The argument for switching off lights at night(bbc.com)
bbc.com
The argument for switching off lights at night
https://www.bbc.com/future/article/20210719-why-light-pollution-is-harming-our-wildlife
32 comments
My neighborhood in Washington, DC recently replaced a number of old sodium streetlights with new LED streetlights. The number of lights was doubled, but power consumption was still halved. The ballasts on the LEDs angle down at about 45 degrees—light pollution is reduced by 80% as a result.
The LEDs are a much brighter color temperature but I worked with the city to get them reduced from 4000K to 3000K (which has very little blue light).
All in all, a big win. There are technical solutions these days, and they pay for themselves. However, municipalities often operate on auto-pilot; let your local officials know where you want them to head.
The LEDs are a much brighter color temperature but I worked with the city to get them reduced from 4000K to 3000K (which has very little blue light).
All in all, a big win. There are technical solutions these days, and they pay for themselves. However, municipalities often operate on auto-pilot; let your local officials know where you want them to head.
Isn’t the ballast only required for a fluorescent bulb?
They meant the LED device, ie “bulb.” DC’s transportation department referred to it as a ballast; that might be inaccurate.
They probably mean lampshade / directionality. Ballasts are a current-limiting device, they would not influence the light geometry.
> the LED lights are a hard blue light
The Dark Sky folks recommend <3500K for colour temperature:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
Another criteria to get their seal is controlling the angle that the light comes out to control for glare and such. Roadway lighting:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
Street:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
The Dark Sky folks recommend <3500K for colour temperature:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
Another criteria to get their seal is controlling the angle that the light comes out to control for glare and such. Roadway lighting:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
Street:
* https://www.darksky.org/our-work/lighting/lighting-for-indus...
And it doesn't even have to be that way! We have the power to choose something different. I've seen nice indirect lighting fixtures that aren't nearly as harsh, or lights that are warmer. They're just not the norm.
Or frankly just don't have street lights. I moved somewhere that doesn't have them, and I don't miss them at all. And I found out that I did miss darkness and was glad to reclaim it.
Illuminated billboards should just be illegal.
Or frankly just don't have street lights. I moved somewhere that doesn't have them, and I don't miss them at all. And I found out that I did miss darkness and was glad to reclaim it.
Illuminated billboards should just be illegal.
You might have a different opinion of street lights if you've ever had to walk alone in the dark.
Given that I live in an area that's dark, I walk alone in the dark all the time. I'm just one of the lucky minority of people that manages to escape being ruled by unsubstantiated or irrational fear.
Fear of stepping on something or falling or worse is not all that irrational. One might say your stance seems reckless or irrational.
I was actually thinking of crime, etc. Even if you live in a safe area, darkness creates opportunities.
And while I'm hesitant to bring this into it—if you're a man, consider if you weren't.
And while I'm hesitant to bring this into it—if you're a man, consider if you weren't.
I don't need to illuminate the whole space all night to see where I'm going. I carry a flashlight on night walks. It light pollutes only the area right in front of me.
Cool. I used to walk in the dark all the time. Then I got held up at gunpoint. It was not at that point practical for me to avoid walking in the dark, so I continued, though trying to be more aware of my surroundings. But such fear as I felt did not seem unsubstantiated or irrational.
My city replaced it's old sodium lights with LEDs this year, and I was afraid they would do something similar but it's actually much better.
The LEDs they installed have a much narrower beam, around 45 degrees vs 180 for the sodium lamps. My apartment is at the level of street lamps, so the light would shine in directly through the window in the living room. Now I get only reflected light in.
The LED lights have around the same intensity as the sodium lamps, and because of the smaller beam angle, streets feel darker. However as the light is directed mainly on the road, it doesn't have any impact on driving.
The colour temperature is around 3500K which is still a bit colder than what I'd prefer. The colour temperature of sodium lamps definately invokes feelings of nostalgia. Part of this is because getting warmer than ~3000K LEDs is basically impossible as there is very little market demand, so nobody makes them.
The LEDs they installed have a much narrower beam, around 45 degrees vs 180 for the sodium lamps. My apartment is at the level of street lamps, so the light would shine in directly through the window in the living room. Now I get only reflected light in.
The LED lights have around the same intensity as the sodium lamps, and because of the smaller beam angle, streets feel darker. However as the light is directed mainly on the road, it doesn't have any impact on driving.
The colour temperature is around 3500K which is still a bit colder than what I'd prefer. The colour temperature of sodium lamps definately invokes feelings of nostalgia. Part of this is because getting warmer than ~3000K LEDs is basically impossible as there is very little market demand, so nobody makes them.
It's easier to filter out the old sodium lights, too, for astronomy and astrophotography. (although these are essentially hobbies... I do think the other broader arguments in favor of stopping light pollution and making the night sky visible to people again are stronger.)
I was frequently walking my dogs at night when they made the switch in my town. I noticed I my visibility was greatly reduced because the LED lights were less diffuse. Anything under the lights I could see just fine but a few feet away was under the vale of darkness.
That may be somewhat intentional.
There has been more focus lately on reducing light pollution by ensuring light is projected towards the ground. It's true that LEDs are more naturally directional than other types of lamp, but mirrors and lenses can adjust that if desired.
There has been more focus lately on reducing light pollution by ensuring light is projected towards the ground. It's true that LEDs are more naturally directional than other types of lamp, but mirrors and lenses can adjust that if desired.
A lot of lamps in the past had little cut-off, sometimes sending light straight up.
New designs, especially Dark Sky approved ones, tend to concentrate a lot more light straight down (0˚), with some spill over over out to 60˚ to the side, but having a hard-ish cut-off by 80˚.
If you simply do a 1:1 replacement of street lamp heads, the new more narrowly-focused units will of course not "splash" light as far—but who wants to install new poles for the new design?
New designs, especially Dark Sky approved ones, tend to concentrate a lot more light straight down (0˚), with some spill over over out to 60˚ to the side, but having a hard-ish cut-off by 80˚.
If you simply do a 1:1 replacement of street lamp heads, the new more narrowly-focused units will of course not "splash" light as far—but who wants to install new poles for the new design?
LEDs can be just about any brightness and color, your city just chose harsh blue ones!
You might be interested in this video https://www.youtube.com/watch?v=wIC-iGDTU40.
I think people would be much healthier if we allowed the night to be dark. Personally I sleep much better in darkness. I don’t really understand why everything needs to be lit up at night.
Presumably there is perceived safety, both from crime and when operating a vehicle. Whether the data confirms this or not is unknown (to me).
Bad lighting can actually make things worse because of (blinding) glare and shadows:
* https://www.darksky.org/light-pollution/lighting-crime-and-s...
Proper lighting does seem to help reduce crime:
* https://urbanlabs.uchicago.edu/projects/crime-lights-study
* https://www.strongtowns.org/journal/2019/5/9/how-something-a...
Study is ongoing:
* https://theconversation.com/the-science-of-street-lights-wha...
I'm curious to know if motion sensors can be used to turn off lights when people aren't around, but switch things on as they're in the area, and a few lights down the street as well so they can see what's up ahead. I doubt there's many folks around between (say) midnight and 5, and so some energy could be saved.
* https://www.darksky.org/light-pollution/lighting-crime-and-s...
Proper lighting does seem to help reduce crime:
* https://urbanlabs.uchicago.edu/projects/crime-lights-study
* https://www.strongtowns.org/journal/2019/5/9/how-something-a...
Study is ongoing:
* https://theconversation.com/the-science-of-street-lights-wha...
I'm curious to know if motion sensors can be used to turn off lights when people aren't around, but switch things on as they're in the area, and a few lights down the street as well so they can see what's up ahead. I doubt there's many folks around between (say) midnight and 5, and so some energy could be saved.
This would make things worse on streets that have even a moderate amount of traffic (4 people per hour) as lights switching on and off is far more distracting than ones that are on continously.
Depends on the settings. Limiting it between midnight and 4 or 5, when there's probably the fewest number of people awake, would be one way to minimize switching.
Whether it's a fast on-off or gradual would also probably determine how disruptive it would be.
This would also be done mostly in low-traffic areas, and that'd be relatively easy to determine because you'd have motion sensors to measure things. Heuristics could be determined to see traffic patterns: more people are likely to be out late on Friday and Saturday nights than on a random Tuesday at 0300.
One experiment found an 80% reduction in electrical use:
* https://newatlas.com/motion-sensing-streetlight-system/19199...
At the very least a system like this could perhaps be done for parking lots, which generally see little activity in the middle of the night. There's a lot of empty asphalt being lit up now.
Whether it's a fast on-off or gradual would also probably determine how disruptive it would be.
This would also be done mostly in low-traffic areas, and that'd be relatively easy to determine because you'd have motion sensors to measure things. Heuristics could be determined to see traffic patterns: more people are likely to be out late on Friday and Saturday nights than on a random Tuesday at 0300.
One experiment found an 80% reduction in electrical use:
* https://newatlas.com/motion-sensing-streetlight-system/19199...
At the very least a system like this could perhaps be done for parking lots, which generally see little activity in the middle of the night. There's a lot of empty asphalt being lit up now.
A lot of things are either only possible at all, or a lot safer, with light. A simple example is driving, the more you can see the safer you are. Environmental lighting is a big part of this, particularly in countries with tyrannical policing of anti-modification regulations like Australia or (even more so) Germany.
Anecdote: My old Mazda was the top-of-the-line when it was made, the nicest road car you could get from Mazda no matter how much money you had. And the headlights were terrible. Well-lit streets were always noticeably easier to drive at night. I could have replaced them with a HID or LED for less than a thousand dollars, and been much happier and safer, for a week. Then I'd be pulled over, given a defect canary (a fine, a huge sticker on your windshield labelling you to other police to harass, as well a requirement to prove you've "remedied" the situation). Get a few defect notices, and the police can have your car crushed into a cube with no recourse under "anti hoon" laws.
Anecdote: My old Mazda was the top-of-the-line when it was made, the nicest road car you could get from Mazda no matter how much money you had. And the headlights were terrible. Well-lit streets were always noticeably easier to drive at night. I could have replaced them with a HID or LED for less than a thousand dollars, and been much happier and safer, for a week. Then I'd be pulled over, given a defect canary (a fine, a huge sticker on your windshield labelling you to other police to harass, as well a requirement to prove you've "remedied" the situation). Get a few defect notices, and the police can have your car crushed into a cube with no recourse under "anti hoon" laws.
how I'll walk to home when drunk at night without streetlamps? :|
damn, those trade offs!
damn, those trade offs!
I really hope that sometime in the next 20-30 years light pollution gets the attention needed to do something about it.
Especially since in many cases the better lighting is as cheap or cheaper (tco), it just takes someone in the decision tree actually caring.
Especially since in many cases the better lighting is as cheap or cheaper (tco), it just takes someone in the decision tree actually caring.
> … it just takes someone in the decision tree actually caring.
Right there is pretty much exactly why light pollution won't even matter in 20-30 years. People in decision-making positions don't care about anything except money and power. Because of that little detail, we're all gonna have much more serious things to worry about than light pollution or street light energy usage 20-30 years from now.
Right there is pretty much exactly why light pollution won't even matter in 20-30 years. People in decision-making positions don't care about anything except money and power. Because of that little detail, we're all gonna have much more serious things to worry about than light pollution or street light energy usage 20-30 years from now.
First World problems here guys.
Sorry but this is absolutely impossible to implement in any second/third world country with high crime rates.
Please, don't misunderstand me, but everybody here should take a walk in the suburbs of any South American country to be convinced otherwise.
Anyway I admire the noble idea of the creator of this article.
I used to live in a city with light pollution laws. It was always nice being able to see the stars from virtually anywhere in the city. I now live in a regular city without such laws and I haven't seen stars since the last time I traveled. But it's not just about seeing the stars, it was that night felt like night, but now night is so lit up being out here that I frequently see drivers at night without their headlights on, probably because it makes little difference to the driver and they can't really notice them not even being on.
Perhaps they use less energy, but the color, not to mention the brightness, is deeply unpleasant. I've wondered how these new very bright LEDs will affect wildlife and insects. Not positively, I think.