne Ominous
BrianN: No. The mistake is there, but it's more egregious than what you thought. The numbers between these LEDs and CFLs. Even if you do it the (common but) wrong way, that still only gives a figure of about 66%. If you do the math, the LED bulbs use about 15% of the power that incandescents use. That leaves 85% (allowing for round off errors, etc. we can call that 84). So it's just plain mis-worded, and rather badly. This is due to a rather gross ambiguity of English when people try to describe "how much less", expressed as a percentage. They actually use less than 1/6 the power of incandescents, for the same amount of light. It would be valid to call that more than 600% as efficient. (Or 500% MORE efficient, since the incandescent is being used as the base of 100%.)
Tom Arr
When you took the two comparison shots for the bulbs lighting values, did you prevent the camera from adjusting for a different kind of light source, or did you lock it onto one value to keep the shots truly comparative?
Tom Arr
MBadgero, as I remember reading here on Gizmag I believe, the lifespan of early LEDs was reduced when the individual diodes were grouped too close together which resulted in the susceptibility to heat that LEDs suffer from, and now I think they are starting to space the diodes further apart to combat this.