By Roland PiquepailleThe holiday season is coming, and you've probably already bought some lights and decorations for your Christmas tree, your house or even your street. But did you know that the market for light bulbs is a $12 to $15 billion one? Now, several companies making light-emitting diodes (LEDs) want a piece of this market, claiming that LEDs are more efficient than light bulbs and could save a staggering $17 billion a year in energy costs. In "Switching off bulbs for LEDs," the San Jose Mercury News reports that in ten years, you'll go to your Wal-Mart store to buy LEDs instead of light bulbs, thanks to fantastic improvements in performance by the LED industry. And did you know that each decade since the first LED appeared in 1962, prices have fallen by a factor of 10 while performance has grown by a factor of 20? In the world of LED engineers, this is known as Haitz's Law, named after retired Agilent scientist Roland Haitz. Read more...
Here are the opening paragraphs of the Mercury News article.
How many engineers does it take to permanently unscrew a light bulb? At San Jose's Lumileds Lighting, the answer is hundreds.
Lumileds, a joint venture of Agilent and Philips Electronics, makes semiconductor chips known as light-emitting diodes. LEDs are found everywhere, from the tiny flashes on digital cameras to the blue lights that illuminate the Arc d' Triomphe in Paris at night. And if all goes right, Lumileds will one day see its LEDs replace the common light bulb.
Federal studies estimate that replacing light bulbs with white LEDs could save $17 billion a year in energy costs, or the equivalent of 30 power plants. That could reduce emissions of carbon dioxide by 155 million tons annually.
LEDs consume less power, don't use harmful pollutants such as mercury and last 10 times longer than conventional lights. They cost more at the outset, but over time they save money in electrical bills and maintenance.
I'm sure you're a bit skeptical here. But as you can see below, this technology can be used in extremely different environments. Both images come from this image gallery.
|Here is a very efficient Amish buggy lamp. "Conventional system required recharging of 60 lb battery after 6 hours of operation. With Luxeon, battery stays charged up to 100 hours." (Credit: Lumileds).|
|And here is a very different environment, a night-club in the Netherlands. "High Power Luxeon LEDs are used for a dance floor subject to shock and vibration, which is very damaging to conventional light sources." (Credit: Lumileds).|
The article then describes the history of the LED industry in a very informative way, including the extraordinary gains in performance during the last 40 years.
Each decade, LED prices have fallen by a factor of 10 while performance has grown by a factor of 20. This phenomenon, known as Haitz's Law after former Agilent scientist Roland Haitz, is the LED equivalent of Moore's Law in the chip industry, which holds that chip performance doubles every 18 months.
|Here is a diagram showing the Haitz's Law for LED flux. LED flux per package has doubled every 18
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