| August
1,
2006
Green
Connections: Leading the Way to Better Lighting
by Barbara Quinn
Burned
out incandescent bulbs in the Castaic Lake Pressure Control Structure
weren’t just a nuisance for the Metropolitan Water District, which
is responsible for the California Aqueduct that transports water from
the Sacramento-area Oroville Dam to some 17 million people in Southern
California. Operators needed dependable light to operate machinery and
process controls – and with up to a third of the facility’s
500 incandescent lamps down at any one time, they weren’t getting
it.
The district chose LED (light-emitting diode) lamps from LEDtronics
as an alternative to its traditional incandescent lighting system. The
advantages of the lamps were compelling: a 100,000-hour lamp life, sharply
reduced energy use and virtually no labor expenses for system maintenance
or bulb replacement. Simple replacement of the incandescent bulbs with
LED lamps eliminated retrofitting costs. And, by preventing the disposal
of thousands of burnt-out incandescent lights, the LEDs eliminated a
significant source of pollution.
The Technology
LED technology has evolved substantially in only a few
years. At its most basic, an LED is a semiconductor diode chip mounted
the reflector
cup of a lead frame. The frame is connected to electrical wires and encased
in a solid epoxy lens. Light is emitted when energy levels change in
the semiconductor diode. Unlike incandescent bulbs, which give off the
full spectrum of light in a spherical pattern, LEDs emit a focused beam
of a single wavelength at a variety of angles but in only one direction.
Early LEDs were limited to marginal
uses, such as switch illuminators, but the technology’s range of uses changed when multi-chip arrays
and high-flux LED chips were developed. Other technical advances dramatically
increased LED light output. Today’s LEDS can transmit both visible
and infrared wavelengths, with colored light determined exclusively by
the semiconductor compound used to make the LED chip.
An LED produces no heat and is virtually
impervious to shock, vibration and temperature extremes, making them
almost indestructible.
Also worth
noting, LEDs don’t burst; when they need replacement, their light
gradually fades, allowing time for replacement.
Expanding applications Although not yet optimal for all applications,
such as general lighting, LED technology incorporates unique characteristics
that have made it the preferred choice for some uses.
For example, a doctor with the Royal Danish Air Force
burned his hand on a hot halogen bulb that promptly burned out when a
swing-arm task
light above the examination table in a medevac helicopter made the light
fixture too hot to reposition. The Danish Air Material Command immediately
sought an alternative that would provide the necessary light without
the accompanying heat. LEDtronics supplied a direct incandescent replacement
that conformed to the standard European E27 socket, allowing a simple
swap-out of lamps.
In another application, blue LED lights now illuminate the Vincent Thomas
Bridge in Los Angeles. The mile-long span features 80 lamps, each one
containing 360 LEDs but using only 19.5 watts of power to produce light
equivalent to a 150-watt incandescent bulb. To offset energy costs yet
further, 4.5 kW solar panels, located near the bridge, generate electricity,
which is sold to the Los Angeles Department of Water and Power.
Total lifetime costs for LED lighting
compare well to incandescents needed for the same time period. For
the bridge, lifespan savings are
estimated to be $688,400, with energy savings alone of $184,000. Initial
LED lamp costs have shaken more than one potential buyer. LEDtronics
website features an interactive program that produces a direct comparison
between incandescent and LED lamps for individual projects.
Founded in 1983, LEDtronics® leads where others only
follow when it comes to designing, manufacturing and packaging state-of-the-art
LEDs to meet the world’s constantly changing lighting needs. Our
inventive product line encompasses an array of direct incandescent lamp
replacement Based LEDs, low-cost snap-in and re-lampable Panel Mount
LEDs, high intensity sunlight-visible Discrete LEDs, PCB LEDs circuit
board status indicators, surface mount diodes SMT LEDs, full-spectrum
rainbow RGB LEDs, Ultraviolet (UV) and Infra-Red (IR) LEDs.
For
additional information, contact LEDtronics toll free at 1-800-579-4875,
telephone 310-534-1505, fax at 310-534-1424, e-mail webmaster@ledtronics.com or mail at LEDtronics Inc., 23105 Kashiwa Court, Torrance, CA 90505.
Visit our website at www.ledtronics.com.
Link to:Pollution Engineering
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