North American cities go green under LED street lights A city near Detroit is replacing all the bulbs in its street lighting with LEDs, following similar moves by a town in North Carolina and even Toronto. The move will bring in savings of $100,000 per year, Ann Arbour city officials said, meaning the investment will pay itself off inside four years. Mayor John Hieftje told the …
"The move will bring in savings of $100,000 per year, Ann Arbour city officials said, meaning the investment will pay itself off inside four years."
"The project will take two years to complete and is being funded to the tune of $630,000 by the city's Downtown Development Authority."
finally someone realising that all those "standard" energy saving lights are very bad for our health as they contain mercury which usually ends up in our food (through the food chain).
LED lights are the ONLY way to go for energy saving lights, compact flourescent (the standard energy saving bulbs) are way too toxic to be a viable alternative to the good old energy wasting light bulbs.
One example I was able to find of the spectral distribution of light from a white LED light showed a marked peak at around 453nm, but the spectrum was continuous.
This means it won't be easy to filter out, the way light from the previous energy efficiency champ, low-pressure sodium was (it's all in the D line).
Which means more light pollution for amateur astronomers who can't afford to drive into the country to observe.
This post has been deleted by its author
My mum recently received a Council letter telling her that there might be some disruption in Maidstone due to the fact that all the bulbs in the traffic lights were being changed to LED types...again, lower energy consumption and climate change being the main reasons why.
Seems like a good idea to me...just wish other pubic bodies followed suit....and while they are at it....get the councils to turn off their own office lights at night please...so as to set an example...
Imagine, every street light able to be 'tuned' to its own specific colour, or cycled through a rainbow affect - every town could become a work of art, or you could spell the name of the town out for aircraft flying overhead. The colour could be tinged red if traffic is bad, or a slight hint of green if the roads are clear. They could be a lighter colour if somebody is walking nearby, dimming down again to reduce pollution once they have passed by...
I think I'll change my name to Ama Zon and submit a patent application...
@Richard Eustace: They replace the normal bulbs every two years, which means they will be factoring in the cost of two sets of normal bulb replacements into the break even point.
How ever their total savings per year should be $630k * 2.5 / 10 = $157,500 when you factor in the costs of replacing 3 more sets of none energy efficient bulbs.
The difference is probably the expenditure that they would have pumped into replacing the sodium bulbs anyway. If I'm being generous and not assuming that ALL policitos are scheming lying scum. The original 400k will be the saved costs in power and bulb replacements over the four years after installation. The remaining 230k will be the ongoing costs until that point of maintaining the current system.
Yay - a sensing network just like the one in our office. If you sit still for more than 10 minutes or so all the lights go out and you end up jumping up and down, waving your arms about like a mad thing to get them to come back on again.
So lets add the same thing to the street - no standing at bus stops or street corners then.
And those crafty muggers just need to lie in wait for a few minutes until all the street lights turn off and you pass by later thinking the street's deserted...
I'm not so sure that the reduction in maintenance will be as dramatic as expected. They really can't be thinking of not cleaning the light cover for ten years? LEDs are not that bright anyway, without needing to shine through a decade of grime.
One thing which did astonish me when traveling in the USA was the huge amount of illumination of traffic signs, rather than using signs made from reflective materials.
"just wish other pubic bodies followed suit"
Funniest typo all week!
There are a number of places on the Internet where Joe Public can buy LED lighting for the home. The initial high cost of the "bulbs" is offset by much lower energy costs, and much longer bulb life; but it means I can't change over every bulb in my home at one time. I still have 2 to 4 incandescents someplace in the house, and everything else is either flourescent tubes or compact flourescents, so over time I can replace them with LEDs, but since they last so much longer than incandescents (and also cost as much as LEDs), I fear it will be several years before everything is LED.
Also, in the 12 miles between work and home, almost all of the green traffic signals have been converted to LEDs. I would say that about one-third of them are faulty, in that portions of the light are dark, or flicker. This does not inspire confidence in the manufacturer, but at least the light still works even when it's partly faulty, unlike the 100-watt incandescents they have replaced.
The LED traffic lights installed around here were supposed to last a decade. Two years after installation they're flickering and loosing LEDs fast. It looks like water leaks and unfiltered power surges got them.
Let us also not forget the CFLs that we've been told to use. They're efficient and last for 7 years! What percentage of your CFL lamps last longer than 3 months? If the power supply doesn't blow up in the first month the wires usually break loose from thermal stress in the next month. (I'm also guessing that there's a big area of mercury contamination in the hardware store isles where the CFLs of the shelves fall and explode on the ground.)
What are the odds that the new street lamps will actually last 10 years? Sure, the LED elements are rated for 50K - 100K hours but the manufacturer only has to make the lamp boards last long enough to get out of town. Make it cheap!
My recollection was that LEDs and fluorescent about equally efficient, i.e. both much more efficient than incandescent. Maybe technology has moved on since I last saw the numbers. Or, maybe the bulbs that they're replacing actually are incandescent bulbs! I mean, they're replacing them every two years; that doesn't sound like a fluorescent bulb to me.
Have you ever lived near a normal street light that was on the verge of giving up the ghost? They glow, then they come on bright for a while, then they snap off. Then they glow, then they come on bright for a while, then they snap off. It's damn annoying to the local residents. I don't imagine a sensing network would be any better.
Oh, and a big yay! for the LED street lights.
-daniel
New York installed them a couple of years ago, very fast rollout. Street lighting is still sodium-arc, though. Zero dent on light pollution; that's not exactly the point in this town. However, with the sheer quantity of traffic signals and pedestrian signals now sporting LEDs, there's got to be an enormous power savings, maintenance savings and huge kickbacks and political favors for such a large deployment. The icing on the cake- the new signals seem to work just fine.
I just hope that, if Toronto ever does replace the general purpose street lamps, they will put proper reflectors on them.
I don't need my room lit from the street. If I want to see what's going on in my bedroom, I'll light it myself.
Wasted light is a quality of life problem (for me and astronomers alike) and an environmental problem we could so easily fix.
I've been using CFLs in every room for ten years, in that time not a single bulb has failed on me. I did move in that time and I didn't take them with me, so I'm not saying that they lasted ten years, but they've lasted at least five years in each property. My guess is that you picked a bad batch or even more likely, a cheap batch.
As others have noted, across large parts of the UK they've already switched to LEDs for traffic signals. I've yet to see one which has failed, unlike others in this thread.
More interestingly, a quick google search shows that overhead LED street lighting is a reality despite suggestions otherwise. So the article may just refer to sign-lighting and traffic signals, but it's entirely possible that it includes replacement of Sodium lighting too.
"...and even Toronto" - what's that supposed to mean? Anyway, the City of Toronto kept incandescant street lighting until around ten years ago, because no one could stand the orange or pink sick look of the sodium lights used in the suburbs. Finally, when metal halide lamps got affordable and reliable enough, they made the move, and it's been pretty good. Each lamp takes 70 W, and the ballast takes 20 (which could presumably be improved on with modern electronic versions). The old incandescant bulbs were either 300 or 500 W, depending on the size of the street, so there's a pretty good saving. But they did insist on adding more lights (every pole has one now, where before there were often gaps), so the energy saving isn't what it could've been.
I think people are confusing LED street lighting with LED traffic (signal) lights, which are already quite common in Toronto and elsewhere. I don't think LED technology is bright enough for street lighting yet. But then why do we light streets in the first place? Why not light pedestrian areas with low-level, small lights, and leave the cars to fend for themselves, as they do on rural highways?
We've been having incandescent bulbs in traffic lights gradually replaced (all new installs are LED, older units are being replaced on both an as-needed and a scheduled basis.)
The LED lights are visible over better distances and the colour is sharper (especially when the green or red coating in the lens of the incandescent ones starts to age),and seem to be lasting quite well - some of the earlier units have been around for ages and are still running fine.
Could be those who're experiencing problems are encountering ones made to the cheapest possible specs by really shitty manufacturers.
We've got a newish intersection near an old one (they rerouted a few roads a while ago) and when both sets of lights are green during daylight hours I can see the more distant LED lamp more clearly than the old and faded incandescent on - both in amount of illumination (at night the LED is even more obviously brighter than the incandescent) and clarity of colour (vibrant green vs greenish tinge).
The incandescents seem to lack the light output (even with half the colour filter faded away) to be clearly visible during the day while the LEDs are very noticeable.
There is of course one problem that I, as a wearer of glasses with a hefty prescription, has found.
In the UK, with the pole-mounted traffic lights, there is little problem, but US19, just south of Atlanta, for instance, has a bit of a problem when it rains. The greens are very bright (I think Clayton county went for the ultrabrights) and as it's often windy when it rains, the traffic lights on the overhead wires sway back and forth. You can end up being dazzled at night not only by the traffic lights themselves, but by its reflection off the wet road as well. More htan once, I've had to have my wife act as a co-driver, to talk me off the road, having lost a good percentage of my vision do to this.
I'm also trying to think of any road signs around here that are lit up. I don't even think I20 and I75's signs are lit up, unlike the british motorway signs I remember so fondly. Then again, the whole state of Georgia has less electronic traffic signs than the M57.
I'm not sure about the US but in other parts of the world we use low-pressure sodium vapor with up to 200 lumens per watt efficiency. Good white LEDs are only around the 50 lumens per watt and research prototypes only around 100 lumens per watt.
Surely this is a step backwards in terms of efficiency? Sure they may save the cost of replacing the sodium lamps, but I'm not sure its more efficient.
> What percentage of your CFL lamps last longer than 3 months?
100%. I bought my first one in about 1990 and it's still going; most of mine are about 12 years old and in perfect health. I have had only one failure in all that time.
> If the power supply doesn't blow up in the first month the wires
> usually break loose from thermal stress in the next month.
I think you got a bad batch. Did you complain to the retailer?
Back on topic: the more I think about this, the more convinced I am that these people in Ann Arbor are replacing _incandescent_ street lights with LEDs. They probably never adopted the sodium vapour lamps that the rest of the world uses because they don't like the colour. For those of use with sodium vapour street lighting, moving to LEDs would increase energy use.
"Gah! Imagine trying to get to sleep when the streetlamps outside your window keep going on and off..."
Haven't you anything else to do? Getting the 'other half' 'going on and off' a few times a night would want me gettin' some of those lamps.
Maybe because she's Finnish.....
</coat>
"Gah! Imagine trying to get to sleep when the streetlamps outside your window keep going on and off..."
Haven't you anything else to do? Getting the 'other half' 'going on and off' a few times a night would want me gettin' some of those lamps.
Maybe because she's Finnish.....
</coat>
I also use CFLs and swear by them. I've had the same set now for 3 years and they're still as bright as the day I got them, and my electric bill is half what it used to be (as I'm a bugger for leaving lights on).
As to the mercury being a contamination problem: LEDs aren't any better. The photoelectric material they operate on is Gallium Arsenide Phosphate, a rather choice brew to be dropping into landfill once they expire, methinks...
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
