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Spring 2002 Issue |
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| Striking a balance between energy and the environment in the Columbia River Basin |
ArticlesEnergy Trust will pursue conservation, renewables in Oregon Council decisions for 2001 and 2002 Council seeking comment on Fifth Power Plan Self-powered: is distributed generation in our energy future? Federal agencies propose to boost spending on salmon recovery Conservation investments today could moderate economic impacts of volatile power prices tomorrow John Hines appointed new Montana Council member Success stories: Pend Oreille River |
Illuminating Changes: New Technology in LightingOne way we responded to last year's energy crunch was by exchanging our incandescent light bulbs for more energy efficient compact fluorescent bulbs. But there is another kind of light technology that has also been receiving some attention lately. Light-emitting diodes, or LEDs, have been used for a number of years as indicator lights in applications like stop lights on automobiles, traffic lights and exit signs. In fact, about 80 percent of exit signs being sold today use LEDs as the primary light source. This represents a significant increase in efficiency since, according to the USEPA Energy Star program, LEDs use 2 - 5 watts of electricity compared to 20 - 40 watts for incandescent and 12 - 24 watts for compact fluorescent bulbs. They are also used in large neon billboards and on giant display screens.
LEDs are solid-state semiconductor devices that convert electrical energy directly into light. Unlike incandescent bulbs, they have no filament and produce no heat. They cannot be damaged by shattering or breaking. Their light generating components are encapsulated in solid epoxy. Because of this, they are extremely durable and long lasting. And they use only about one-tenth the electricity of incandescent bulbs. This past Christmas, the tree at the state Capitol in Salem, Oregon was decorated with strings of LEDs donated by Portland General Electric, another advance in the use of these lights. What has limited their growth for general lighting purposes thus far has been the inability of manufacturers to produce a white LED product comparable to incandescent or fluorescent lights. LEDs are currently available in red, amber, green and blue. But their promise is alluring: According to research professor Hongxing Jiang at Kansas State University, if all household lights could be replaced by white LEDs, about $100 billion in energy costs a year could be saved worldwide, in addition to significant decreases in pollution and heat.
A recent development toward products sometimes referred to as "the new LEDs" are organic light-emitting diodes, or OLEDs. These new lights are made from plastics and other organic molecules, and have the potential to supplant the use of LEDs in display lighting, since they can be more efficient and provide sharper definition. One big drawback, however, is their short life span?only about 10,000 hours compared to 100,000 for LEDs. Still, there is considerable optimism about advancements in both technologies. And prospects on how such "solid-state lighting" might be used are intriguing. Researchers at the National Research Council in Ottawa, Canada are looking into portable computer screens that could be printed on a plastic sheet instead of a glass base. Imagine folding up your laptop like a newspaper when you want to store it discreetly away, or using a "wearable micro display" placed in your eyeglasses that would show an image comparable to viewing a 21-inch screen. Now that's a really portable computer! |
Council decisionsNov 2001 Dec 2001 Jan 2002 Feb 2002 Mar 2002
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