By Michael F. Carmichael
Nov. 3, 2011
Not only are your streetlights going green by way of LEDs (Light Emitting Diodes), but they’re getting smarter than most of us. They’re dimming when their “normal” light isn’t needed – like residential areas after the 11 p.m. news – and they can show first responders to the house that called 911 among a whole host of other talents.
| Crawford Lipsey, CEO of Relume Technologies. |
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Crawford Lipsey is CEO of Relume Technologies, the company leading the way for municipalities to go green while saving their taxpayers significant money. He says that the company name is pronounced “ree-lume” – as in “re-luminate.” Therein lies just one of the ways municipalities across the country are switching to talented and money-saving LED streetlights. The new lights can use the existing poles and wiring, saving on installation.
But, why are LED streetlights just now becoming popular? “It was really a breakthrough in technology,” explains Lipsey. “The company started back in 1999 and stayed small for a very long time. Peter Hochstein, the founder who passed away this past May, was with the ‘Black Ops Group’ at General Motors Corp. He was a pioneer in what’s called thermal management.
One of Hochstein’s projects involved a way in which the vehicles in a military convoy could communicate “from taillight to headlight,” Lipsey says. “Because convoys were moving a lot at night, under radio silence – they certainly didn’t want lights on, so they had infrared lighting via LED lights that provided communications from the lead vehicle to those behind. A lot of the time convoys traveling at night in the desert would get lost. If the convoy is a mile or two in length and one guy takes a wrong turn… . So the infrared LEDs would allow them to communicate safely.”
“LEDs [for commercial use] didn’t really become popular because the light wasn’t that good,” Lipsey continues. “It produced very low lumens per watt and just wasn’t that efficient. The enemy of LEDs is heat.” Hochstein effectively solved both issues – the volume of light LEDs could produce as well as how to dissipate the heat.
| Downtown Ann Arbor, Mich. lighted by LEDs. |
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With those problems solved, cities across the country are turning to Relume and other manufacturers – primarily because they can save precious budget dollars. “We’re saving upward of 60 percent on their energy costs for an installation in Ann Arbor, Mich.,” says Lipsey proudly. “Depending on the cost per kilowatt hour, the payback can be as little as three years. So energy savings is first and foremost.”
“Second,” he continues, “is maintenance. Our fixtures can last anywhere between 70,000 and 100,000 hours. That’s considerable compared with the traditional streetlight, which has a life of between 15,000 and 24,000 hours. It’s expensive to go out with bucket trucks and shut down streets to re-lamp the fixtures so maintenance is the second largest driver to go with LEDs.”
Lipsey says that yet another advantage of LEDs is their ability to provide a variety of light “looks” that results from the color temperature of the LEDs themselves as measured in degrees Kelvin. Unlike compact fluorescent lights that are making their way into commercial and residential use – and which were initially panned because of their “colder” blue-white light – LEDs can be almost any color of white from warm (actually fewer degrees Kelvin) to a light closer to daylight (which is in the higher Kelvin range.) “Things appear to be brighter, with less light,” with LEDs, says Lipsey.