LED breakthroughs

Here's a little excerpt from an article running today on EcoGeek:

"Using a nano-crystaline coating, scientists at Bilkent University in Ankara, Turkey have created an LED that produces attractive white light while wasting next-to-no electricity . For every watt of light produced, about 300 lumens are visible to the human eye. Fluorescents produce about 80 lumens per watt, and other white LEDs are closer to 60. 300 lumens per watt is two times more visible light per watt of radiation than I've ever heard of for any light source, and they've done it with natural-looking light."

Read the rest of the article here.

I was sort of bummed to read:

The nano-crystalline coating is very expensive and difficult to produce, and, so far, there aren't a lot of ideas as to how to mass produce these things.

But still, that's good news. I'm still looking for a good, energy efficient  lighting source that produces fairly white  (or at least natural) light.

300 lumens per watt seems a bit high given that most sources I've seen say that for white light, 242.5 lumens is the most possible.  Now if you restrict the frequency of the light to that which human eyes are most sensitive (yellowish-green), 683 lumens per watt is apparently possible.

A quick search revealed this one source that corroborates the above numbers: http://members.misty.com/don/bulb1.html

For now I am waiting for the C. Crane GeoBulb, due out later this month, that produces 800 lumens from less than 8 watts, the first LED lamp I've seen that exceeds 100 lumens/watt.

Wow, I'll be really interested in hearing your thoughts after you get your GeoBulb!

Hopefully I'll be able to report my findings here in a couple of weeks when I get my hands on one or two of them.

Sounds great!  We'll be eagerly waiting.  :-)

I just checked the C. Crane website and the GeoBulb is now out of stock until 6/30, moved from 5/14.  So I'll be waiting another month and a half for this bulb to be available.

Oh bummer!  Well...bummer for the wait.  Great that C. Crane has had so much interest in the GeoBulb!

I just checked the C. Crane website again and was disappointed to see that the availability of the GeoBulb has slipped another month to 7/31.

I guess this is giving the competition a chance to catch up to them . . .

Anyone know what chip they are using? I know Cree has a chip in development that's around 300 lumens per watt.

Check my first post in this thread; as far as I can tell the upper limit for the efficacy of generating white light from electricity is 242 lumens/watt, I've seen that number claimed in various sources.  If you have information to the contrary I'd love to read about it.

As far as what emitters are being used in the GeoBulb, that I do not know.

Apparently that 242 lumens/watt figure is for more full-spectrum white light as you would get from a theoretical black-body radiator; white LEDs usually produce so-called dichromatic white light (blue plus yellow typically) and I see now that there is more potential for high efficacy in that situation, at least according to this source:

http://members.misty.com/don/lfunfac2.html#ole

Maximum theoretical efficacy numbers approaching 500 lumens/watt are claimed near the bottom of that page.

Regarding the backorders - is there some type of production problem / delay, or is this really due to heavy order levels?

Here is the reply I got from C. Crane Customer Service when I asked about the slip from 5/14 to 6/30:

"Thank you for taking the time to contact our company.  The bulbs are in the process of being manufactured in small batches.  We are very confident about the date of June 30th however it is still tentative.

If you have additional questions or we can be of further assistance please email or call our toll free number."

and here is the reply about the slip from 6/30 to 7/31:

"We have missed our scheduled delivery date of the GeoBulb. We appreciate your patience and hope it has not caused unnecessary frustration.

We have made excellent progress in the last few weeks on the last few items to be resolved. UL and FCC listings should be complete in a few weeks and allow production to proceed. We hope backorders will be filled by 7/31/08 but it is possible it might extend a few weeks after that.

We will be posting additional information on our website as well as sending out an email to our customers with GeoBulb updates as soon as we receive them.  To sign up for the updates please sign up https://www.ccrane.com/ssl/subscribe.aspx

If we can be of further assistance please either email or give us a call."

So the problem would appear to be production-holdup related.

Ouch...that's a bit frustrating. Keep us posted for sure. Thanks Bob!

Sounds frustrating indeed.  ...I just saw red flags regarding production when it slipped as far as it did - as your specific order should never of pushed that far just for ordering levels as it would catch up to you sooner than that, with orders after you slipping. 

Hope you get the bulb(s) soon... can't wait to hear how they perform!

Actually I'm waiting until it says they are in stock before I place an order.  I suppose that might delay my getting one to some degree.  But I saw no indication that they would not charge me until it shipped, and I'd rather they didn't have my money while they slipped the availability by weeks at a time.

Well after further digging around on their website I now see that it does say that I will not be charged for backordered items until they ship:

http://www.ccrane.com/backorders2.aspx

But I have had problems in the past with companies disregarding their own policies and you usually have to push pretty hard to get the charges reversed in such a situation.  So for now anyway, I'll keep waiting for the GeoBulb to be in stock before I place an order.

Right up until yesterday the GeoBulb still had the 7/31 delivery date, now today I checked it and the date has slipped (for a third time) to 9/1.  I'm finding this situation difficult to understand.

Here is their reply to my contacting them about this latest slip:

Odd that you should write now, I was thinking of dropping you a line this morning.  We just received word yesterday evening that our latest samples in testing have passed FCC regulations.  As far as I know we are the first company to do so for a LED light bulb of our style. This should be our last big hurdle before mass production starts. We should have some completed units here near the end of August. Production quantities should follow soon after.  Keep up the faith, the future is here.

If you have additional questions or we can be of further assistance please email or call our toll free number.

I just checked again and the date has now slipped to 9/30.

You are a patient man, Bobkart... wow.

I recently ordered 2 CL-5 bulbs from EarthLED.  Will let you know how they are when I recieve them...