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| Can
a New Lightbulb Save the Environment? |
Posted:
06.13.05 | |
| There
may be a bright idea in the ongoing effort to balance America's consumption of
energy with the need to protect the environment -- a better light bulb. Printer-friendly
versions:PDF | |
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| In
the U.S., light bulbs account for one quarter of all electricity used, but waste
nearly half their energy. But recent scientific breakthroughs in light-emitting
diodes could reduce national energy consumption by 29 percent by 2025 for a total
savings of $125 billion, according to the Department of Energy. | |
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| Light-emitting
diodes | |
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| Light-emitting diodes
or LEDs are semiconductor materials, such as arsenic, gallium and nitrogen, that
emit light when an electrical current flows through them. LEDs have the
potential to be significantly more energy efficient than the commonly-used incandescent
light bulb, in which a wire enclosed in a glass bulb gives off light through heat
generated by an electric current.  While
incandescent light bulbs use 95 percent of their energy to generate heat and 5
percent for light, LEDs could use nearly 100 percent of their electricity to directly
create light, consuming significantly less energy.
Incandescent light bulbs
typically last 850 hours, although long-life bulbs can last up to 2,500 hours.
LEDs vary in life, but some white LEDs can last up to 50,000 hours or nearly six
years of constant use. | |
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| Scientific
breakthroughs | |
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| Red,
yellow, and green LEDs have been in use since the 1960s. The color depends on
the type of material used. At first they were used to light-up the numbers
on digital clocks, but now you can find them in some cell phones, car dashboards
and large stadium screens. In 1993, a Japanese company produced the first
blue LEDs, which produced white light when mixed with red and green LEDs. This
breakthrough set off a wave of research and improvement in white LEDs -- which
could be used in homes and offices.  However,
the light produced by most white LEDs can make skin look sickly and are not as
pleasing to the eye as that of incandescent lighting.
But researchers in
the U.S., Europe, and Asia, realizing the power and potential of light-emitting
diodes, are determined to continue improving LEDs. Advances in LED technology
could lead to a whole new concept of home and office lighting -- without light
bulbs. "It's not going to just change the light bulb; it will change
the lighting paradigm," Arpad Bergh of the Optoelectronics Industry Development
Association told the Technology Review. General Electric (GE) has said it
is close to introducing a white LED device that would use half to one-third the
energy of an average incandescent bulb and last six times as long. But
LEDs are not the only game in town in the race to change the light bulb. Organic
light-emitting diodes, which diffuse a patch of light instead of a bright point
of light, could lead to light sheeting on walls, ceilings, curtains, and even
furniture. | |
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| Widespread
use | |
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| LEDs
are already becoming more common in some places, such as traffic lights. According
to research firm Strategies Unlimited, 39 percent of all red lights and 29 percent
of all green lights use  LEDs.
Bright white LEDs can be found in many flashlights and hiking lamps and
LEDs light the rotunda of the Jefferson Memorial in Washington, DC. But
despite their energy efficiency and electricity savings potential, white LEDs
have not yet gained popularity in mainstream markets. At around $20 an installation,
the $0.75 incandescent bulb still has the market cornered. The challenge
now facing researchers is to bring quality up and price down. | |
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| Environmental
impacts | |
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| The
growing use of a better bulb is just one part of a national effort to conserve
energy and prioritize its use. The Alliance to Save Energy found that since 1973
energy efficiency technologies and conservation efforts have led to a 40 percent
cut in the amount of energy consumed in the U.S.  Despite
these efforts to use energy more efficiently, environmental activists are still
concerned about how that energy is made. Over 70 percent of the electricity in
the U.S. is still generated by burning fossil fuels such as oil, gas, and coal.
Burning fossil fuels results in the emission of carbon dioxide, causing
global warming and rising sea levels. When coal is burned, it can lead to acid
rain, which kills fish and trees. "If we don't curtail our energy use,
we could face higher prices if not running out of fossil fuels," said Ronnie
Kweller of the Alliance to Save Energy. "We can't stay on this path of ever
increasing energy use and air pollution. It's just not a sustainable approach."
--
Monica Villavicencio, Online NewsHour | |
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Like many Californians, I live in a town where teenagers drive to school in gas-guzzling SUVs and pick-up trucks just because they want to look powerful and extravagant.
