Changing yellow street lights to white

Kintarō Hattori

I posted in that thread last year when they started changing over from the sodium lights in the estate I live on. Recently an LED light was put in beside my house and I have to say, as much as I love technology and LEDs, I'm not a fan. It's rather polluting and the garden outside the window is very bright at night. I'm not looking forward to when they replace the light almost directly opposite the house.

Something that doesn't appear to have been mentioned on this thread yet- don't studies show that LED street lighting is very confusing to animals as they have trouble distinguishing between day time and night time?

They replaced a yellow one outside my bedroom window with LED white. At first I thought it was a particularly bright full moon.
But when it went on a few nights and I couldn't sleep with the brightness I realised it was a new bulb. Really disruptive if you're a light sleeper and its bang outside your window!

Quackster

RiderOnTheStorm wrote: »

Yup. The wheel is always turning. I remember when all street lights were white, and then they changed them to yellow. IIRC it was something to do with giving a more natural light as the white was very harsh.

Why can't there be yellow LEDs?

The first electric street lights used mercury-vapour lamps, which produce a rather ghostly white light. They were phased out in the 60s/70s in favour of low pressure sodium lamps (the really yellow ones) as these bulbs last a lot longer and are significantly more energy efficient. High pressure sodium lamps (the not-quite-so-yellow ones) were also subsequently introduced as they produce a less unnatural light than their low-pressure cousins.

The introduction of LED is just another step towards longer-lasting and higher-efficiency lamps.

wakka12

Looking at side by side I prefer the yellow. But the only reason I even noticed that the lights in my area had changed colour is because theres still one sodium one left that they havnt changed and you can see the contrast

Quackster

wakka12 wrote: »

Looking at side by side I prefer the yellow. But the only reason I even noticed that the lights in my area had changed colour is because theres still one sodium one left that they havnt changed and you can see the contrast

Yep, the issue here, as another poster pointed out, is that LED lamps with an unnecessarily-high colour temperature are being used for some reason. LED lamps with a temperature of 3000K would be perfect.

Effects

Suckit wrote: »

There must have been a reason in the earlier decades that softer colours were used. The ones near me are orange mostly, with some yellow. None are white.

Efficiency, so cheaper to run.

Effects

eviltimeban wrote: »

I do agree they could easily place a tinted cover over the bulbs, but that'd probably cost more money.

And it would cut down on the light output and visibility.

eviltimeban

Effects wrote: »

And it would cut down on the light output and visibility.

Not if it was a subtle tint.

astrofool

Kintarō Hattori wrote: »

Something that doesn't appear to have been mentioned on this thread yet- don't studies show that LED street lighting is very confusing to animals as they have trouble distinguishing between day time and night time?

The light is no more confusing than the old light, and because it can be more directed, it's actually less disruptive to the wildlife. Of course, it can be over installed causing issues, but so can the old lamps. The LED temperature can also be changed, but white light is the best at illuminating (which is their purpose after all) and hence used most often, the yellow "warm" glow wasn't so much selected, but was the default as that's the only colour they emitted.

TLDR: they could make the LED lights a carbon copy of the old HPS lights in glow and coverage, but it works against the purpose of the lights in the first place.

Dyr

Tell me how wrote: »

Yes. More energy efficient. Also, less light pollution.

You stop noticing the difference after a while.

The whole point of a street light is to produce light pollution

We have LEDs lights down our way, oddly enough you can hardly see a ****ing thing with them. Someone walks past you and you can't make out their face. I'd say Eamonn Ryan is delighted with them

Tell me how

Bambi wrote:

The whole point of a street light is to produce light pollution

Nor in the air above the light when it is focused downward it isn't.

Suckit

Bambi wrote: »

The whole point of a street light is to produce light pollution

We have LEDs lights down our way, oddly enough you can hardly see a ****ing thing with them. Someone walks past you and you can't make out their face. I'd say Eamonn Ryan is delighted with them

Well...... Not to produce light 'pollution'.


http://darksky.org/our-work/lighting/lighting-for-citizens/bad-streetlights/


http://darksky.org/light-pollution/

Capt'n Midnight

Harry Palmr wrote: »

The leccy bill for sodium street lights is massive - 25w per 250 lumen LED 4w per 250 lumen. Bulb 25k hours average v 40k hours average

Low pressure sodium isn't 10 lumens per watt :rolleyes:

Low Pressure Sodium - SOX
Energy Efficiency up to 180 lumens per watt.

And low pressure sodium is easier to filter out if you want to look at the stars.

Yeah it makes fire engine red look black, but our fire engines have a yellow / red pattern and blue lights so there's that.