LEDs (Light-Emitting Diodes) are changing the paradigm on the streets – literally, with new applications in municipal lighting, as well as with growing usage on vehicles.
With their small size, energy-efficient and low-temperature light output, LEDs have become the favored source for lighting in computers and other electronic applications. Now they are being increasingly used in total vehicle lighting and municipal street lighting.
LEDs on Cars - from Back to Front
In the automotive industry, LEDs were earlier applied in, and have since become the primary choice, for CHMSLs (Center High-Mounted Stop Lamps) – due to their small size, ability to be packaged in small spaces, high efficiency/low heat light output, and longer life (up to 10X, resulting in little/no need to replace them in locations difficult to access).
Recently, LEDs have been growing in usage in other automotive lighting applications worldwide – particularly in rear lamps, allowing new design freedom, as well as vehicle differentiation (you may have noticed their faster "on" speed and higher visibility in brake lights). They are now increasingly being used in virtually all automotive signal lighting, including stop/tail, backup, rear fog, mirror-and front-mounted turn lamps, as well as interior lighting.
With the development of white LEDs, forward lighting applications were inevitable. On its new R8, Audi seems to be the first to use LEDs extensively in headlamps, for the low and high beams, as well as the front turn signals and DRLs (Daytime Running Lights) – all contributing to the unique appearance of the vehicle.
(click on picture at left to see animation - source: AL Lighting)
Lexus is also using LED headlamps on its flagship LS600h projector design, and Cadillac has announced use of complete (high & low beams, turn indicators) LED-powered front units on its 2008 Escalade Platinum Edition.
LED Street Lighting in Ann Arbor (read on)
Ann Arbor Leads the Way with LED Street Lights
Here in Ann Arbor (which we residents like to think of as an innovative place to live & work), the city is leading the way with LED usage in street lighting, and the national media is recognizing the innovation.
In a recent Wall Street Journal article entitled " Nine Cities, Nine Ideas - Local governments around the globe are coming up with some of the most innovative ways to cut energy use. There are lessons here for places of all sizes." (February 11, 2008, page R1), Jim Carlton writes:
Officials in this town of 115,000 near Detroit took a close look at their $5 million-a-year municipal electrical bill two years ago and realized they were shelling out $1.5 million -- or roughly a third of the total -- just for street lights. Then they realized they could save substantially by simply swapping standard bulbs for a newer technology: light-emitting diodes, or LEDs.
Unlike standard lights that use heated, incandescent bulbs, LED light is cooler and is produced by a semiconductor. The bulbs last as long as 10 years, or five times longer than traditional lights, while using about half as much energy, Ann Arbor officials say.
The LED technology has been around for decades, and the lights have become common in computer indicators and traffic lights. But until about two years ago, LEDs weren't practical for street-lighting purposes because it was difficult for them to produce white light, says Govi Rao, chairman of Lighting Science Group Corp., a New York-based LED provider.
In 2005, Ann Arbor tried out one technique for making white light: blending red, green and blue beams. City officials installed some of the makeshift lights in the City Hall parking lot. "They looked like they were cobbled in somebody's garage," recalls David Konkle, energy coordinator for the city.
Then manufacturers came to the rescue, developing aesthetically pleasing white bulbs by coating blue LEDs with phosphor. City officials spent $15,000 to install the new lights on a few streets downtown and in a residential neighborhood.
One of the few complaints was from a resident who said the new lighting no longer illuminated his home on the street; LEDs shine light directionally and are typically pointed down at the ground, unlike incandescent bulbs, which cast a glow all around. "We told him we're not in the business of lighting his home," Mr. Konkle says.
Most other people liked the new LEDs, and the city recently obtained a $630,000 grant from the Ann Arbor Downtown Development Authority to replace all 1,046 of the street lights downtown. The city estimates that replacing the downtown street lights alone will save more than $100,000 in reduced power costs annually as well as 294 tons of carbon-dioxide emissions -- equivalent to the carbon dioxide that about 35 homes generate annually from electricity use.
After that, Mr. Konkle says, the rest of the city's lights will be replaced as the technology develops and prices drop. City officials say they could cut their light bill by as much as $700,000 a year by replacing all of the 7,000 or so streetlights in town.
A Paradigm Shift in Two Major Areas of Lighting
These two examples of innovation (categorized as "radical" or "nonlinear", as defined by a new replacement of existing, e.g., incandescent technology) will likely continue to grow – changing the paradigm in their application areas. Major drivers for this change include the increasing worldwide awareness of the need to reduce energy and costs, as well as the other benefits of LEDs to the automotive and other industries. Providers of LED lighting & accompanying electronics will grow, thrive and prosper. Those lighting suppliers who have not already added LEDs to their portfolio and remain tied to incandescent and related technologies will likely not. As was the case in earlier paradigm shifts (such as the change in automotive forward lighting from standard-sized, glass sealed beam incandescent headlamps to today's vehicle-specific plastic units with replaceable bulbs), cars – and now street lights – will likely increasingly move to LED light sources. Innovation is inevitable.
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