North American cities go green with LED traffic lights
- Thread starter Paul_in_Maryland
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VanIsleDSM
Enlightened
North American? maybe American.. most of the traffic lights I saw in Toronto were all LED.
And absolutely all of them are LED here on the west coast. All the crosswalk sings too.. everything is LED here in traffic.
I imagine the more socially advanced US cites have mostly LED though.. I'd be willing to bed Seattle and San Fran have lots of LED traffic lights.
And absolutely all of them are LED here on the west coast. All the crosswalk sings too.. everything is LED here in traffic.
I imagine the more socially advanced US cites have mostly LED though.. I'd be willing to bed Seattle and San Fran have lots of LED traffic lights.
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jtr1962
Flashaholic
Actually the article said LED streetlights. Traffic lights have been going LED for quite some time. Only a few localities are trying LED streetlights. I look forward to the day we're rid of those crappy orange sodium lights. Besides making the nighttime world look ugly, they make driving more dangerous due to the loss of peripheral vision.
Once the fixture and ballast losses are accounted for, even a 75 lm/W LED is more than competitive with sodium vapor on an efficiency basis. Initial cost is the main reason LEDs haven't yet been widely used in this application. The steep improvement curve may have something to do with it also. It would be embarrassing to municipalities to spend millions setting up LED streetlights, only to have ones which are twice as efficient available two years later.
Once the fixture and ballast losses are accounted for, even a 75 lm/W LED is more than competitive with sodium vapor on an efficiency basis. Initial cost is the main reason LEDs haven't yet been widely used in this application. The steep improvement curve may have something to do with it also. It would be embarrassing to municipalities to spend millions setting up LED streetlights, only to have ones which are twice as efficient available two years later.
VanIsleDSM
Enlightened
oh I see... I was wondering there.. I thought that was already quite common...
75lm/w ? only if they're using ancient magnetic ballasts.. power must be regulated before driving LEDs aswell.. and the power loss there and the power loss in an electric ballast aren't too far off... sodium is still more efficient for now.. but the lifetime of the LEDs makes them attractive replacements as they're lm/w increase.. I'm all for getting rid of the orange light though.
75lm/w ? only if they're using ancient magnetic ballasts.. power must be regulated before driving LEDs aswell.. and the power loss there and the power loss in an electric ballast aren't too far off... sodium is still more efficient for now.. but the lifetime of the LEDs makes them attractive replacements as they're lm/w increase.. I'm all for getting rid of the orange light though.
LEDninja
Flashlight Enthusiast
The article refer to Toronto.
Toronto has only a few streets switched over.
The major expected savings is cost of relamping,rather than the savings in the electric bill.
The new improved models every 2 months is driving the managers nuts.
Links:
http://www.candlepowerforums.com/vb/showthread.php?t=156708
http://www.candlepowerforums.com/vb/showthread.php?t=169530
http://www.candlepowerforums.com/vb/showthread.php?t=170136
Hanilton just replaced all the downtown LED crosswalk LED signal lights all at once. I guess it is cheaper to do this than one at a time. Most of the old ones still have reasonable brightness.
Toronto has only a few streets switched over.
The major expected savings is cost of relamping,rather than the savings in the electric bill.
The new improved models every 2 months is driving the managers nuts.
Links:
http://www.candlepowerforums.com/vb/showthread.php?t=156708
http://www.candlepowerforums.com/vb/showthread.php?t=169530
http://www.candlepowerforums.com/vb/showthread.php?t=170136
Hanilton just replaced all the downtown LED crosswalk LED signal lights all at once. I guess it is cheaper to do this than one at a time. Most of the old ones still have reasonable brightness.
made in china
Newly Enlightened
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- Sep 30, 2007
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Traffic departments get the power for their traffic signals from local power companies, usually. Since the traffic signals feed directly off of mains lines without a meter, the power company relies on the Traffic department to report how much power is being used. Traffic Signal Electricians will measure the current draw at an intersection and record it. This data is compiled and reported to the power company so billing may be done. It is in the Traffic dept's best interest to swap in as many LED indications at a location as possible so they can do a follow up power consumption audit and get maximum benefits.
