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History of Light (& Heat)

The history of man-made light is based on heat. Wax, oil and gas burn to produce light. The filament in an incandescent bulb heats up to produce light. Gas in a fluorescent tube is zapped to illuminate. The basic method is "Heat it up, and it glows."

For more than 120 years, incandescent light bulbs have brightened and literally warmed our lives. Electric-powered bulbs were a major improvement over candle, gas and oil light sources, but they are extremely inefficient. Bulb-based light sources are far better at producing heat than light – up to 90 percent of the power going into a bulb is converted to heat.

Compact fluorescent bulbs (CFLs) are more efficient, and are an excellent alternative to incandescent bulbs for Edison-socket light fixtures. However, they contain a small amount of mercury, making them hazardous waste when they break or burn out.

In the past 12 months, a new light source has emerged that is sufficiently bright and efficient to be used for general illumination. The light emitting diode, commonly called the LED, uses far less energy and can last many times longer than most bulbs and contains no lead or mercury. Cree, Inc. introduced the first commercially available lighting-class LED in late 2006. Lighting manufacturers are now producing a whole new class of LED lighting products for general illumination.

LEDs are now ready for broad deployment across general lighting applications such as parking garages and lots, streetlights and other outdoor installations. Indoor directional and down light solutions are also becoming available. According to the University of California, Santa Barbara, widespread deployment of LED-based lighting could save $280B in electricity costs in the U.S. alone by 2025.

By committing to LEDs in municipal lighting, cities are making a thoughtful energy choice that will greatly benefit their taxpayers, visitors and the environment.

Related posts:

  1. LED is coming
  2. LED change the world
  3. LED Light Knowledge-What consumers should know about Solid State Lighting for general lighting applications?
  4. LED History
  5. Comparison of different general illumination light sources

This entry was posted on Thursday, November 27th, 2008 at 12:05 am and is filed under LED History. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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