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New York City Street Lights To Go LED

Posted by Soulskill on from the big-apple-lite dept.

eldavojohn writes "Wired has a short piece on NYC's new street light project. I don't think we need to belabor the many benefits that LEDs hold over traditional light bulbs, but the finishing touches are being addressed, and they will hopefully be put into place sometime next year. This design won a competition back in 2004, and OVI has been whittling down the prototypes. At $1.175 million, this sounds like a pretty cheap deal considering the DOE forked over $21 million to 13 R&D projects along the same lines."

5 of 303 comments (clear)

  1. flicker crashes by goombah99 · · Score: 4, Interesting

    The thing that is awful about led lamps is that most of them are run straight off the AC voltage and have massive 100% brightness flickers. If you are moving it's like a strobe. You don't see it in car lights since they are run off DC. but most, perhaps not all, AC socket lamps I've seen have really bad flicker.

    I also how they have secondary lenses since LED's can be very directional the way they are typically resin cast.

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    Some drink at the fountain of knowledge. Others just gargle.
    1. Re:flicker crashes by digitalunity · · Score: 4, Interesting

      Assuming the line voltage is run through a full wave bridge rectifier, there would be a 120 Hz flicker, imperceptible to most people. Toss a large capacitor across that DC output and you've got dramatically less ripple.

      Your directionality comment is apropos. It's also worth noting that some people don't like the light spectrum output on white LED's. Personally, I prefer the pink tint from high pressure sodium lamps.

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      You can't legislate goodness. Let each to his own destiny, by will of his freely made choices.
    2. Re:flicker crashes by zenyu · · Score: 4, Interesting

      *sigh* You remind me of the EE graduate student who was showing me and my classmates around his lab one day. To prove the point that humans couldn't hear a 16kHz tone very well he quickly turned the power up from 1 to 11, and through pain practically paralyzed the half of the class that still had their hearing intact.

      Many cars have the flickering tail LED lights, and it has nothing to do with DC-DC converters or other sources of ripple in the supply current. It's simply a matter of the duty cycle timer, the tail lights are "dimmed" not by limiting the current but by turning them completely on and off at a low frequency. The ones I've seen are in the 40-80Hz range, just stick an oscilloscope on there if you don't believe me. The flicker stops when the lights go to full illumination (i.e. the break petal is depressed).

      Now go outside and look at some LED tail lights! Even if you have very poor vision you should be able to see the ones flickering at 40-50 Hz.

      PS If you are legally blind, just don't comment on lighting. You are bound to suffer from foot in mouth at times; go take on those annoying audiophiles buying 1000 euro power chords.

  2. Re:Giant LED light bulbs by dgatwood · · Score: 4, Interesting

    Yeah. I've noticed that. What I don't get is why they choose to set the color temperature that way. Red LEDs are extremely cheap compared with producing light at the other end of the spectrum. Why in the world would they balance them towards the blue (expensive) end of the spectrum when that is both more expensive and visually unpleasant? About the only thing I can imagine about the current LED designs is that they were designed to be used in combination with standard incandescent bulbs. If you blend the two, you should get a fairly nice looking light spectrum, albeit probably a bit heavy in the yellows....

    I'd buy LED lights instantly if they actually used three emitters. Unfortunately, most don't. They use two---one yellow, one blue. Because the yellow LED has a relatively narrow light spectrum compared with an incandescent, you end up with basically no light output down near the bottom of the visual spectrum. The result is light that is downright unpleasant to deal with in every way. The bluish light makes it hard to see color accurately, makes colors not reproduce well in photography or video, and really isn't good for you mood-wise. Basically, the current crop of LED lights have all the problems of CFLs except the mercury (well, and the LEDs should last a lot longer, I believe).

    The question, then, becomes this: "When are we going to see properly designed white LED bulbs?"

    On the other hand, while they suck for homes, the existing LED lights are perfect for street lights. First, there was one experiment that suggests that suicides and crime may decrease when street lights are replaced with bluish lighting. Second, the color temperature of blue LEDs are virtually indistinguishable from the mercury vapor lights (~6000K) that are already used in a lot of places.

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  3. Bad plan in snowy environment... by Anonymous Coward · · Score: 5, Interesting

    Here in Portland, OR, we have already started to use LED street lights. And now that we're in a snow storm, these lights aren't working. LEDs don't produce heat (that's why they're efficient). By not producing heat, they don't melt the snow away from them. So all the LED streetlights in Portland are covered in snow and cannot be seen.

    The old lights produce enough heat to melt all the snow. Snow in Portland is rare, so it's not that big of a deal. In NY, it's quite the opposite.