To change the bulbs in the 60-foot-high ceiling lights
of Buckingham Palace’s grand stairwell, workers had to
erect scaffolding and cover precious portraits of royal
forebears.
In shifting to LED lighting,
the palace is part of a small but fast-growing trend that
is redefining the century-old conception of lighting,
replacing energy-wasting disposable bulbs with efficient
fixtures that are often semi-permanent, like those used in
plumbing.
Studies suggest that a complete conversion to the lights
could decrease carbon dioxide emissions from electric power
use for lighting by up to 50 percent in just over 20 years;
in the United States, lighting accounts for about 6 percent
of all energy use. A recent report by McKinsey &
Company cited conversion to LED lighting as potentially the
most cost effective of a number of simple approaches to
tackling global warming using existing technology.
LED lighting was once relegated to basketball
scoreboards, cellphone consoles, traffic lights and colored
Christmas lights. But as a result of rapid developments in
the technology, it is now poised to become common on
streets and in buildings, as well as in homes and offices.
Some American cities, including Ann
Arbor, Michigan., and Raleigh,
N.C., are using the lights to illuminate streets
and parking garages, and dozens more are exploring the
technology. And the lighting now adorns the conference
rooms and bars of some Renaissance hotels, a corridor in
the Pentagon and a new green building at Stanford.
LEDs are more than twice as efficient as compact
fluorescent bulbs, currently the standard for greener
lighting. Unlike compact fluorescents, LEDs turn on quickly
and are compatible with dimmer switches. And while
fluorescent bulbs contain mercury, which requires special
disposal, LED bulbs contain no toxic elements, and last so
long that disposal is not much of an issue.
“It is fit-and-forget-lighting that is essentially there
for as long as you live,” said Colin Humphreys, a
researcher at Cambridge University who works on gallium
nitride LED lights, which now adorn structures in
Britain.
The switch to LEDs is
proceeding far more rapidly than experts had
predicted just two years ago. President Obama’s stimulus
package, which offers money for “green” infrastructure
investment, will accelerate that pace, experts say. San
Jose, Calif., plans to use $2 million in energy-efficiency
grants to install 1,500 LED streetlights.
Thanks in part to the injection of federal cash, sales
of the lights in new “solid state” fixtures — a $297
million industry in 2007 — are likely to become a
near-billion-dollar industry by 2013, said Stephen
Montgomery, director of LED research projects at
Electronicast, a California consultancy. And after years of
resisting what they had dismissed as a fringe technology,
giants like General Electric and Philips have begun making
LEDs.
Though the United States Department of Energy calls LED
“a pivotal emerging technology,” there remain significant
barriers. Homeowners may balk at the high initial cost,
which lighting experts say currently will take 5 to 10
years to recoup in electricity savings. An outdoor LED
spotlight today costs $100, as opposed to $7 for a regular
bulb.
Another issue is that current LEDs generally provide
only “directional light” rather than a 360-degree glow,
meaning they are better suited to downward facing
streetlights and ceiling lights than to many lamp-type
settings.
And in the rush to make cheaper LED lights, poorly made
products could erase the technology’s natural advantage,
experts warn. LEDs are tiny sandwiches of two different
materials that release light as electrons jump from one to
the other. The lights must be carefully designed so heat
does not damage them, reducing their lifespan to months
from decades. And technological advances that receive rave
reviews in a university laboratory may not perform as well
when mass produced for the real world.
Britain’s Low Carbon Trust, an environmental nonprofit
group, has replaced the 12 LED fixtures bought three years
ago for its offices with conventional bulbs, because the
LED lights were not bright enough, said Mischa Hewitt, a
program manager at the trust. But he says he still thinks
the technology is important.
Brian Owen, a contributor to the trade magazine LEDs,
said that while it is good that cities are exploring LED
lighting: “They have to do their due diligence. Rash
decisions can result in disappointment or disaster.”
At the same time, nearly monthly scientific advances are
addressing many of the problems, decreasing the high price
of the bulbs somewhat and improving their ability to
provide normal white light bright enough to illuminate
rooms and streets.
