back to article 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 …


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  1. Richard Eustace
    Thumb Down

    4 x $100,000 = $630,000?

    "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."

  2. Red Bren

    What about light pollution?

    What colour will they be and will they be better shielded to prevent light shining uselessly upwards?

    Lets hope this is the end for the hateful orange glow of the sodium lamp!

  3. Anonymous Coward
    Thumb Up

    good move

    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.

  4. Pooper Scooper

    Sweet...darker skies too maybe?

    Since LED light is more directed and focused than normal light bulbs (subject of course to whatever reflectors are used), perhaps this will lead to darker skies as well for those cities that make the switch. Seeing the stars again would be so nice...

  5. Anonymous Coward
    Thumb Down


    400 cars. That many. More than likely negated within a month.

    Why not just turn the lights off.

  6. John Savard

    One Downside

    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.

  7. This post has been deleted by its author

  8. Timbo
    Thumb Up

    Been there, done that...!

    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 as to set an example...

  9. Xpositor

    Think of all the pretty colours (sorry, colors)

    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...

  10. Graham Bartlett


    Richard, I suspect the formulae look more like:

    cost of replacing entire city's LEDS = $630k

    (cost of replacing half of your sodium lights + cost of running sodium lights per year) - (cost of replacing one-sixth of city's LEDs + cost of running LEDs per year) = $100k

  11. Edward Rose

    Good on 'em

    Nice to see it.

    Reduced 'lit' times would be good too.


    The old lights weren't free.

  12. Tom

    LED Street lights

    At least for Toronto they are talking about traffic lights at intersections (The Red-Stop, Green-Go, Amber-go-like-hell things) not the white general illumination, I don't think LED is ready for that yet! (still use stuff like HP Sodium for that).

  13. Mark

    RE 4 x $100,000 = $630,000?

    Guess some of the extra might be made up in the fact that over the 4 years they are not ging to have to do 2 bulb replacements on the standar streetlamps.

  14. N1AK

    It helps to be right.

    @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.

  15. Anonymous Coward

    Re: 4 x $100,000 = $630,000?

    Perhaps they did their calculations using Excel 2007.

    IGMC ...

  16. Haku

    "Intelligent lights" ?

    The move is a good one but as someone else posted, why not turn them off? or how about this, a sensing network that only turns them on when someone is nearby?

  17. Anonymous Coward


    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.

  18. Stephen

    RE: 4 x $100,000 = $630,000?

    The $100,000 is only the energy savings, it doesn't include money saved for having to change the lamps less often, less maintainence, etc

  19. Anonymous Coward

    Sensing Network

    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...

  20. Anonymous Coward
    Thumb Up

    Sensing network

    I like the idea, be like MJ in the Billie-Jean video (or was it beat It?)

  21. Dave

    Is it? Could it be?

    The government is doing something productive! Holy shit!

  22. Richard Eustace

    Yeah Ok

    But it looks like smoke and mirrors to me

  23. Darren Sandford
    Dead Vulture

    Turn them on only where needed

    Gah! Imagine trying to get to sleep when the streetlamps outside your window keep going on and off...

  24. breakfast Silver badge
    Thumb Up

    @Sensing Network

    Surely the lights switching on would be a pretty good indicator that those muggers were coming out of concealment?

  25. Glen Turner


    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.

  26. Morely Dotes
    Thumb Up

    @ Timbo

    "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.

  27. maajka
    Thumb Up

    Not bad


    I actually live in Ann Arbor but I didn't know about this.

    At least something good from Michigan...

  28. Kevin McMurtrie Silver badge

    Oh sure, the warranty is good!

    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!

  29. Phil Endecott

    Are LEDs really more efficient than fluorescent?

    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.

  30. Daniel

    Re: Sensing Network

    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.


  31. Harris Upham


    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.

  32. Anonymous Coward

    ?Use Rechargable batteries & Solar Cells?

    I don't see why they can't install Rechargable Head Units with Solar Cells

    The ones in my garden have been running for 3 years, Nothing ever needs

    doing to them.

    Then it really would be eco friendly

  33. Mark Roome

    Poor salmon

    I hope they are up to it.

    Non-LED Flashing coat thanks.

  34. Ring peanut gallery

    Yes, there are big pollution savings from their longer life and their lower power use but...

    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.

  35. Anonymous Coward

    Re: Oh sure, the warranty is good!

    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.

  36. Anonymous Coward
    Anonymous Coward

    even Toronto?

    "...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?

  37. Jon Tocker

    sounds like some people are being stiffed

    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.

  38. Eleanor Rigby
    Thumb Up

    @ Darren Sandford

    you, Sir, are this thread's resident Genius.

  39. Andrew Norton

    traffic light problem

    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.

  40. Carl
    Thumb Down

    Maybe more efficient for signal lights but not street lights

    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.

  41. TeeCee Gold badge

    @Darren Sandford

    "Imagine trying to get to sleep when the streetlamps outside your window keep going on and off..."

    It'll be curtains for you then.

    (Sod the coat, give me my running shoes)

  42. Ken Hagan Gold badge

    Only temporarily green

    The real WTF here is that an electric light has a carbon footprint. As and when this scandal is tackled, the green credentials of these new lights will be much reduced.

  43. Phil Endecott

    @Kevin McMurtrie

    > 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.

  44. Andy Crofts

    @ Darren Sandford

    "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.....


  45. Andy Crofts

    @ Darren Sandford

    "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.....


  46. salman ali
    Thumb Up

    re: 4 x $100,000 = $630,000?

    They said the LEDs last 10 years instead of 2. Presumably replacing the bulbs twice, with the manpower and replacements and transport involved costs the extra 230,000.

  47. Anonymous Coward
    Anonymous Coward


    If LED lighting was already that good I'd be able to light my rooms at home with them. As it is I can't even find a retailer willing to rate the light from an LED light source in terms of incandescent bulb equivalent power. Speaks volumes for the usefulness of today's LED lights.

  48. Steve Roper

    LEDs and CFLs

    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...

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