LED Street lights - getting better

blasterman

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I noticed lately that a new style of LED street light was popping up in a local town, and these were quite a bit different than the ones I've seen deployed in other areas. It's also the first large scale roll-out I've seen of the LED fixtures used for several miles of roadway.

First thing I noticed about the new lights was the color. My camera balanced in RAW at about 4500k, and visually I'd put them aroudn there. You can see in the picture the oncoming halogen headlamps aren't an extreme difference in color showing how warm these lamps are. No cool-white 'blues' here. What's also interesting is each fixture only has 36 heads - Obviously I can't tell what brand of emitters are, but that is certainly the lowest number of discrete emitters I've seen in such a fixture. Pretty obvious were aren't dealing with under-driven XP-E's.

The only negative was oddly the color. Something was 'off' in regards to the color rendition, and I have a suspicion these LED's are the infamous 'ANSI' spec'd versions which sacrifice CRI for increased efficiency. I have all brands of neutral white emitters laying around and none are as 'flat' as these lamps were with the exception of a ANSI spec'd neutral white rebel.

These lights were used to replace mostly mercury vapor fixtures, and the corresponding intensity is very similiar, although they have a far more even spread. In that respect, somebody did their homework. I posted some shots awhile back of some much brighter fixtures used down-town for evaluation, and although much brighter the color was around 6500-7000k and far more annoying.

7037277679_0c55f6693e_c.jpg
 

idleprocess

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These lights were used to replace mostly mercury vapor fixtures, and the corresponding intensity is very similiar, although they have a far more even spread. In that respect, somebody did their homework.

Almost any "neutral" white LED on the market today from a quality manufacturer would be an improvement over the blue-green spectrum of mercury-vapor lamps.
 

blasterman

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Retrofits - West Michigan. I'm trying to find the exact heads being used.
 

blasterman

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Nope - not on the list. I took a close look at the lights in the daytime and they are unique interms of thermal management. There are two rows of 18 LEDs, and in between them is a rather finely spaced radiator grill. On top of the light there appears to be a cap, which likely protects the fins from debris, bird crap, etc., but still allows air to flow. Looks like somebody took vertical convection seriously. When I have a chance I'll take a picture and post them to that site.
 

Canuke

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Blasterman, do these LED streetlights have a resemblance to flip-flop shoes in daylight? The ones I'm seeing in several neighborhoods around Las Vegas (northwest area of town) look like that, and have very consistent 4500K look about them, almost no variance between examples. I'm 99% sure they are LED because of the spectral shape when checked using a CD.

These have the fins on top too. At some point I have to get some shots of them.
 

Canuke

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The orange sodiums just got swapped out in front of my house today, for what seems like blasterman's LED units. I'm in northwest Las Vegas. They appear to be swapping these out together with street repaving.

These are not the same units as the sandal-looking things I mentioned earlier; those are in a different subdivision nearby, and have a concentrated spot source within which I cannot discern individual emitters.

The new ones are wider and have what looks like 2 rows of discrete emitters. The newer units are also a bit warmer/yellower in color than the "sandals".

I'm going to try and get some daylight pics of these tomorrow.
 

PhotonWrangler

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A month ago I saw some LED parking lot lights show up in my area, and in the last two weeks I noticed a couple of LED streetlights along the freeway near a rest stop. They appear to be test units as there are only two or three of them. I haven't gotten a close look at them yet but they seem ok-ish in terms of brightness.
 

Canuke

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Finally, here are my shots of the "sandal" LED street lights going in around my neighborhood. Only now do I notice that they are helpfully labelled "LED" :)

The wider unit is the one right outside my front door; the longer and narrower units are older by about a year, and are in a neighboring subdivision. Both are definitely using Crees, as you can see from the detail crops; they appear to be XP-E's in the older units, and XP-G's in the newer ones to me. Color temps are cooler in the older units, and seem a bit more appealing to my eye than the new ones.

The new units look like they have 18 emitters in a spread out pattern (except for 2 pairs of 3 off to one side, not sure what's up there), whereas the older ones have 27 in two tight rows.
 
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idleprocess

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The "Sandal" lights are apparently trying to mimic the footprint of standard "cobra" heads for MH/sodium-vapor streetlights.
 
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