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68,000 white LED street lights - Sheffield UK

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#1 nytecam

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Posted 13 November 2012 - 09:05 AM

here

#2 Raginar

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Posted 13 November 2012 - 09:13 AM

Yikes. Not a good sign :(.

#3 JLovell

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Posted 13 November 2012 - 11:22 AM

One good thing about LED's is they tend to be quite directional. The video points out that light pollution from these lights will be almost zero, and that the orange glow from the town will disappear. I hope THAT part of the story comes true and spreads over here. They have to periodically replace light fixtures anyway as they age, why not use more efficient ones that last longer and reduce light pollution? Other than the cost, win, win, win!

I agree with most of the people they interviewed that during poor economic times the money could be better spent, or better yet, not spent by the government, but left with the people, but I don't want to start a political discussion.

#4 MawkHawk

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Posted 13 November 2012 - 11:36 AM

Well, it WILL make the "streets brighter and safer", soo.... How they arrived at this conclusion, we'll probably never know...

#5 FirstSight

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Posted 13 November 2012 - 12:40 PM

The biggest potential problem from white LED streetlights is an indirect one, in that the reason for the switch (far more economical lower power consumption) may also be the catalyst for an even-more profligate proliferation of lighting by businesses and homes. Although LED lights have the positive quality of being substantially more directional than mercury or sodium-vapor or incandescent or other previous-generation forms of lighting, when traveling down any street lined with commercial businesses, you can see plenty of examples of current-generation lighting that in principle is designed to focus light downward, but where the light fixture is mounted at a 30 to 60 degree angle with the idea in mind by its owner to broadcast the illumination from each single light over a broader expanse of e.g. a parking lot than if it was properly mounted shining straight down. It is likely that with the new LED lights, most of these same businesses will likewise mount them at an angle, and perhaps use even more of them since they're cheaper to operate.

#6 rdandrea

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Posted 13 November 2012 - 01:51 PM

Some of them also generate RFI like a banshee.

#7 Tonk

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Posted 14 November 2012 - 11:09 AM

Leeds (just north of Sheffield) has just finished its 5 years PFI relighting scheme - using older white light technology. They jumped too soon and missed out on LED.

Its a real hotch-potch in that they have used different coloured lights - some warmer coloured, some whiter, a mixture of full and semi cut off lamp designs. Looks like they had supplier problems or switched dues to costs. The interesting thing is I live north of and equidistant between two large cities, Leeds (white light) and Bradford (still sodium). I can see the light patches on the clouds from both cities - they are equally bright but one makes the clouds very white while the other patch is orange.

Even with an increased number of FCO lamps in Leeds we really have no improvement re the amount of light going upwards - mainly because the new lights are that much brighter and hence refelect more light off the ground and then upwards

It going to be interesting to see what the LED stuff in Sheffield will do - notably the news item didn't consider light reflected upwards.

One thing to note - from arial photography of many cities that I've looked at - it appears that car headlights and high rise office block are by far the major uplight contributers. This also tallies with the skies darkening after midnight as traffic subsides. I have SQM data that shows this for Leeds.

#8 TOM O

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Posted 14 November 2012 - 01:51 PM

IDA had some great info on the latest in LED tech at their annual meeting last week. Questions about LED applications and proper design using them is a top priority for IDA. It has become obvious that the current knowledge needs to be brought forward quickly as the next round of change may be 30 to 40 years in the future should white LED lights be installed now. The correct filtering and spectral output is a major concern, right now. IDA has lots of info..... Join them and join in building the solutions that will set proper action in motion....http://www.darksky.org/

#9 omahaastro

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Posted 19 November 2012 - 03:58 PM

My home town has been experimenting with a couple of blocks of these LED street lights... and like these, they are very much directional and shielded. I expect, replacing all the EXISTING lights with these, could have, very much, a positive effect on the light pollution situation.

#10 Achernar

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Posted 19 November 2012 - 06:03 PM

You realize they render all nebulae filters totally useless, and I suspect the narrowband filters used for imaging too. They may be directional, but the ones installed in my city are blindly bright, and light up the road far more brightly than the lights they are replacing. I expect governments at the local and state/province level will instally MANY more of them because they use so little energy compared to other types of lights. We are increasingly living in societies that amount to prisons, with day bright lighting at night a reality. I don't like living in a situation where almost day bright streetlights also shine into my home at night, which makes it very hard for me to sleep.

Taras



#11 Astrojensen

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Posted 20 November 2012 - 04:56 AM

You realize they render all nebulae filters totally useless, and I suspect the narrowband filters used for imaging too.


Is that really so? LEDs do shine equally bright across the spectrum, but the nebula puts out all the light in a very narrow part, so shouldn't the contrast still increase if you can filter 95% of the LED light away, while letting 95% of the light from the nebula through?

BTW, the streetlights on just ONE road near one of my friends house has been replaced with LEDs and he has measure a clear, stable improvement in SQM, from 17.5 - 18 to 18.5 (from what I remember) on average. And it was just on one road and not even the one next to his house.


Clear skies!
Thomas, Denmark

#12 FirstSight

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Posted 20 November 2012 - 09:02 AM

The benefit from LED lights being far more directional may be largely undone once businesses begin widely adopting them, due to the 30 to 60 degree angle at which many will install the fixtures rather than pointing the light straight down. Even with current sodium-vapor lighting, many fixtures are in use in businesses which are nominally designed as properly cut-off fixtures to shine light downward, but which in are nevertheless mounted by their owner at angles in an attempt to broadcast the light over a wider area. This sort of angled mounting scheme completely defeating the cut-off design feature. Yes, the big gain in lower operating costs from LED lights would in principle enable businesses to use a few more properly mounted LED lights (if indeed more would be needed at all) for less than the costs of operating fewer sodium-vapor lights they replace. However, many business-folk will still try to skimp on the up-front costs of the number of fixtures needed by installing the new LED lights at an angle, in an attempt to increase the broadcast area of each light so fewer total fixtures would be needed (so their thinking goes). And the businesses who don't think in this manner about the up-front investment in new LED fixtures may be inclined to install more and brighter lights than they had before using sodium-vapor lights, because the costs over time of more LED lights is lower (and more lighting seems better to many people).

#13 Achernar

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Posted 20 November 2012 - 09:09 AM

Not when the LED's light stream unimpeded through the filter and drown out light from nebulae. Previous types of streetlights emit light at wavelengths other than those of ionized hydrogen and oxygen. Not so with LED's, they emit light across the whole visible spectrum with no gaps. I suspect the low power consumption of these lights will lead to far worse light pollution that we have now in my country, there are very few places east of the Mississippi river where truly dark skies exist anymore. Right now a large city in my country creates a light dome that extends 250 kilometers in every direction. It will be even worse if all outdoor lighting is switched to LED's and they are allowed to bean sideways or even upwards. Even if they don't the ones in my city are much brighter than the old lights even when aimed straight down and they are nearly full cutoff light fixtures to begin with.

Taras

#14 FirstSight

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Posted 20 November 2012 - 09:56 AM

Has anyone flown over at night a city or town known to have switched over mostly or entirely to LED streetlights, and visually compared it to other cities and towns that have not yet made the change-over? Even an informal heuristic comparison of light domes along a night flight would be useful in this regard.

#15 tezster

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Posted 20 November 2012 - 09:29 PM

Funny this topic should come up. I just found out the city I'm living in are making the switch to LED:

http://www.mississau...e-light-on-leds

But it sounds like it's being done the right way, at least, with "Dark-Sky compliant" LED technology.

#16 JLovell

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Posted 21 November 2012 - 07:41 AM

With all the talk about businesses feeling like brighter is better, there is a reason for that. A sue happy public. My wife and I work for a major retailer, and every day we see what I'll call "fall artists" who will fill out an incident report and try to get the company to send them to the doctor if they so much as hiccup while they are in the store. If they slip and fall outside when there is ice and snow, they fill one out for that even if they aren't wearing appropriate footwear knowing what the conditions are. If they stub their toe at night, they try to say we don't have enough lighting, even though devices called flashlights exist. They knew it was going to be dark.

Read all the warning labels on a product sometime. Some of them will have you saying "DUH! Who would do something THAT stupid? Why do they feel the need to warn people not to do that?" The reason is lawsuits. Someone, somewhere, did that stupid thing and got hurt. The sued the company and won because they hadn't been warned to not use the product in whatever way that particular dumb person did. Until courts worldwide go back to where they expected individuals to use some common sense, and exercise some personal responsibility, and not allow essentially frivolous lawsuits for things a company really is not "at fault" for, companies will continue to over light their property, among other things.

#17 csa/montana

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Posted 21 November 2012 - 10:01 AM

If they stub their toe at night, they try to say we don't have enough lighting, even though devices called flashlights exist. They knew it was going to be dark.


frankly; I don't know of anyone that would carry a flashlight with them in order to get into a store, shopping. :confused: It is up to the businesses to provide a safe enviroment for shoppers. While I agree about frivolous lawsuits; I believe the reason businesses are so overly lit up, is to "advertise" that they are there. They could install lighting that is shielded, and still provide adaquate lighting, and not have so many lights.

#18 BPO

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Posted 22 November 2012 - 02:02 AM

LP exists outside the USA.

#19 George N

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Posted 24 November 2012 - 10:39 PM

The benefit from LED lights being far more directional may be largely undone once businesses begin widely adopting them, due to the 30 to 60 degree angle at which many will install the fixtures rather than pointing the light straight down. .....


Another reason to work for anti-LP laws, which can require straight down installation.

However, I doubt that anyone will be installing parking lot lights any way but how they are designed – full-cutoff and aimed down.

Otherwise I still think the new LED fixtures being sold are far better at cutoff than the older ones, if for no other reason than the light does not hang down below the metal part.

#20 George N

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Posted 24 November 2012 - 10:41 PM

LP exists outside the USA.


Well there are two countries with little LP: North Korea and Cuba. I like rum and Afro-Cuban Jazz, and I’m not a big fan of kimchee, so guess which one I want to move to.... :cool:

#21 GeneT

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Posted 03 December 2012 - 10:13 PM

LP exists outside the USA.


Well there are two countries with little LP: North Korea and Cuba. I like rum and Afro-Cuban Jazz, and I’m not a big fan of kimchee, so guess which one I want to move to.... :cool:


:grin: :grin: :grin:

#22 DarkSkys

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Posted 03 December 2012 - 11:34 PM

Yakima has installed a few on a few street's. They are insanely bright, incredibly " cold" white/bluish color. The glare they throw off at night with wet streets is horrible.

If there needs to be a case study done on how "Moar Light
s" doesnt makea safer town, they need to do it on yakima.
All it seems to do is give the bad guys better lighting to steal/aim by. :(

#23 Achernar

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Posted 04 December 2012 - 07:05 PM

As I have said earlier, nebula filters are totally useless against LED lights, which blanket the whole visible spectrum with NO gaps whatsoever. These lights are going to make light pollution much worse, especially once they are cheaper to produce than the older high pressure sodium and metal halide lights that are being replaced by LED lighting. The ones in my city are nearly full cutoff lights, but they are blindingly bright.

Taras






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