get rid of them!. cars now look at and watch pedestrians ,no privacxy from someone maybe stalking you. no more intimate ''nightime'' dog walk privacy whatever. you are always on display. never any private calm walking with white lights third degree always on you. a woman walking might not want to be watched by cars a block away. you want some mystery in your leisure beneficial evening relaxing. neon parking lot is what the tree city has become ,indeed the whole plenty. invasion of privacy ''lights''.

Looking forward to them on our street. The lights at present are much too dim, hidden by too many trees and practically useless. In winter it is almost impossible to find a house number from the street unless they have a light over the number. No wonder burglars think this is a good area, they can do what they like and no one is able to see them.

How will the new LED lamps effect the light pollution on Mt Hamilton's Lick Obseratory? The yellow lamps from the HPS lamps were picked decades ago to keep the city lights from ruining the quality of astronical observing at Lick.

> to keep the city lights from ruining the quality of
> astronical observing at Lick.

Public safety has to trump "astronomical observing". If the light pollution gets to be too great for Lick, then it's time for them to abandon this site. There are many better places for these sorts of operations than on the edge of the Silicon Valley.

While we are slated to get them for a year or so we seem to have them already! Verdict= light spread is great, lights are too bright, light color is very poor with a poor color rendering index. The light sucks the color out of the surroundings and things look dim and gray. A warmer color temperature (less blue) should be easy and better. CRI is readily available but not at the lowest bid. We better get it wright though because we are stuck with these for 20 years. The new heads on the old poles with their paint falling off look silly
Did the city listen to the feedback? I emailed them a ways back after the install with zero response. I don't think they listened....

"The light sucks the color out of the surroundings and things look dim and gray."

But what is the CRI of the sodium vapor lights? As for light pollution, the LED lights are highly directional, so less light escapes upwards.

I *hate* the new lights, have complained about them, and have received no feedback.

The lights are too bright, but that isn't the big problem.
The big problem is that it doesn't shine onto the street-- it shines INTO my house so strongly that I cast shadows on the inside walls.

They are NOT well thought out.

[Portion removed by Palo Alto Online staff.]
LEDS are great and good for the environment

The new LEDs are a step in the right direction. Not yet perfect, but given the improvement over Sodium Vapor lighting...we can handle this.

Remember:the sodium vapor lights have VERY poor color rendering, eg all colors looked like mud. In fact, this makes the light from sodium vapor lamps less save than the more broad spectrum LEDs as there is little color contrast information provided to your eyes.

I agree that the installed LED color temperature is too cool. Using replacement lamps with a warmer hue will make the transition from Sodium Vapor to LED much more enjoyable.

Keep up the good work! These should save the City a ton of cash.

Note that warmer hue requires cooler color temperature. (Red hot is cooler than white hot which is cooler than blue hot.) Helps to keep the terms straight when advocating an adjustment.

One point in the article says "Getting used to the bluer light can take some time." Actually as we age, the bluer light scatters more in our eyes. And it scatters more in the windshield and more in the air. This is why fog-lights are yellowish, away from the blue end of the spectrum.

A reason the LEDs seem so bright is they are effectively point-sources, like bare filaments. Some sort of diffuser like a frosted glass panel might be helpful, but would compromise the directionality of the beam pattern.

The only thing convincing me of budget savings is lower maintenance cost due to longer lifetime between lamp replacements. I need to look at energy efficiencies again. Are these LEDs the type that emits UV and converts it into white light using a coating of phosphors? I also believe that when installed, they are twice as bright as necessary so that as they age and decay over the next ten or fifteen years they stay above the minimum desired luminance.

I remember the issues getting complicated when we had the neighborhood meetings about the new streetlight initiative a few years ago. And since most of our burglaries happen in the daytime, I doubt that streetlighting can make much difference there.

"Are these LEDs the type that emits UV and converts it into white light using a coating of phosphors?"

No, they naturally emit blue light and have phosphors that convert some of that blue light into yellow to create white.

There are so many pedestrians getting hit by cars these days. This is especially a problem during the winter when rush hour is in the dark. Please make the street lights brighter, especially at intersections and crosswalks. And car drivers, please slow down when driving in the dark on city streets. You have tremendously better peripheral vision and reaction time at lower speeds. Thank you.

Why does everyone seem to be so preoccupied with such things as color rendering, brightness at night and invasion of privacy while walking on public streets?

The point of this change is to reduce the energy consumption while making our previously dimly lit neighborhoods safer . . . which has been admirably accomplished on my street in Professorville. Before the switch to LEDs the street lighting was so poor that is was downright scary to walk home at night from downtown. Now that our block is fully illuminated I feel much safer. I'm also willing to bet that over time the improved lighting will reduce vehicle break ins and vandalism throughout the city.

I'd definitely be interested to know if any attention was paid to the affects of light pollution with respect to viewing the skies for everyone from Lick Observatory astronomers to avid amateurs to casual star-gazers -- this is not an unimportant factor of quality of life for many, and I hope consideration was, or could be, factored in to all the various considerations -- energy-efficiency, cost, brightness, quality of light (cool, warm, color, etc.), coverage, etc. of possible lighting schemes....

Brightness: I find it ironic that we're switching to LEDs for more lumens/$, then adding filters that reduce the lumens, yet don't save any watts.
Color: What is the color of the lights (in degree K)? The first LEDs I installed in my home were too white. Now I won't buy anything above 3000K and prefer 2700K.

The following link has some before/after photos comparing HPS to LED streetlights in Los Angeles:
Web Link

Dan

Thanks for this link. This photo Web Link seems to show the before and after best. The yellow has too much glare and is very difficult to see. The white makes for much better visibility for cars and pedestrians alike. The shadows in the second shot seem to be smaller also. I know which one I would like to walk or drive down at night!

Ok the web link takes you to the main page, click on button for more information and then click on before and after button.

Thanks for the upgrade. This was long overdue for West Meadow Drive. Currently there's a mix of both the old and new lights on our street so it looks incomplete.

"Are these LEDs the type that emits UV and converts it into white light using a coating of phosphors?"

Yes, that is how they work - the LED itself emits mostly UV which excites the phosphor. Most of the UV is converted to white light by the phosphor, very little is actually emitted directly.

Saving energy and better safety are good goals but the LEDs are blinding. Too much direct glare coming from them. The bugs need to be worked out better on this technology/project before they roll them out across the City. After all even though they may save energy and money in the long run I understand they cost more per bulb up front. So we better get it right before we scale them because we are going to need to live with them for a long time to reach break even.

GREAT WORK ...

These lights are so much better than the old lights.
Yes, there is more light, that's the point.

Every time I go for a walk at night I'm reminded of
the terrible old lights when the light cycles off and on
it's really irritating - and there are a lot of them all
the time that are doing that, and the city never
checks it, notices it or fixes it.

A big improvement.

"The following link has some before/after photos comparing HPS to LED streetlights in Los Angeles..."

These photos show conclusively that LED-lit streets are dimmer than HPS lighting. The dark spots in the "before" photos are caused by the fixture hoods, not by the nature of the lighting elements.

My first-hand looks around Palo Alto confirm this. LEDs drop dim gray light where there used to be bright warm light. While it's more uniform on the street, it's uniformly dimmer.

Sure, they are different than the street lights they replace, but after a week or two of getting used to them, I actually like them.

If it were simply a matter of more light, we'd all drive around with our high-beams on.

I first noticed the new lights riding my bike down Park, where I saw interesting striped patterns of light and dark on the pavement. I then made the mistake of looking up at the street light. The grid of bright points which got seared into my vision confirmed that the pattern was from the LED distribution.

A few nights later, I looked out the front door and thought there was a full moon, according to the brightness and color of the street. Then I realized my street had been retrofitted.

HAPPY with the new lights! With so much crime in the recent months, the bright lights make me feel much safer when I walk out to throw away garbage at night... when I return home after dark... etc. Safety & Energy-wise = win win!

pot smokers have noticed things you don't. notice thge light makes neighborhoods lookj anonymous!! no longer the unique character of a town ,but it makes it all look homogenized white light somehow ''neutralizes'' the nooks and crannies of trees and architecture. it can make a palo neighborhood look lioke hoboken or wherever anonymous town. homogeneous white glow that covers everything blocking the familiar strret designs you are familiar with. notice, lioghts make the neighborhoods look homogeneous. notice it!

hi peeple shuld use spiel checkers

These lights make Palo Alto look like a slum at night.

The problem is downplayed by the City as "only dozens of complaints amongst thousands of LEDs" but then they go on to say "it could take several weeks before an evaluation is done, due to the volume of requests."

Hmmmmmm....

As the manufacturer of these lights I have a few comments:
1) Whenever street lights are changed, some people like the new lights, some people don't, and many people don't notice. There is a strong subjective component to evaluating street lighting. This is why it is important to get as much community input as possible.
2) As LED color temperatures get warmer (more yellow), they get less efficient. The 4000K (neutral white) is the most popular because it most closely matches moonlight and is considered the most natural. This is what Palo Alto used. Except for sodium lights which are used for their efficiency and low cost, 2700K lights are typically used inside because they more closely match candlelight and incandescent.
3) The City of Los Angeles has now installed over 100,000 LED street lights (4000K) and the have seen reductions in crime, improved visibility, over 60% energy savings, 75% reduction in maintenance costs, and a significant reduction in their urban sky glow.
4) Unlike sodium lights, LEDs contain no mercury.

I too hate these bright led lights. No privacy, no peaceful walk at night. What happened to the "dark skies" movement? I would have thought a city like PA that takes care of its trees seriously would be mondful of a peaceful night as well. I think I now live in a yucky urban environment where there is no night sky. I do miss it. Night sky is as important to our bodies as day time sunlit sky. Can't we put a cover and make them fuzzy and directed down so the light does not leak upwards?

Privacy? On a public street? If you want privacy, go back in your house and draw the shades.

I grew up on Washington Avenue in the '60s and '70s when the street had incandescent lights. The incandescents were replaced with orangey sodium vapor lights without lenses or diffusers. The lack of lenses or diffusers caused the light not to be spread out, therefore the roadway was well illuminated but the sidewalks and houses were pretty much in the dark. From the standpoint of illumination quality it was a giant step backwards from the old, energy-inefficient incandescent lights.

I thought that one reason communities used Sodium lights was to minimize light pollution that would affect local science programs at observatories,-- and that this was because the wavelengths of light emitted by Sodium lamps could be easily filtered from astronomical observations, in contrast to broad spectrum light which could not.

I am aware of the observatory at Foothill College (which is surrounded by relatively bright lights), and also Lick Observatory atop nearby Mt. Hamilton. Perhaps there are other local observatories, including backyard observatories that might be impacted by this switch to white light LEDs.

I hope that any impact to the science programs at local observatories was considered as part of the decision to switch to LEDs.

@Chris Nye, thanks for your professional inputs. Great idea to monitor community comments where your products are installed, though you've probably heard it all by now. LEDs are clearly the future of lighting. As for streetlights, as you say, people will always vary in their preference for color, brightness, and distribution.

@Phil, I think we lost the science battle. We're surrounded by bright lights but dim bulbs.

@Shadows

You might want to contact the city and ask them to install a shield on the street lamp fixture to block the light from reaching your windows.

I sympathize with your light intrusion issue: three separate neighbors have bright lights poorly shielded such that when they are on they light up either our offices, our master bedroom and bath, and/or guest bedroom.

Don't people have shades, drapes or curtains? Or do people like being on view when they turn their lights on? Sensible window coverings should stop the problem from the bright lights. They should help to keep the house warmer too.

We darken our windows before turning on our lights. We are not bothered by lights from neighbors and they are not bothered by our lights.

Now noise, barking dogs, etc. That is another matter.

I now feel like I live in a used car lot. We have fences around our house, and like to leave the shade open to get air at night. I can not leave the shade open at night now, as it is so light in my bedroom that I can read at night with the light off!

To be fair, Palo Alto is working with me to lessen the light. They have turned down the light, and added the shade around the light and it is still so bright there are shadows on the wall. I have 4 lights around my house so we are really lit up.

In my living room we have half shades (on the bottom for privacy). My mother in law asked me to close the shade all the way as the light was in her eyes while sitting on the couch.

I am very upset about the ugly green glow around the house. I am upset that our hot tub is now in full light. I am upset we cannot see the sky. I hate these lights. I want to move :(

now your personal environment looks just like tghe neon office building you work in.perfect!

These are TERRIBLE! It's immense light pollution that pours into my bedroom at night, making it seem like daytime. Bad for the circadian rhythm. Likewise, it's dangerous while driving. The new lights beam you in the eyes, causing distraction and momentary blindness. Please go back to the other ones! Or at least find a better solution. These are awful. Makes me want to move.

These new lights are an assault on the already-bad light pollution issues. Isn't there some kind of shade that can be put over them and/or a reduced wattage that can be substituted?

The intensity and COLOR TEMPERATURE of the newly installed street lights in my neighborhood are unacceptable. This is light pollution at its worst.

We used to have dim, yellowish street lights in the neighborhood with minimal light penetration into our bedrooms. This has now profoundly changed with the new, bright, laboratory-like color temperature LED lights. There are now three street lights shining brightly into our bedrooms. This light pollution will get even worse after the city trees lose their leaves.

It is unhealthy and evolutionary incorrect to be exposed to light during sleeping hours. Also, studies have shown that light exposure in children while asleep predisposes them to myopia and increases their likelihood of needing eyeglasses.

This light pollution must be corrected. Please (1) reduce the intensity of the LED street lights and (2) change the light color temperature by providing different color LED's or with a shield. Please expedite these corrections so that they are completed before the deciduous city trees lose their leaves.

People should address concerns such as the above directly to the city staff, probably utilities, rather than assume that posting here will bring it to the right person's attention.