Better Streetlights for Tulsa

[patric]

It looks like GE is finally offering 3000 kelvin versions of their Evolve cobrahead series. It really wasn't up until recent their best offering was 4000k.

http://www.gelighting.com/LightingWeb/na/solutions/outdoor-lighting/street-roadway/evolve-led-streetlight-erl1.jsp

A 3000K maximum is a good compromise for city streetlighting, since it is "whiter" than the sodium lights we've been using the past 40-ish years, but if I were private sector or lighting an upscale subdivision, Id be salivating over the warmer looks of the 2000K - 27000K offerings. 

Frankly, it would be a crime against nature to be using anything bluer than 3000K at The Gathering Place or near the river in general.

[Cetary]

I agree, but I also think that communities looking to revitilize historic commercial districts of downtowns or even historical parts of town would also benefit from an extra low CCT about in that neighborhood. Even 4000 kelvin colored light looks cold and uninviting when used en-masse, not a good thing for attracting those friendly eyes.

[patric]

From behind the curve:



TULSA, Okla. (KTUL) – At a time when all Oklahoma governments are facing tough financial times, the City of Tulsa is taking steps to save on the city's lighting bill.

Efforts are underway right now to convert one-third of the city's downtown street lights to LED bulbs.
The idea was tested in a small park at Archer and Main and the result showed huge savings.

Thomas Baker of the Tulsa Downtown Coordinating Council said it can make our tax dollars go further.
"Right now the pedestrian lighting, which is predominately the acorn lighting in downtown, costs about $50,000 a year, and we can drop that by 60 percent by converting to LED," said Baker.

City Traffic Engineer Kurt Kraft says they are using LED lights on all new highway construction.
In addition to saving on electricity, there should be less demand for manpower when compared to traditional bulbs.
"The lamps for LED should last about 2 1/2 times as long as the high-pressure sodiums, so there's less maintenance just changing them out," said Kraft.
Work on converting more downtown lights should begin in the not-too-distant future.

Baker said they're simply trying to select the best possible conversion kit so when the LED lights are installed they will be as maintenance-free as possible.

In some cities, people have complained about the light emitted by LED bulbs because it has a blue tint.

Baker said they've asked people in the test area and no one noticed any change.



Ahem (cough, cough) welcome to TulsaNow.

Not all LEDs have a blue tint.  Maybe if you got the ones that dont, we wouldn't be repeating other city's mistakes.  But the warmer-color LEDs are a few lumens less you say.  Not as much as before, and the blue ones are much much brighter than the "adequate" Sodium lights they replaced so it isnt really a significant loss.  Certainly not significant enough to turn Tulsa's streets and parks into a pale blue mausoleum at night just to pick up a few extra lumens-per-watt.

Color is just as important as intensity and placement in determining perceptions of safety and attractiveness.  ...and the American Medical Association says there is a public health component, as well.  https://www.washingtonpost.com/national/health-science/some-cities-are-taking-another-look-at-led-lighting-after-ama-warning/2016/09/21/98779568-7c3d-11e6-bd86-b7bbd53d2b5d_story.html

We should get together and talk over lunch.  What's your favorite Taco Truck?
(Ive been looking for an excuse to make it to The Park In The Pearl since last weekends Eat Street event)

So you want to convert the Acorns?

So do I.  What a great opportunity to do something cool if we do some digging first.  First, the color.  Lets make them the same color that they were in the 1920s.  You can do that with LEDs.

LEDs with a color temperature of 2700 Kelvin are indistinguishable from the incandescent streetlights of yore.
That should be an easy choice to make.

The second part is harder... matching the intensity and ambiance of early Acorn streetlights is going to mean we cant use the Acorns as the sole source of lighting.  You should be able to look directly at an Acorn light at night without discomfort, because the higher-intensity lighting (doing the actual job of street lighting) should be done by color-matched, shielded (low glare) fixtures mounted much higher.

[AquaMan]

I wish you much luck with your effort to educate the city about lighting. I would suggest however that you repress any ego and reinforce the concept that this was their idea in the first place.

[patric]

I wish you much luck with your effort to educate the city about lighting. I would suggest however that you repress any ego and reinforce the concept that this was their idea in the first place.

It may very well be they have a completely different approach that has the potential to end up at the same destination.  Works for me :-)

Id love to see their ideas.

[patric]

Glare pours onto the street from a gas station and other commercial businesses where a pedestrian was killed, but the blame is anecdotally placed on a streetlight being out.  This is a good example of how poorly people understand how dangerous disabling glare can be. 

http://www.fox23.com/news/pedestrian-killed-crossing-the-street-near-21st-and-sheridan/458542006

[Cetary]

It looks like PC Amber LED streetlights are more then just lighting company lip service at this point.

http://www.ignialight.com/pimages/578280200-jpg-4EA/content/projects/29/iluminacion-led-vial-santa-pau-ignialight-copia-jpg.jpg

http://www.ignialight.com/pimages/578280200-jpg-2EF/content/projects/81/iluminacion-ambre-led-ignialight-2-jpg.jpg

[patric]

It looks like PC Amber LED streetlights are more then just lighting company lip service at this point.

http://ricemm.org/wp-content/uploads/2014/03/PNMM_St-Ludger_RBoucher.jpg

Interesting.  The High-Pressure Sodium streetlight at the end of the block looks slightly pinkish next to the amber LEDs.  Most people dont know HPS has blue and green spectra because the red/yellow is so dominant.

I like how the photo illustrates shielded lighting in the two streetlights just before the end of the block.  Those would be classified as "Full-Cutoff" (FCO).
If Tulsa had shielded streetlighting it would go a long way to improving night vision and safety by reducing glare.

For practical reasons, I wouldnt push amber LEDs everywhere, though.   Residential areas, agricultural areas, zoos and wildlife areas sure, but entertainment and business districts I would go with 3000K max.  Thats "white light" for us bipeds.

[Cetary]

If memory serves that blue spike comes from the mercury light within the sodium arc, and it's that mercury within the lamp that helps give HPS a higher CRI then monochrome low pressure sodium. There's also a variant of regular HPS, White SON, which is very much white light. White SON has an excellent 2700 kelvin CCT and a very adequate CRI of around 80. I think they use SON lamps in Britain. It might explain the lights on this bridge. They look like warm white lights. The sheilding on the fixtures is quite poor.

http://cdn1.share.slickpic.com/u/LondonHikes/NightLondon/org/IMG_2937/web.jpg

These are a bit better. I'm pretty certain they're SON lamps, or they could probably be ceramic metal halide. The color of the light is very reassuring. The color looks very nice, not like the ghastly blue gray palor of Los Angeles's 6th Street Bridge refit.

http://media.gettyimages.com/videos/time-lapse-of-traffic-on-london-bridge-and-the-shard-at-night-video-id477776300?s=640x640

An added bonus, here's some smaller scale warm white metal halides from GE.



http://www.gelighting.com/LightingWeb/emea/projects/olympic-park.jsp

Side note, there are actually three amber LED lights whose sources are not visable before the end of the block.

[Cetary]

Just found some more warm white LED streetlights. These are very warm 2700 kelvin lamps. About the lowest I've seen yet in the warm white department. Meanwhile they're in the process of installing the garish 4000k lights from Phillips where I live. Why can't we have these nice lights? I just shake my head and wonder why in the world 4000k is becoming so widespread. I'll see if I can get these posted without the links.

http://www.lighting-gallery.net/gallery/displayimage.php?album=2558&pos=12&pid=102005

http://www.lighting-gallery.net/gallery/displayimage.php?album=2558&pos=17&pid=98740

http://www.lighting-gallery.net/gallery/displayimage.php?album=2558&pos=18&pid=98721

http://www.lighting-gallery.net/gallery/displayimage.php?album=2558&pos=19&pid=98714

[Cetary]

Looks like Phoenix is going 2700k with its LED refit, impressive for such a large city. I really look forward to seeing the before and after shots, mostly the after shots though.

http://www.azfamily.com/story/33850377/phoenix-to-replace-all-90k-streetlights-with-leds

https://www.phoenix.gov/news/mayor/1575

"Mayor Greg Stanton and the Phoenix City Council voted unanimously Wednesday to move forward with a citywide effort to replace all of the city's street lights with energy-efficient LEDs.  

The Council approved a $30 million plan to convert approximately 100,000 street lights to LED over the next two years – which will save the city a net total of approximately $22 million through 2030 in reduced energy and maintenance costs.

"Modernizing our street lights is one of the many ways we're making Phoenix a more sustainable city, and doing our part to combat climate change," said Stanton. "The fact that we're saving millions of taxpayer dollars also shows how becoming more sustainable and more efficient is simply good business."

The Council also revised the city's standard color temperature (kelvin level) for street lights from the current 4,000 kelvin to 2,700 kelvin, which is considered a "warmer" color temperature for LED lights. The revision in the standard color temperature (kelvin level) for street lights was based on American Medical Association guidelines and extensive community input, potential environmental issues, technical lighting standards, and projected energy savings."

Looks like we really can do this.

[patric]

The Council also revised the city's standard color temperature (kelvin level) for street lights from the current 4,000 kelvin to 2,700 kelvin, which is considered a "warmer" color temperature for LED lights. The revision in the standard color temperature (kelvin level) for street lights was based on American Medical Association guidelines and extensive community input, potential environmental issues, technical lighting standards, and projected energy savings."

I was able to get at "3000K or less" provision in the now defunct Form Based Code, but when the City revamped the zoning code for 2016 it was not among the suggestions I submitted that were approved.  At least we got some shielding requirements in to cut back on the glare.

I saw warm-white LED 2700K cobra-head streetlights all over St. Louis my last visit there.  Maybe we need a city council road trip.

[Cetary]

Looks like PC Amber LEDs are gaining ground in Florida. While the main reasoning for the primary beneficiaries of these new lights are sea turtles, they still directly benefit people as these lights have little to no blue content thereby protecting circadian rhythms. I believe that PC Amber light should really be looked into more.



http://www.gulfpowernews.com/turtle-friendly-led-lights-installed-for-nesting-season/

Extra bonus, some more PC Amber LED street lights. Patric, I believe you wanted some dusk shots of some PC Amber lights? For those that aren't familiar with Phosphor Converted Amber LEDs note the very high operating power, 100 watts to a fixture. Regular old amber LED technology wouldn't be viable at that power as the LEDs would end up overheating with their light output falling sharply without heavy cooling. PC Amber LEDs use that traditional blue LED just like white LEDs, but the phosphor coating is so heavy it converts all blue light into longer wavelength yellow, orange, and red light. This helps to explain why PC Amber LEDs have a much smoother spectral output then HPS and partly why their CRI is significantly higher.










Link to more PC Amber LED shots.

http://www.pnj.com/story/news/local/environment/2015/01/29/turtle-friendly-lights/22544943/

[Cetary]

Found this interesting webpage on the inner workings of a modern warm white LED cobra head. Has some interesting looking close-ups.

http://www.streetlightonline.co.uk/MiniIridium_photographs.htm

[patric]

Found this interesting webpage on the inner workings of a modern warm white LED cobra head. Has some interesting looking close-ups.

http://www.streetlightonline.co.uk/MiniIridium_photographs.htm

Thanks,

In case you missed it, another member here discovered one of the poorest installations of LED lighting I have ever seen

http://www.tulsanow.org/forum/index.php?topic=18723.msg314002#msg314002

On the road next to the Arkansas River.  Blue-rich Environmentally-unfriendly high Color Temperature, waaaaay over-lit, and really serving no real purpose for that amount of light (except to keep the electric bill the same?)