Better Streetlights for Tulsa

[patric]

How different sources of light compare, spectrally

INC - incandescent
CF - Compact Fluorescent
HPS - High Pressure Sodium (most streetlights now)
MH -Metal Halide
SUN - sunlight

[Red Arrow]

Not an overlay, but you can line up the wavelengths (nanometers)


And yes, the golden-colored High Pressure Sodium light is going to be better for the eye than Metal Halide or bluish-white LED's, given the research sofar.
The first chart shows the eye's Circadian sensitivity (that also governs the production of Melatonin) centered about 460nm, while Sodium streetlighting is around 600nm -- much closer to the eyes visual (Photopic) sensitivity than the bluer culprits.

It looks like the HPS makes a good portion of its light at longer wavelengths than human eye sensitivity. The Blue-rich LED looks like a good match, better than HPS, if the spike at about 460 nm could be filtered out. Might waste power though.  I won't argue the aesthetics of the color for street lights.  My dad used to (passed away years ago) complain about the HPS street lights.  He said the proponents touted the amount of light they put out compared to mercury vapor lights for an equivalent power consumption but they neglected to say that a significant portion was not effective for human vision.  

My main interest is for automobile headlights.  I started driving behind quartz-iodide headlights in the early 70s.  I liked the greater illumination they provided.  I don't know if it was the color, the greater lumens for the same power, the lens pattern, or a combination but they were far superior to the tungsten headlights of the time.  When I went on trips, I frequently drove at night on the Interstates and really appreciated not overdriving the headlights.  

Thanks for the chart.

I wrote this on the chart you first put up.  I'll have to look at your latest stuff in the AM.  I have to get up at 6:00.

[Red Arrow]

Patric

OK, I couldn't resist looking.   Would you please repost the first HPS chart and explain the difference between that and the one you now have posted.  I think most of those lights are color corrected somehow.  Maybe "they" have done some work on the final color. 

[patric]

It looks like the HPS makes a good portion of its light at longer wavelengths than human eye sensitivity. The Blue-rich LED looks like a good match, better than HPS, if the spike at about 460 nm could be filtered out. Might waste power though.  I won't argue the aesthetics of the color for street lights.  My dad used to (passed away years ago) complain about the HPS street lights.  He said the proponents touted the amount of light they put out compared to mercury vapor lights for an equivalent power consumption but they neglected to say that a significant portion was not effective for human vision.

Blue-rich light is only advantageous at low lighting levels where the eye is relying on Scotopic vision (think full moon).
At higher lighting levels (Photopic vision) the eye is more sensitive to yellow-green.
Ratcheting blue spectra up into Photopic vision levels (where the eye is more yellow sensitive) isnt helping human vision at all, and merely upsets our "body clock". 


Streetlighting falls within the descriptions of Mesopic (porch light, residential street light) to Photopic (brightly-lit city centers, gas stations, billboards) vision.

Also, think for a second why foglights are amber and not blue.
If blue light scatters 3-4 times more in atmospheric vapor than amber, a blue light would simply reflect back the fog, whereas the amber fog light would penetrate the fog and reflect back more useful information (like the road).  This is known as Rayleigh scatter (and is the reason the sky appears blue).
http://resodance.com/ali/bluskies.html

[PonderInc]

This may be something that Patric has covered in the past, but I didn't  bother to search for it...

I was told that the City of Tulsa pays a recurring flat fee to AEP-PSO for each streetlight in town...regardless of whether or not it's on (ie: burnt out bulbs, maintenance issues, etc) or how much electricity it uses.  (This doesn't include "decorative" acorn lights, etc.)  And that the Corporation Commission decides how much the City will pay for each.  Did I hear that right?

So PSO determines the type of fixture, bulb, etc...and the Corp Commission determines the cost per light...and the City doesn't have a say in it?  This makes no sense, so I hope it's false.  Can anyone verify or correct this info?

[patric]

I was told that the City of Tulsa pays a recurring flat fee to AEP-PSO for each streetlight in town...regardless of whether or not it's on (ie: burnt out bulbs, maintenance issues, etc) or how much electricity it uses.  (This doesn't include "decorative" acorn lights, etc.)  And that the Corporation Commission decides how much the City will pay for each.  Did I hear that right?

So PSO determines the type of fixture, bulb, etc...and the Corp Commission determines the cost per light...and the City doesn't have a say in it?  This makes no sense, so I hope it's false.  Can anyone verify or correct this info?

AEP-PSO submits Price Code Schedules to the Corporation Commission for approval as a part of contractual Franchise Agreements they make with municipalities.

The MSL (Municipal Street Lighting) price code gives monthly prices for different streetlights depending on wattages and what it is mounted on (traffic light pole vs. PSO-provided poles, etc).

In 1997 a 400-watt Sodium streetlight on a wooden pole (Price Code 0832-N) cost $7.82/month.  Being un-metered, the cost is levied whether the light is actually present and working or not.
In 2000 the Tulsa World's Phil Mulkins did a series on streetlighting under the "Action Line" column, where City Traffic Engineer Jon Eshelman explained the streetlight rates as an annual payment "less than $100 per residential light and more than $100 per arterial lights."

If a light were removed, the municipality would have to pay PSO an amount equal to the unused portion of the fixture's predicted life (usually around 15 years).

The Corporation Commission does decide the rates on the price code, but that actually consists of the CC rubberstamping the rates AEP-PSO submits to them.   

When I did a report for Mayor Lafortune's Performance Team in 2003, AEP had a difficult time documenting exactly how many lights of each type the city was paying for, saying they would have to hire a consultant to make such an inventory.  The situation was reminiscent of 1988 when the city auditor took PSO to task for double-charging for lights:
http://www.cityauditorphilwood.com/audits/StreetLight88-89-01.pdf

[patric]

So PSO determines the type of fixture, bulb, etc...and the Corp Commission determines the cost per light...and the City doesn't have a say in it?  This makes no sense, so I hope it's false.  Can anyone verify or correct this info?

...and to answer the second part of your question...
Ill cite a January 2000 TW "Action Line" article again:

' (lighting specialist Michael) Lemley explained that the ``farm light'' is part of Public Service Company of Oklahoma's standard and, therefore, part of the city of Tulsa's standard for replacing and erecting new street lights. Before the shielded reflector could be adopted as the city's ``standard street light'' -- as it is now in the cities of Texas and Oregon, Tulsa's City Council will have to adopt the standard and require PSO to change its streetlight standard.

``Having Renaissance involved in this is a good start,'' Lemley said. ``When they started working on this, I said: `It is one thing for you to individually try to do this, but there are two areas you have to go after -- one is the City Council, to convince them to review the current standard, and two is to get PSO to change its standard.''  '

So as I understand it, PSO gives Public Works a list of lights it wants to use, and they in turn "require" PSO to use those lights as part of the streetlight standard. 
One of the past requirements is that each fixture burn a minimum of 100 Watts of electricity, since PSO uses the  streetlights to "balance their load" during off-peak electrical consumption. 
Designing streetlighting for the wrong reasons is what leads cities to spend too much money on street lighting that doesnt do a good job of lighting streets.     
My last estimate was around $2 million/year Tulsa is wasting with it's present streetlighting strategy.

The course of action is still to get the city council to review it's streetlighting standard, and make visual performance a higher priority than the utility's need to sell off-peak power, but who in office has the courage to do that?

[patric]

AEP is doing some good things with streetlights in Eureka Springs, since there is now a state law requiring all new publicly funded outdoor lighting be shielded.  

AEP is already retrofitting most Eureka Springs street lights to 100w flat glass cobra-head lights or GE SkyGards, in anticipation of the unanimous passage of the city's new outdoor lighting ordinance;
http://cityofeurekasprings.org/ORDS/planords.html

If passed, the ordinance will require all new lighting over 100 watts incandescent or other light sources over 4,000 lumens to be shielded, even AEP lighting leased to residential and business customers.  

New horizontal floodlights will be prohibited and old ones that fail must be removed or replaced with a shielded light.

The Planning commission supports the ordinance unanimously.

[patric]

One of the exhibits for the new Eureka Springs ordinance (.pdf):

[patric]

Testing LED streetlights in Portland:

http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/gateway_lija-loop.pdf

The irony of this test is that the streetlights they are replacing are BETTER than what we currently use in Tulsa.
...another indication of how far behind the curve we are.

The appendix to this report also includes the city's written Streetlight Standards (something else we dont have in Tulsa).

And in Boston:
http://www.cityofboston.gov/environment/LED

[Inveree09]

Looks like good value to me, i would normally just share a starter and then have a main each. usually too full for dessert after the huge US portions. I dont know how anyone can contemplate having a starter each, a main and a dessert. may  be there is a difference between US citizens and the UK, dont want to generalise though.

[Hoss]

Looks like good value to me, i would normally just share a starter and then have a main each. usually too full for dessert after the huge US portions. I dont know how anyone can contemplate having a starter each, a main and a dessert. may  be there is a difference between US citizens and the UK, dont want to generalise though.

And, once more...

[patric]

Appears to be someone from the UK that is really, really lost...

[patric]

Simonson and Tulsa Mayor Dewey Bartlett think they've come up with a bright idea to turn the lights back on and save the city money. The city is applying for $750,000 in stimulus money to replace some current street lights with LED lights. If approved, the money would come from the Department of Energy and be part of the city's energy efficiency strategy.

http://www.newson6.com/Global/story.asp?S=11805839


But, they are soooooo blue....

[TheArtist]

 I honestly havent even noticed any difference with the lights off in the areas of I have been in.  There is so much ambient light from the rest of the city (all the QTs perhaps  )that you can see quite well.