Evolution of the San Jose light pollution throughout the night

[Julien Lecomte]

Folks,

I am sorely disappointed.

In 2010, I participated in a demo of the soon-to-be-deployed LED streetlights as well as a public meeting on the same topic shortly after that. One of the talking points that the consultants paid by the city of San Jose kept going back to, probably to appease the most environmentally conscious among us, was that LED technology would allow the city to dim the streetlights after midnight, or even after 11pm in some areas with little vehicular or pedestrian traffic, or dynamically, in real time, based on street usage, using motion sensors. While that is technically possible, I now have the proof that nothing of that sort has ever been implemented. How was I able to prove it? Well, certainly not by asking! I did ask, and received the silent treatment from my council member (whom I won't be voting for the next time around) and from the Director of the department of transportation. The next step could have been to proceed with a formal request for official city records (Federal Freedom of Information Act) Without going to that extreme (especially since that would have yielded thousands of documents for me to comb through, and I don't have that kind of time), I decided to dust off my spectrograph and created an animation of the spectrum of my local light pollution. Here is the result (animated gif):

(the timestamp at upper left is in local time)

Some things change throughout the night, like for example the emission lines caused by airglow. That is expected. Unfortunately, the broad spectrum produced by LED streetlights does not change at all in its intensity throughout the night.

Before the end of this year, I would like to put together a file, with indisputable data, that shows that the city can do more to protect the environment, but also to save taxpayers like me (and you, if you reside in San Jose) some money, because even though LEDs are very efficient, it still takes a lot of energy to power all those lights.

- Julien

[John Pierce]

FWIW, the street light outside my driveway does seem to autodim late at night when theres no traffic.   car comes by and it gets 2 or 3 times brighter for several minutes.

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[Akarsh Simha]

Why do cars need streetlights when they have insanely bright LEDs themselves?

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[Jeff Crilly]

FWIW… we now have an LED street light.  The previous non-LED burned out and it was dark for months and months.    Then they fixed it by replacing it with a whole new LED based housing etc.   Our house blocks most of the light trespass attempting to get in the backyard, but there is a swath that hits the back fence bushes.   There’s no cutoff shield on this streetlight so the LED light shines like 180 degrees.  

And it is “on” 24 hours x 7 days a week.   Yep the sensor to turn it off during the day is busted.  

Sent from my iPhone

On Jul 22, 2023, at 1:28 PM, John Pierce <jhn.p...@gmail.com> wrote:



FWIW, the street light outside my driveway does seem to autodim late at night when theres no traffic.   car comes by and it gets 2 or 3 times brighter for several minutes.

On Sat, Jul 22, 2023 at 1:23 PM Julien Lecomte <julien....@gmail.com> wrote:

Folks,

I am sorely disappointed.

In 2010, I participated in a demo of the soon-to-be-deployed LED streetlights as well as a public meeting on the same topic shortly after that. One of the talking points that the consultants paid by the city of San Jose kept going back to, probably to appease the most environmentally conscious among us, was that LED technology would allow the city to dim the streetlights after midnight, or even after 11pm in some areas with little vehicular or pedestrian traffic, or dynamically, in real time, based on street usage, using motion sensors. While that is technically possible, I now have the proof that nothing of that sort has ever been implemented. How was I able to prove it? Well, certainly not by asking! I did ask, and received the silent treatment from my council member (whom I won't be voting for the next time around) and from the Director of the department of transportation. The next step could have been to proceed with a formal request for official city records (Federal Freedom of Information Act) Without going to that extreme (especially since that would have yielded thousands of documents for me to comb through, and I don't have that kind of time), I decided to dust off my spectrograph and created an animation of the spectrum of my local light pollution. Here is the result (animated gif):

<light-pollution-animation.gif>

(the timestamp at upper left is in local time)

Some things change throughout the night, like for example the emission lines caused by airglow. That is expected. Unfortunately, the broad spectrum produced by LED streetlights does not change at all in its intensity throughout the night.

Before the end of this year, I would like to put together a file, with indisputable data, that shows that the city can do more to protect the environment, but also to save taxpayers like me (and you, if you reside in San Jose) some money, because even though LEDs are very efficient, it still takes a lot of energy to power all those lights.

- Julien

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[Ted Hauter]

Some words of encouragement.

And some reality humor (kind of).

In the bay area the San Mateo club got a light shielded that shines into Crestview park from across the street (Nice park! Little parking, strange curbs where people trip and fall constantly, but very nice and no direct lights! Awe droppingly, there is Milky Way SE on a perfect night in a Bortle 8). Without that shield, the park would be useless. The light to the ramped parking lot is eye level.

There should be a plaque made for all Astro, a yearly honor, to the most tenacious individual making a difference, of that light shield. In bronze.

Next is a story of how the city folk works. I am not one of them but basically the same in maintenance engineering. So I look like one of them but am not one of them kind of like Superman.

So I go to the park (different park) with my 8 year old son and he disappointingly points out some graffiti. This stuff has to be remedied asap. We find more on our walk. I call the city and get a real person and tell them the locations. 

Two retired workers still working show up about five days later and take pics of a park bench and have a bucket of paint. They spend about 20 minutes over there and more pics and mess with a garbage can. One paints with a dripping roller the top of one picnic table and I'm really pleased. They are going to do all these tables and they need it. 

We play for a few minutes and I look up and see them get into the truck and drive away.

At least thick paint still dries quick when it's 85 out.

Someone did come back and did remove what we called about. Patience. 

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[KG]

Some one in Caltrans’s palms are greased by the vendors supplying the poles and bulbs- I am serious, no joke. G

Sent from my iPhone -made in China😴

On Jul 22, 2023, at 3:13 PM, Ted Hauter <thgo...@gmail.com> wrote:



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[Vishal Kasliwal]

Hey Julien,

      That's an extremely commendable effort. Not only would auto-dimming lights reduce light pollution locally in San Jose and the rest of the Bay, but they'd also reduce light-domes at nearby dark sites. 

Out of curiosity, what's the annual electric bill per resident for street-lighting?

Best,

Vishal

[Rajah]

I have a corn or house with 3 super bright LED street lights, 6 months ago one of them died and it was the best thing for my backyard imaging and observing, however, they fixed it last week and it’s bright in my back yard again 🙄

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[Vishal Kasliwal]

Isn't there a way of comparing about excess light intruding into one's house, causing issues with one's cyridian cycle?

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[Julien Lecomte]

Guys, you should complain and ask that the city you live in shields the offending fixture. With some assertive politeness, you should be able to get them to do it. Otherwise, you can always threaten to sue… But don’t let them illuminate your house for no good reason, that’s flat out ridiculous!

- Julien

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[mccart...@yahoo.com]

Hi Julian,

I found the SJ streetlighting plan here, it says they "may" be dimmed, but not that they "shall."  So perhaps no directive was put in place by the city?  So more teeth in the policy is needed?

While I'd never discourage complaints from individuals and using one's vote, a wider audience is needed than just TAC.  Your data and perspective would make a great news story.  Remember Jeff Crilly was on KPIX5 for the M101 Supernova?  Maybe contact Brian Hackney (who is apparently very interested in astronomy) to tell your story.  Ask KPIX reporters to talk to your supervisor & the city manager, and to research why SJ's lighting has not been dimmed.  It would put "the spotlight" on them.  It would seem they sold the public a bill of goods re: LED dimming, and more attention needs to be brought to bear.

It would be great if we, TAC, could collect more data from other cities around the Bay Area.  I suspect the same situation exists.  I don't image but perhaps those who do (with Julien's guidance/assistance) could collect more data to bring more attention.

Mark

[Julien Lecomte]

Thanks, Mark.

I will first attempt a more gentle approach, which likely will take time, but it is the right thing to do. Only if that does not go anywhere would I ever consider contacting the media.

You are correct that the streetlight plan was worded in such a way that allowed the city to sell us a vision without having to actually implement it. It is regrettable, but all hope is not lost. The hard (and expensive) part was to deploy the LED fixtures. Controlling them may not be that difficult.

- Julien

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[Vishal Kasliwal]

I'm committed to idea enough that I want to help. I'll volunteer to help. I don't have anyone in my  network with ties to the city, so someone else (Julian?) has to take the lead...

Vishal

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[Peter Natscher]

Since the availability of LED outdoor lighting, residents have been adding this lighting to their backyards for evening entertainment.  LED's use so much less electricity than past incandescent lighting, residents are powering on their outdoor LED lighting more.  My neighbor has LED deck lighting on a timer and it lights up every night for a few hours after dark so the backyard can be seen from inside the house.  Cheap electicity or not, it's wasteful thinking.

[Vishal Kasliwal]

I hate the trend, but it's impossible to reverse.

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[John Pierce]

On Sun, Jul 23, 2023 at 3:19 PM Vishal Kasliwal <vishal....@gmail.com> wrote:

I hate the trend, but it's impossible to reverse.

indeed.   and we 'dark enthusiasts' have to be careful we're not seen as cranks like the anti-wifi and anti-cellular crowd. 

[Julien Lecomte]

John is right.

My neighbors have bright LED lights in their front yard and backyard. As long as they are on timers and/or motion sensors, I'm ok with it. It's just a matter of being reasonable.

- Julien

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[Peter Santangeli]

Indeed. And some of the anti-light-pollution rationale I've seen in the past really doesn't pass the 'smell test' for most people.

Example: I've seen it claimed that "Because criminals need light too, they are more likely to break in when it's well lit. So lights are bad." being used in (otherwise serious) anti-light-pollution info. Whether true or not, that's never going to hold water with the general public, who just want to be able to SEE criminals.  That is 'crank-worthy' rationale.

Appealing to (1) the beauty of the sky, and (2) energy efficiency, seems to be the most effective thing. Unfortunately, it's just a fact that the progress of lighting technology has made point #2 weaker, or at least harder to use.

pete

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[Julien Lecomte]

Who needs to see criminals when people are sleeping? :)

We all need to be reasonable. In my lower-class neighborhood, exactly 100% of the people don’t give a rats ass about the night sky or the environment. They simply don’t, end of story. It doesn’t make them bad people. What they care about is not getting their car windows smashed at night, that’s about it. And they feel like inundating the neighborhood with light will convince criminals to go elsewhere. It’s clearly not super effective, but the psychology is strong. So, I stopped asking my neighbors to turn their lights off, and instead bought them a motion sensor, or a fixture that at least sends all the light towards the ground. They are perfectly okay with that, and once I’ve told them that I take photos of the night sky from my backyard and this small change will help me, they feel even better about it.

Gentle common sense works. Telling people you know better than the way they feel doesn’t. No need to even try…

- Julien

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[Stephen Migol]

Julien,

I also live in a working neighborhood and have worked with my neighbors to shield or point their lights downwards.   It usually works well.  It helps to bribe with veggies from the garden.

I also had the displeasure of having to call attention to a nearby school that had replaced their parking lot lights from unshielded sodium vapor to unshielded LED.  While my windows did not face the building, the glare through the trees was enough to be annoying.  A few pictures, a note showing the county ordinances about light trespass, and within a few weeks they had a crew up on a scissor lift to shield the lights.

I also like to tell people about the owls in the area and how these keep the vermin at bay.  

On another note, does anyone have details on a counter for the cheapo street lights that have burned through their phosphor and are bathing the streets in UV?  There are two intersections near my place that have broken this way.  From what I have read, this is a problem of poor mfg.  

Stephen

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[Nikola Nikolov]

Dimming is possible with Matrix LEDs.  These are available for both street lights and car headlights. 

I am not sure, if San Jose street lights are Matrix LEDs.

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[Francesco Meschia]

Why wouldn't it be possible with a monolithic LED? It would need to be driven with a variable duty cycle source, of course.

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[Nikola Nikolov]

Monolithic LED irradiates light like a cone. One can dim the LED, but you don't control the light cone.  Still loosing lot of energy because the light emitted the area around. Matrix LEDs illumination directs and shapes the light beam exactly where it is needed. One can dose exact illuminaton at specific surface shape. 

For example, matrix headlights can move the light beam with the steering wheel and follow exactly the road the car drives on. 

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[Vishal Kasliwal]

Forget about astronomy - I really dislike the overly aggressive garage lights that come on as you walk past houses. They are so bright that they destroy the pleasure of a simple evening stroll. I doubt Beethoven would have composed the Moonlight Sonata had he been subject to such lights. 

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[Akarsh Simha]

I’d love to read this county ordinance on light trespass that Stephen mentions.

On Mon, Jul 24, 2023 at 09:17 Vishal Kasliwal <vishal....@gmail.com> wrote:

Forget about astronomy - I really dislike the overly aggressive garage lights that come on as you walk past houses. They are so bright that they destroy the pleasure of a simple evening stroll. I doubt Beethoven would have composed the Moonlight Sonata had he been subject to such lights. 

I think these garage lights are in the spirit of IDA guidelines, though. Put lights on motion sensors — they’re not on all the time and when they’re on, you know someone is around. Of course there’s the question of how bright should it be and many of them are too bright. But these are much better then always-on lights for that false sense of security.

In the modern era, Beethoven has many alternatives to choose from: Gas station light sonata, Garage light sonata, airplane headlight constellation symphony…

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[Stephen Migol]

My message was too long as I attached a big file.

Here is the link for the zoning regs:  https://www.smcgov.org/media/101461/download?inline=

Original message:

Stephen Migol <stephe...@migol.com>	10:35 AM (4 minutes ago)
to sf-bay-tac

The ordinance is specific to my neighborhood North Fair Oaks and includes the language:

Section 6253.5 item 4 "Lighting. All exterior and interior lighting shall be
designed and located so that direct rays and glare are confined to the premises." See attached PDF page 118.

Most businesses in my neighborhood are non compliant with this ordinance.  However, it did give some teeth to my letter addressing the unshielded lights.  When I included some photos of street level and 2nd story views of the unshielded lights, it helped.

This does not help with residential light trespass except for the peaceful enjoyment of the property that is being trespassed upon.  

When I have approached neighbors, I've usually pointed out that the lights shine into our windows and point out that shielding to drop the level below the windows will be enough to satisfy the need

On Mon, Jul 24, 2023 at 10:35 AM Stephen Migol <stephe...@migol.com> wrote:

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