White street lights and light pollution

[Robroy]

I see what the cooncils are trying to do, but I've got a feeling it'll be a false economy, where I work we use LED arrays in our cameras and the LED's dim significantly after just a few years use.

So unless the ones been used to light streets have a much longer life than the ones we use, then the cooncil could find themselves footing an expensive replacement bill.

In fact, I reckon the problem, given a bit of time, might not be that bad for stargazers.

I hope so anyway.

[ncjunk]

Not wishing to panic too much first, i would want to know:

1. Why is white light chosen? Would this impact pedestrian safety if they lose night vision and walk to a dark area....are current lights a problem in this area.

2. Is there no light leakage and are the properties of the reflected light off the road enough to reduce light polution? (what % is reflected and what does the transmition graph look like)

3. What impact does dimming have?

4. What is the calculation for distance between street lights based on? Can this be increased with new lighting or will old lights just be automatically upgraded for cost reasons.

I am quite interested in the details, i suspect there are pros and cons to this.

[earth titan]

Having talked with the guy from the council, I can see the logic. Because they are using white light (not LED interestingly) they reduce the overall power usage while improving visual perception. The eye responds better to white, so contrast is improved. Grass looks green, water is evident etc.

As for reflection, I don't know.

I'm going to compile a letter to the council about the lights opposite my house but I think this will be the best I can hope for. Can't see a succesful campaign based on 'What do we want ? Worse lighting. How much do we want to pay? More!'

[ncjunk]

I think the best we can hope for is well directed, dimmed, white light sources by the sound of it. May well turn out generally better.

[Rols]

long term cost to wildlife might not be as easy to shrug,they may find they end up with green issues if all the moths die, the birds call in the middle of the night, and the Owls die off,and lose frogs, ahh, thats not realy a problem though is it? i mean atleast we humans will be able to see our feet at night....and the OAP walking the streets at 2-3am will get home safely. maybe we can get our bins collected in the middle of the night aswell, see if the windows cleaner dont mind coming in at midnight! the future looks great or should that be the future looks bright! the good thing is Phillips wharehouse staff will be ok, and the tax payer wont mind downgrading in 10 years for another few million out the coffers! i was thinking maybe in England we can ask them to turn on the new economy lighting on dull cloudy days so i can see aswell in the day as i can at night!!?

i am ashamed i was able to rant like a child, but better now!

[JamesC]

....and the OAP walking the streets at 2-3am will get home safely.

Yep, that's the real joke. There really aren't that many people around at 2-3 - at least in the 'burbs. Town centre's a different matter of course, but even there how many people are still around come 3.30? And yet the lights blaze away all night long. Mindless opulence. Of course power stations produce a lot of power no-one is using at that time - maybe we should all buy electric cars to raise the demand for electricity late at night and make lighting more expensive...

[Psychobilly]

The only practical experience i have so far with these LED downlighters is that the sky above is darker but under neath then its much brighter... and looking in the direction of one of them really screws up your dark adaption...

[Dangerous-Dave]

Quick update on the situation and will continue to follow on this.

Just had a chat with the guy in charge of the project in Northamptonshire. Very nice chap and very helpful.

The start of the project is June 2011. It will take around 5 years and all lights (low pressure sodiums - the yellow ones) will be replaced by the Philips Cosmopolis. The plan is for these to be dimmed to 40% power after 22:00 hours and the anticipated light spill onto surrounding properties will be less than current lamps.

Before and after shot below:

http://www.newscenter.philips.com/pwc_nc/main/lighting/resources/press/press_cosmopolis_case_study_june/press_be_af_05_600.jpg

We have two lamps visible from our garden, one of which shines directly down the garden. I can currently filter this out and I see little prospect of changing the councils mind on this. Energy bills reduced by 40% and 'improved' lighting.

That looks blumming terrible, these things have to be stopped. Anyone contacted CFDS yet?

[Psychobilly]

Dont they (CFDS) like them ?

I thought they did because above them its darker?

[Dangerous-Dave]

CFDS are in favour of brighter stright lights? I knew they were in favour of more directional lighting, but not lighting up our streets like daylight. Why can't councils use orange LEDs? There must be a road safety argument here as drivers will lose night vision.

[rabbithutch]

This has been a very interesting thread. As I posted earlier, I am very much in favor of better management of light pollution. I would even like to see (shudder) better case law defining, ceding, and protecting one's right to be free of light pollution. There are specifically defined terms that describe how light pollutes, but I can find very little information regarding the protection an individual might expect or demand from it.

I've done some googling on the subject of light pollution. There are organizations who are lobbying to get better laws, but much remains to be done. Here in Texas, several of the small towns around the McDonald Observatory in the Davis Mountains are passing laws that control pollution and protect the night sky for the observatory. The same is happening very near Houston (4th largest US city) in Fort Bend County to protect the George Observatory. Little, however, is being done to provide a basis for protecting the rights of individuals vis a vis other individuals. Until my generation, this was not an issue because illumination was not as economical nor was the planet so crowded.

Put me in the camp that believes that good lighting must also mean light that doesn't unnecessarily pollute. I'm thinking of joining the Intenational Dark-Sky Association and becoming active at the state and local level. I think that there is much to be done to even raise awareness of the issue much less to educate others. Far too many of our neighbors, are unconcerned but if made aware might be allies.

FWIW