http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/ Engadget Comments for Raleigh officials envision "world's first" LED lit city http://www.engadget.com/media/feedlogo.gif http://www.engadget.com en-us Copyright 2012 Weblogs, Inc. The contents of this feed are available for non-commercial use only. Blogsmith http://www.blogsmith.com/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 10:32AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 11:15AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
Hillsborough Street is indeed crater mile.]]>Feb 14th 2007 10:33AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 10:34AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 15th 2007 8:11AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 10:44AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
Yes, but they are not a viable alternative. The LED lights will likely last for at least a decade (assuming they are on 12 hours a day, and LEDs have a life of 50,000 hours). This far outweighs their high cost, as flourescents only last about 8,000 hours, plus the man-hours of changing all those bulbs has to cost quite a bit.

Besides the life, there are other problems with flourescents that people don't think about. The biggest one that I can think of of the top of my head is that they are a trigger to migraines in some people (my mother is one of them).

So yes, flourescents would technically be cheaper (at least initially), but they are not a better solution.]]>Feb 14th 2007 11:10AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
But hey... who needs improvements to real infrastructure, like mass transit to decongest that hellish traffic and improve air quality, when we have shiny new lights in our parking garages! Politics....it's a shady business...even when lit by LED ;)

...and BTW Glenwood needs a helluva lot more improvement than Hillsborough. ]]>Feb 14th 2007 12:05PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 11:24AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 11:31AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 12:46PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 11:36AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
i spent a lot of my childhood in Raleigh, it'll be interesting to go back there once they get this done . . .]]>Feb 14th 2007 11:42AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
http://www.wral.com/news/local/story/1201312/

Little-known fact about WRAL -- it's one of the few TV stations out there whose online video is viewable in the Wii web browser.
]]>Feb 14th 2007 11:51AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 12:10PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
Good work.

I am on the Raleigh Environmental Advisory Board. I can tell you that the city is working very hard to analyze and reduce its energy usage. This is one way to do it.

And it has the added benefit of proving LED's can work in these kinds of situations, which, yes, will help a significant local business.

Sounds like good government to me.]]>Feb 15th 2007 9:13PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Building and street lights are on ALL the time though (or at least all the time during night) so they will save money more quickly because they would normally burn through bulbs faster. Plus the cost of hiring someone with a bucket truck to go replace burnt out street lights will go down since LED lights need to be replaced a fraction of regular lights]]>Feb 14th 2007 12:11PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 12:18PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
Take traffic signals, for example...I doubt you will find a single new traffic signal that does not at the very least use LEDs for the red light. Many are now using them for the yellow and green lights as well. A number of existing lights have been retrofitted and the local transport authorities seem to love the fact that they aren't spending as much time changing bulbs any more.]]>Feb 14th 2007 12:36PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
Considering the price, there will be some people who would jump at the five finger discount. Or turn a tidy profit reselling them on eBay.]]>Feb 14th 2007 12:41PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 1:31PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
LED is nowhere near a mature technology yet. LEDs may look cool in your computer case and give a brighter light than those tiny incandescent flashlight bulbs, but trying to replace big gas discharge bulbs with LEDs is just insanity.

1. LEDs need LOTS of heatsinking. Their l/W output is terrible, and unlike an incandescent, halogen or gas discharge bulb, the heat can't be thrown out the front, it HAS to be heatsinked.

2. LEDs are tiny, tiny sources of light - they will cause lots of glare if not used with diffusers. Whereas gas discharge bulbs don't suffer with diffusers.

3. They're too expensive, and the fancy "More than 100 lumens per watt" are invariably tiny LEDs running at less than 1 watt.

4. The parking garage bulbs are not incandescent - they are already high-efficiency mercury vapor/metal halide or very high-efficiency high pressure sodium or ultra-high efficiency low pressure sodium.

So in conclusion, don't believe the hype.]]>Feb 14th 2007 3:42PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 1:55PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 2:28PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/Feb 14th 2007 4:40PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://en.wikipedia.org/wiki/Boathouse_Row]]>Feb 14th 2007 8:50PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
However when looking at applications such as street lighting, car parks etc., things look terribly different.

High power LEDs bring up the big problem of heat dissipation, usually the higher operating temperature also results in significantly shorter lifetime and lower efficiency. If these problems are going to be solved, the changes will take a number of years to make it to the mass market and become available.
Right now, even small, perfectly cooled lab samples do not reach hallmark efficiency compared to established technologies. And production units are even several years behind that.

High Intensity Discharge lamps in comparison have come a long way of optimization and today provide very high efficiency and colour quality, and they last well beyond 10000 hours. Their disadvantages (long startup time, not suitable for small spaces and low voltages) play no role in these fields of use.

I wonder if Raleigh has been stuck in the early last century or what they light their city with.
Unless they are using candles or incandescent bulbs, they are about to take a big step backwards.
I presume they are now using HID as pretty much every city on the planet does.
Switching to LED may well double their energy consumption while at the same time reducing colour quality, meaning a less comfortable, more straining light. So glad i am not paying my taxes in Raleigh ;)
But congratulations to CREE for the hype...]]>Feb 15th 2007 4:17AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
CFL go roughly 1/3 of incandescent...

LEDs go as low as 1/10 of incandescent...


But that's really really rough numbers, and depends on a lot of the supporting circuitry etc. to downconvert voltages, etc. There's little doubt you're at least halving the power you use with CFLs by switching to LEDs.]]>Feb 15th 2007 10:09AMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
I think evidence was presented that LED is not efficient for this type of application compared to other technologies, so I will impugn away. Questioning decisions made by those in seats of authority is citizens duty. I'm sorry if you were sitting on the Advisory Board and took other peoples biased facts and figures at face value. Maybe you should have done more of your own research (http://en.wikipedia.org/wiki/Light_bulb_%28disambiguation%29 is a good start...sodium vapor among others looks good ...no?) to present to the Board, rather than listening to presentations of what must have been some form of lobbying from Cree,Progress,and other interested parties.Instead of awarding contracts to change lighting systems to improve Raleigh's environment, maybe the "Board" should get focused on real issues facing the citizens and improve/build a mass transit for the Triangle. Too bad Cree doesn't make light rail systems huh?]]>Feb 15th 2007 1:28PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
I think it is fantastic that you decided to join the discussion. However, I am at a loss at how you missed the evidence I cited as to why LED’s are not the best technology today to use outdoor and public lighting, like your parking garage. Perhaps there is something in particular you disagree with that you’d like to share?

As it has been pointed out by me and others here, there are more efficient technologies that are more mature and more suitable for public lighting. You simply cannot drive even the latest LED’s from Cree (the current leader in LED efficiency) at near the same efficiencies and at their peak efficiency it’d require such low current per LED, that you’d need several hundred to equate the same light output as modern HID, HP Sodium, and especially LP Sodium lights.
Here is a chart that is fairly accurate. It’s a couple of years old, so a slight disadvantage to LED’s, but gets the point across:
http://www.lamptech.co.uk/Images/Illustrations/SO%20Lamp%20Efficacies.jpg

Here are the most recent numbers for luminous efficacy for some common lights in Lumens per Watt:

100w Tungsten – 17.5
Qtz Halogen – 24
Cree XRE @1000ma – 48
Cree XRE@700ma – 55
Cree XRE@350ma – 70
T5 Fluorescent – 104
Xeon Arc – 150
HP Sodium – 150
LP Sodium - 200 ]]>Feb 15th 2007 4:41PMhttp://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/http://www.engadget.com/2007/02/14/raleigh-officials-envision-worlds-first-led-lit-city/
--Jerry]]>Feb 17th 2007 6:06PM