Switching to LED lighting

PANAMA. A new lighting technology is sweeping across the world, spreading from the Buckingham Palace to street lights in the United States for their ability to reduce energy consumption and carbon dioxide emissions.

To change the bulbs in the 60-foot-high ceiling lights of the Palace’s grand stairwell, the New York Times reports, workers had to erect scaffolding and cover precious portraits of royal forebears.

A lighting designer proposed light emitting diodes or LEDs two years ago as a lighting solution for the home of ardent environmentalist British Prince Charles.

The new lights, the designer said, would last more than 22 years and enormously reduce energy consumption and carbon dioxide emissions. Since then, the palace has installed the lighting in chandeliers and on the exterior, where illuminating the entire facade uses less electricity than running an electric teakettle.

With this shift, the palace is part of a small but fast-growing trend of replacing energy-wasting disposable bulbs with more efficient (albeit more expensive) ones.

LED lighting was once relegated to basketball scoreboards, cell phone 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. It is often considered the prime candidate to replace inefficient incandescent bulbs.

As the lights move indoors, they could have an enormous effect on climate change. About 20 percent of carbon dioxide emissions associated with buildings in the United States and the United Kingdom are related to indoor lighting.

Studies also suggest that a complete conversion to LED lights could decrease carbon dioxide emissions from electric power use for lighting by up to 50 percent in just over 20 years.

Yet significant barriers remain for widespread use by homeowners.

First, there’s the high initial cost. According to the New York Times, lighting experts believe investments in LED lighting would take five to 10 years to recoup in electricity savings.

An outdoor LED spotlight today costs $100, as opposed to $7 for a regular bulb.

Second, 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.

A third disadvantage of LED lighting is that they could provide a pleasing warm light or be energy-efficient, not be both at the same time.

Yet nearly monthly scientific advances are addressing many of these 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.

For example, in May two small companies showed off a LED lamp at the Light Fair trade show in New York that’s both very power-efficient and produces a light similar to that of a standard tungsten or halogen bulb.

The LEDs in the lamp shine through a thin layer of "quantum dots," a scattering of particles of very small but precisely controlled size. When light hits them, they emit light of a different color, much like the "phosphor" layer of a fluorescent tube.

The magic of quantum dots is that the color they emit can be controlled very accurately by adjusting their size, which means less wasted energy and more pleasing color.

The more pleasing light produced by quantum dots could allow LEDs to outshine 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.

Buckingham Palace might not be the average home, yet some of the lights in homes and particularly those in offices and big stores can already be replaced by LEDs.

And with a technology that changes every month, it’s only a matter of time before environmentally-friendly LEDs can be used in all lights.