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Are LED Street lights not so bad after all?


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So like most places in the UK my local council is slowly changing all of the old sodium street lights into the dazzling bright white LED lights. I'd been pretty annoyed about this because I have a street light directly outside my bedroom window and (more importantly) a couple visible from my back garden which I was worried would ruin astronomy.

However, few nights ago I happened to be walking through an area which had been completely switched over to the new street lights and I was pleasantly surprised. The lights themselves were very bright and would kill your night vision if you looked directly at them, but the area between the lights was lovely and dark. The light seemed to be very carefully directed with very little spillover into the sky or across the road.

I'm now starting to wonder if this switchover isn't so bad after all. My back garden is bathed in orange light all night at the moment, maybe it'll actually be dark once the LED street lights are put in. 

 

Anyone else noticed an improvement with LED streetlights?

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This LED street light is on, and view is from front bedroom. Can barely see it visually.

The local council for my area switched ours to LED a few years back. It made a massive improvement.  They also get turned off at 11pm.

The point about the broadening of the spectrum, in particular versus low pressure sodium, is valid.  A local imaging practiser was recently forced into switching to narrow-band only, due to the increa

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I have a bright sodium light that illuminates a lot of my back garden. Not too bad in the summer, when foliage from a tree hides it, but just now it's a real pain in the bum.

Edinburgh's street light upgrades has been delayed due to Covid, and our part of the city is the last to be done and now won't be completed until October this year. However, the rare times I have been travelling through the city centre recently, the difference is obvious. It's noticeably darker. Also, as I look West towards the city centre, the old yellow glow has now been replaced by a white one! 

I can't say whether it is improving the sky quality, but I can't wait until they replace the old streetlight at the bottom of the garden!

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We still have the old sodium here but there's a neighbouring estate that's new and has LED. Two of them are visible from my back yard and in my opinion they are far more obnoxious. The nearer, in particular, has all the LEDs creating star-like lights showing. I think a lot depends on the design (and no doubt the price). If well-designed they should be better but if they just buy on price and disregard good design then it's pot luck. Call me a cynic but I know which is more likely. I've also noticed several failing LED ones that just flash very irritatingly, seems to be a bit common failure-mode.

One advantage of sodiums is that a UHC almost kills them, with LEDs you're stuck with what LP they generate. Unless, of course, you don't want the UHC on!

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The switch to LED in my area was positive for me. But it depends on many variables including the location, height & design of the luminaries, the distance between them, the type of LED. I’ve also seen comments about the type of road surface- reflective or not.

Also depends  on whether the problem is light directly accessing your observing spot or general background light pollution. Former can be very hard to deal with 

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21 minutes ago, JeremyS said:

The switch to LED in my area was positive for me. But it depends on many variables including the location, height & design of the luminaries, the distance between them, the type of LED. I’ve also seen comments about the type of road surface- reflective or not.

Also depends  on whether the problem is light directly accessing your observing spot or general background light pollution. Former can be very hard to deal with 

I've heard that it's possible to discus with some councils about the addition of baffles on the lights to minimise spillage of light into (say) your property.  It's worth maybe asking your council if this is possible.

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At least sodium and mercury lamps have specific wavelengths that are easily removed. LED are broad spectrum which is more difficult to filter out.

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33 minutes ago, savcom said:

I've heard that it's possible to discus with some councils about the addition of baffles on the lights to minimise spillage of light into (say) your property.  It's worth maybe asking your council if this is possible.

Perhaps you meant to quote somebody else. I’m actually ok with the new LED lights where I live 👍🏻

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7 minutes ago, JeremyS said:

Perhaps you meant to quote somebody else. I’m actually ok with the new LED lights where I live 👍🏻

You'd made the point that the 'Former can be very hard to deal with'.  I was replying to that point.  Sorry for the confusion.

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I've LED lights around the streets but only two near me and the council put on baffles to the extent it's pitch black where my obsys are so I'm really pleased. Also the LEDs reflect light to the ground not into the sky so it's a marked difference. Where they've yet to replace the old lights in town towards the eastern side there is a slight orange glow. 

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The point about the broadening of the spectrum, in particular versus low pressure sodium, is valid.  A local imaging practiser was recently forced into switching to narrow-band only, due to the increasing prevalence of LED streetlights.

But unwanted light of any kind is only a problem if it is allowed to get away from its intended target.  Many LAs now recognize the importance of shielding and directing light downwards, but in my locality the bigger problem is the intensity. The things are so bright that, even when well-directed, the light reflected from the road surface is very significant (and even worse when wet). And of course the factors that make these lights worse for astronomers are often cited by others as positives: brighter than the old orange lights, and possessing a better colour rendering index.

 

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When we moved to our present bungalow we had the old type street light outside it was quite bright I phoned the council and believe it or not they turned up the following day and fitted a shade.  When it came to the light being changed  to led they replaced  the  whole top of the light so of course we lost the shade. I again phoned the council this time they transfered my call to the light installers. They were very curteous and explained that the light were designed to just luminate the area benearh  but realised that this did not all ways work and had ordered some shades and as soon as they  were available they would fit one.True to there word a few weeks later it was fitted. I was surprised how small the shade was  but the difference it make  was quite impressive.

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They are brilliant, in the best way.

They changed ours from sodium to LED a few years ago now, and the back garden went from having an orange glow in the sky and all around, to black, no stars to lots of stars, and now the milky way is visible. 

There is one outside the front  bedroom, but if it's not raining or snowing, or misty, you cannot see the light beam, it's very tight on the street below as well. There is one in the street some distance away, but it was easy to shade it with no glow in the sky above it.

This was a major factor in my taking up astronomy again after many years of not observing. 

The biggest problem now is neighbours, who have LED flood light's and leave them on in the evening for no good reason, or because they think the dog is blind and can't see in the dark 😤

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The local council for my area switched ours to LED a few years back. It made a massive improvement. 

They also get turned off at 11pm.

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I'm all in favour of the technology as long as used properly. I think if they could be made so that they are narrow band; ideally low pressure sodium wavelengths only, shielded and fitted with passive infra red detectors so they only are active when needed they would be the best thing since dark skies. It won't be perfect, but it'll be the best compromise possible for all. I do hate garden lighting and floodlights that are forever on. My neighbour has one that is on sunset to sunrise and there's absolutely NO off switch! The housing association or whatever it is that is responsible has fitted the damn thing with absolutely NO consultation with me. It has a pir detector on it, but doesn't seem to do a jot. I've gotten used to the school playing field's floodlights right at me because the DO get turned off about 2130 weekdays.  Not on at weekend at least. 

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The improvement with modern streetlights is that they point downwards in a controlled way with less stray light. Unfortunately it still reflects and being white LED is impossible to filter out at all. Better councils are turning some lights off after 11pm. If you lived near 24hr distribution centres and freight terminals you would realise this is only going in one direction!☹️

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I have a mixture here.  There's a lot of Sodium lights in the eastern distance, a logistics centre on the industrial centre to the north east - but pretty much no stray light and no street lamps near my garden until the local football club practice.  These latter are Mercury Arc lights: about to be upgraded to LED, so I will have to stamp my foot to make sure they're adequately baffled.

 

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The lights have made a noticeable difference where I live, also with all non-essential lights going off at midnight it darkens down no end, and for good measure when the regional council was going on this trip for switching to LED they put two bits of planning regulation on them so not only have they got to be downward projecting but also (except in certain mitigating circumstance) the light heads have to be lower than street side first floor windows.  Only time it's noticeable now is if there's humidity hanging over the valley floor; even my other half has noticed, which is surprising, to the point where she's actively taking an interest in looking up.

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1 hour ago, reezeh said:

I'm all in favour of the technology as long as used properly. I think if they could be made so that they are narrow band; ideally low pressure sodium wavelengths only, shielded and fitted with passive infra red detectors so they only are active when needed they would be the best thing since dark skies....

It's perfectly possible to make them sodium-colour. Use yellow LEDs instead of white, it's quite a close match and I can verify that a UHC filter cuts it drastically.

Advantage: the LEDs would last several times as long.

Disadvantage: lower efficiency (not seriously so but lower all the same) and no improvement to colour-index. Saying that, we've managed for donkey's years with sodiums.

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1 hour ago, Mr Thingy said:

The local council for my area switched ours to LED a few years back. It made a massive improvement. 

They also get turned off at 11pm.

The way it should be in my opinion. At the very least they should turn off say, 50% of them at 11 and have all off by midnight.

Round by me they don't turn off until 20 past 1 (or 20 past 2 in the summer) and they're back on again a few hours later. 

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