Author Topic: City of Albuquerque to convert 19,000 street lights to LED  (Read 85 times)

abtempoecar

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City of Albuquerque to convert 19,000 street lights to LED
« on: December 30, 2017, 01:07:37 AM »
Those of you living in northern New Mexico (ABQ-Santa Fe-Taos) should be aware of this.I'm not sure if it's good or bad.
Any suggestions?http://krqe.com/2016...-lights-to-led/



helppomgido

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #1 on: December 31, 2017, 04:33:50 PM »
“Not only is it going to allow our city to be brighter and safer, it’s going to allow us to be better stewards of our environment,” Mayor Berry explained.

A substantially clueless statement.

If you're in Albuquerque, have the mayor visit this web site - International Dark Sky Association
http://darksky.org/l...ractical-guide/

<p class="citation">QuoteIDA Recommends
There are already many white LED options now available on the outdoor lighting market and that number will only rise in the future. IDA has developed a set of recommendations for those choosing lighting systems. These suggestions will aid in selecting lighting that is energy and cost efficient, yet ensures safety and security, helps reduce the impact of artificial light at night on wildlife, and promotes the goal of dark night skies.
These include:
• Always choose fully shielded fixtures that emit no light upward
• Use “warm-white” or filtered LEDs (CCT &lt; 3,000 K; S/P ratio &lt; 1.2) to minimize blue emission
• Look for products with adaptive controls like dimmers, timers, and motion sensors
• Consider dimming or turning off the lights during overnight hours
• Avoid the temptation to overlight because of the increased luminous efficiency of LEDs
• Only light the exact space and in the amount required for particular tasks[/quote]

Prasanna Patel

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #2 on: December 31, 2017, 05:37:57 PM »
White LED lamps are broadband, yes, but they may also be bright-lined. That is, the phosphors they use in front of the Violet-emitting LED are pretty much just three, R, G, and B, isn't that right? (I have not seen LED street-lamps, yet, however).

This can be studied even without a nice spectrograph, using a replica plastic film grating for viewing (or a prism oriented for dispersion, and not total internal-reflection).

Unfortunately, the broad-bandedness of the phosphors is not just discrete lines. And the breadths of the R, G, B phosphors overlap.

--Joe

Jeremy Kelley

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #3 on: December 31, 2017, 06:51:21 PM »
Quote
White LED lamps are broadband, yes, but they may also be bright-lined. That is, the phosphors they use in front of the Violet-emitting LED are pretty much just three, R, G, and B, isn't that right? (I have not seen LED street-lamps, yet, however).


Heres a quick effort with my trusty Edmund Scientific grating replica. The LED lamp looks pretty broad spectrum to me.... This is a household LED replacement light bulb. The bottom spectrum is a household CFL bulb -- basically the a mercury vapor spectrum with some broadening from phosphors. Lines in a true mercury spectrum are even narrower.

You can make filters to take advantage of the dark regions in the mercury spectrum (or similarly a low-pressure sodium spectrum), but there's not much you can do about the LED spectrum....

adpotabza

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #4 on: January 03, 2018, 08:03:53 AM »
ngc7319_20,

Great documentation and demonstration of species of home light-bulb spectra. Kudos!

The white LEDs in my laptop goose-neck keyboard-illuminator are not like that. The three phosphors have narrow outputs. I'll try to put up a spectrum here within a few days. One can hope that the street-light makers may put out lamps like my little LEDs' relatively discrete bandwidths, not like the lightbulbs' ones.

--Joe

Christopher Mendez

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #5 on: January 03, 2018, 06:13:40 PM »
I grabbed a camera and Edmund Sci grating and took a drive, and got some shots of local street lights.

The state just put in these LED lights at the freeway park-n-ride (bottom image) -- the spectrum is pretty much the same as the LED household light bulb -- mostly a continuum and will be hard to filter out.

The sodium light is one of these high-pressure jobs that are pretty common.  I couldn't find and low-pressure sodium lights tonight. Low pressure sodium is much more astronomy friendly as all the light is in one or two spectral lines.

The mercury light is one of these "cobra head" style street lights you see everywhere. Most of the light is in a handful of lines, so there is some hope to filter it out. I'm just guessing, but if the Albuquerque lights are like the ones around here, they will mostly be replacing dim and dead mercury lights with the LEDs.

David Allen

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #6 on: January 04, 2018, 03:00:52 AM »
Great forensic work. Kudos!, again.

--Joe

Joe Maillet

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #7 on: January 04, 2018, 04:20:46 PM »
It'll go to the company with the most kickback...if not, the absolute cheapest.....Lived in ABQ...Nice state, terribly governed....and it doesn't matter which party...PNM runs that state, and they will make the decision, the govt will just go along...

Jose Lukeson

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #8 on: January 10, 2018, 02:50:45 AM »
Raleigh, NC is rapidly converting over to LED streetlights, and the streetlights in my neighborhood were switched over in early February, including one on the property line with my neighbor to the east.

1) The light from LED streetlights is indeed nominally directed straight downward from near-perfectly horizontal fixtures. Vanishingly little direct light from them goes skyward (good)

2) HOWEVER, they are much brighter than the sodium-vapor fixtures they replaced - blindingly so if you look directly at them.

3) DESPITE the greater directionality of the light, the glaringly bright LEDs are visible from a considerable distance laterally out from the fixture - they are MUCH MUCH more intrusive into people's yards who live adjacent to a fixture.

4) Because the LED's are so MUCH brighter than the lights they replaced, they also reflect a considerably greater amount of light off ground or pavement into the sky, partly offsetting their advantage in directionality and near-perfectly horizontal orientation. Once a nearby city converts to LED streetlights, it probably is a net sky benefit to folks living several miles outside the city, and perhaps even within the city, provided you can view from a location not affected by the lateral light spill from an LED streetlight (see item #3 above).

5) If your yard is within the collateral reach of an LED streetlight (see item #3 above) - trust me, the full-spectrum nature of it is a secondary problem to finding a spot where you're shielded by e.g. shrubbery from direct view of the light - for deep-sky astronomy, you are actually worse off than before the conversion, even aside from the full-spectrum nature of the light.

6) SHIELDING: Unlike the old cobra-headed sodium fixtures, where a bit of paint or tinfoil inside the fixture lens could go a long way toward mitigating unwanted light trespass from a streetlight, I can see no readily available means built into LED fixtures to install any sort of directional shielding. Maybe something like that exists (??), but it's not something a utility crew can MAcGyver our of readily available materials.

engoecircming

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #9 on: January 10, 2018, 05:18:15 AM »
Quote
Raleigh, NC is rapidly converting over to LED streetlights, and the streetlights in my neighborhood were switched over in early February, including one on the property line with my neighbor to the east.

1) The light from LED streetlights is indeed nominally directed straight downward from near-perfectly horizontal fixtures. Vanishingly little direct light from them goes skyward (good)

2) HOWEVER, they are much brighter than the sodium-vapor fixtures they replaced - blindingly so if you look directly at them.

3) DESPITE the greater directionality of the light, the glaringly bright LEDs are visible from a considerable distance laterally out from the fixture - they are MUCH MUCH more intrusive into people's yards who live adjacent to a fixture.

4) Because the LED's are so MUCH brighter than the lights they replaced, they also reflect a considerably greater amount of light into the sky, partly offsetting their advantage in directionality and near-perfectly horizontal orientation. Once a nearby city converts to LED streetlights, it probably is a net sky benefit to folks living several miles outside the city, and perhaps even within the city, provided you can view from a location not affected by the lateral light spill from an LED streetlight (see item #3 above).

5) If your yard is within the collateral reach of an LED streetlight (see item #3 above) - trust me, the full-spectrum nature of it is a secondary problem to finding a spot where you're shielded by e.g. shrubbery from direct view of the light - for deep-sky astronomy, you are actually worse off than before the conversion, even aside from the full-spectrum nature of the light.

6) SHIELDING: Unlike the old cobra-headed sodium fixtures, where a bit of paint of tinfoil inside the fixture lens could go a long way toward mitigating unwanted light trespass from a streetlight, I can see no readily available means built into LED fixtures to install any sort of directional shielding. Maybe something like that exists (??), but it's not something a utility crew can MAcGyver our of readily available materials.


Lots of good points there.

The LEDs have much more blue light than Sodium lights, so will be worse for night vision, if you happen to have direct or semi-direct view of them. That's in addition to being brighter.

I'm not sure how the LEDs being brighter vs. more directional will play out. If they are shining on blacktop then maybe its a net improvement for distant astronomers since more directional. But shining on a grey concrete or snow or sand -- probably its just worse since brighter.

Will be interesting to see what solutions arise when people start to complain about the light trespass from LED street lighting.

inovcomsett

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #10 on: January 10, 2018, 05:23:05 AM »
Recently, an organization has been formed in New Mexico, to address light pollution issues specific to our state:Dark Sky NM
The web site is: http://www.darkskynm.org/

They can also be contacted by email at:[email protected]- Roy

inlaylale

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #11 on: January 10, 2018, 06:15:18 AM »
I’ve been able to research this issue a little more (one of the benefits of retirement) and I’ve found three non-astronomical reasons against light pollution:

1. Sleep deprivation.

2. Interruption of circadian rhythms in plants and animals. (Their systems don’t know if it’s night, day, winter or summer).

3. Bright, blinding lights don’t deter crime. House-invaders and other nocturnal criminals have figured out they can hide behind the glare and very dark shadows produced by LEDs.

These are also emotional issues which connect with the average citizen, as opposed to just us astronomers.
- Roy (again)

afelfillia

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #12 on: January 10, 2018, 07:40:50 PM »
Quote
Recently, an organization has been formed in New Mexico, to address light pollution issues specific to our state:Dark Sky NM
The web site is: http://www.darkskynm.org/

They can also be contacted by email at:[email protected]- Roy


Great link! Thanks!

belohalcu

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #13 on: January 11, 2018, 06:22:45 AM »
I went through this process with my town, and a couple of neighboring cities. We were at least successful in getting them to go with 3000 K LEDs, whereas they had been considering 4000 K LEDs previously. Best is to filter out the blue-component. You may find my slides to be of use. Feel free to amend as needed. Many of the slides have detailed notes with reference material to back them up.

https://drive.google...iew?usp=sharing

~Gary

Rahul Sanders

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Re: City of Albuquerque to convert 19,000 street lights to LED
« Reply #14 on: January 11, 2018, 11:14:29 AM »
Quote
Lived in ABQ...Nice state, terribly governed....and it doesn't matter which party...PNM runs that state, and they will make the decision, the govt will just go along...


Unfortunate but true. An unholy alliance exists between the state, cities, and PNM. And the latter pretty much calls the tune. NM's "grid" (fwiw) is small and isolated. Somebody has to buy PNM's overnight power generation. That is basically what it comes down to. Good luck finding out details of their relationship.