Article: the switch to outdoor LED lighting has completely backfired

ssanasisredna

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It's an example of the so-called Snackwell effect period since LEDs use less energy, municipalities are using more of them. Article at https://gizmodo.com/the-switch-to-outdoor-led-lighting-has-completely-backf-1820652615

I personally think it is a rather weak "study" and at best just feels like a bunch of conjecture with little underlying details ..

The statement "municipalities are using more of them" is just not true in the developed world. From experience in the market, they are using almost exactly the same and at considerably less power and typically quite a bit fewer lumens.

Where the change is is at the private level, whether that is residences leaving the lights on all night (far too common), brighter parking lots, etc. We see a large uptick in that area for outdoor area lighting around buildings, primarily private.

As stated in the article, developed world is fairly constant .. sort of as most in the industry expected.

The big growth is developing world. No surprise there. They want the same conveniences the rest of the world has.

We do need significantly more education and I hate to say it, maybe regulations to turn outdoor lights either off or down later in the evening.
 

Enderman

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So for the same or less power, you get more light.
How exactly is this bad...?
Isn't it the point to have everything well lit so you can see at night and reduce accidents?
 

MichaelW

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They changed the street lights, without any opinion sought from the public, to LED retrofit drop-ins. Cheapest & dumbest implementation: exposed LED array (two of them) so if you happen to look at it, very very high intensity. They didn't even bother to use some sort of diffuser. Now there is a general rectangular distribution, where there used to be a circle: this means that some homes are now receiving horrible blinding light, and yet the sidewallks are now dark.
And the cherry on top, they picked 5000k-and a low CRI too!
 

iamlucky13

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So for the same or less power, you get more light.
How exactly is this bad...?
Isn't it the point to have everything well lit so you can see at night and reduce accidents?

You're right to point out the increased light is generally not done arbitrarily, but fulfills some purpose, such as reducing accidents.

The real point, in my opinion, is to have light where you need it, when you need it, not everywhere. Light pollution is a distinct but related topic, however. The shift to LED's was not intended to reduce light pollution, although there is potentially some opportunity to do so since LED luminaires can be more easily designed to control beam patterns, and can generally dim or turn off more easily than types like sodium vapor lamps when not needed.

As to the article, I'm going to just go ahead and be blunt and say Gizmodo wrote a badly misleading headline (the article is not as bad) that they should be ashamed of, on what appears to be relatively interesting research:
http://advances.sciencemag.org/content/3/11/e1701528

Issues:

1.) The primary reason for switching to LED's is to save energy, not reduce light pollution as the article seems to imply.

2.) A 2.2% annual increase in lighting over 4 years corresponding to widespread adoption of lighting that offers often in the ballpark of 20-80% energy savings versus the types of lights it replaces is not a "backfire."

3.) The study is not capable of measuring changes in indoor lighting.

4.) The study observed a *decrease* in the rate of lighting growth post 2012 compared pre-2012 (2.2% vs 3.5%). However, keep in mind my 3rd point, as well as be aware there were methodology differences that make the different studies difficult to compare.

5.) The study mentions another factor that is relevant - historically, humans have tended to spend about 0.7% of their money on lighting. Decreasing lighting cost spurring more demand is one relevant takeaway from that, but far more significant, I think, is growing economies in less developed nations.

6.) The brightest lit countries such as the US and parts of Europe tended to have little to no increase in brightness over the study period.

Keep in mind that global population growth is about 1.1% annually. That population growth almost certainly explains part of the increase, although probably not quite proportionately.

Couple that with the fact that most of the worlds less developed nations, which also tend to have the least lighting, also have the fastest economic growth rates (China 6.7%, India 7.1%, Indonesia 5.0% vs United States 1.6%, all inflation adjusted), and there should be an expectation that a lot of countries are becoming increasingly able to afford to install lights in places we were lighting up decades ago in the US. The three countries I mentioned above alone account for 40% of the world's population, by the way, all rapidly growing.
 

Enderman

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They changed the street lights, without any opinion sought from the public, to LED retrofit drop-ins. Cheapest & dumbest implementation: exposed LED array (two of them) so if you happen to look at it, very very high intensity. They didn't even bother to use some sort of diffuser. Now there is a general rectangular distribution, where there used to be a circle: this means that some homes are now receiving horrible blinding light, and yet the sidewallks are now dark.
And the cherry on top, they picked 5000k-and a low CRI too!
Idk where you got the idea that bulbs have a circular "distribution", have you ever seen the filament in a bulb?
And roads and sidewalks are rectangular, not circular, so it definitely sounds to be like you're making up stuff about homes receiving "horrible blinding light".
Also the COB LEDs used are not very high intensity or blinding. They are just generally brighter, but they are producing the light output is much larger than that of a filament bulb.
 

iamlucky13

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Oct 11, 2016
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They changed the street lights, without any opinion sought from the public, to LED retrofit drop-ins. Cheapest & dumbest implementation: exposed LED array (two of them) so if you happen to look at it, very very high intensity. They didn't even bother to use some sort of diffuser. Now there is a general rectangular distribution, where there used to be a circle: this means that some homes are now receiving horrible blinding light, and yet the sidewallks are now dark.
And the cherry on top, they picked 5000k-and a low CRI too!

I dislike the 5000K also, but I'm not surprised at the mediocre CRI. Just trying to guestimate by staring at my skintones under lights in my area, I think they're probably in the high 70's to low 80's, but I don't have a way to be sure.

I understand using higher color temperatures on highways where alertness is an issue, but not in residential neighborhoods.

The LED streetlights in my do have a better beam pattern than the old sodium vapor lights. This graphic shows the sorts of pattern you might want depending on the road and light spacing, and in fact, on the better lights, the measured light distribution is actually weaker directly under the light, where the distance to the road is the shortest, so the illumination level is more consistent between lights.

http://www.ledfl.com/uploads/11FL-LD-QP04/led-street-light-beam-angle-1.jpg

This roughly matches what I see from local LED street lights when driving in the fog.

Most sodium vapor lights tend to have a closer circular pattern. Aside from not providing as even of illumination in between fixtures, they also cast a lot of light in the wrong direction - back towards the fields or homes behind the fixtures, instead of onto the road.

There's been some pros and cons with the LED's as they've been retrofitted in my area. I'd say they're mostly pros, but there's a few things they could still do better.
 
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