Lighting the Future

Cool. I hate changing light bulbs, so I love the fact that LEDs are becoming more efficient and effective...

If a time traveler from a hundred years ago were to visit a home today, much of the technology would be completely alien. The television, cordless phone and computer would probably leave him flabbergasted. But on seeing a light bulb, he might say, "Ah! Here's something I recognize. A few of those grace my home, too."

If the visitor comes back in 15 years, the fruit of Thomas Edison's bright idea may be gone. The likely replacement: light-emitting diodes, or LEDs.

LED lamps were unthinkable until the technology cleared a major hurdle just a dozen years ago. Since then, LEDs have evolved quickly and are being adapted for many uses, including pool illumination and reading lights, as evidenced at the Lightfair trade show here this week.

More widespread use could lead to big energy savings and a minor revolution in the way we think about lighting.

LEDs have been around since the 60s, but have mostly been relegated to showing the time in an alarm clock or the battery level of a video camera.

They haven't been used as sources of illumination because they, for a long time, could not produce white light — only red, green and yellow. Nichia Chemical of Japan changed that in 1993 when it started producing blue LEDs, which combined with red and green produce white light, opening up a whole new field for the technology.

...Just this week, researchers at the Lighting Research Center at Rensselaer Polytechnic Institute in Troy, N.Y., said they had boosted the light output per watt of a white LED to almost six times that of an incandescent light bulb, beating even a compact fluorescent bulb in efficiency.

...But development is brisk, and the Department of Energy has estimated that LED lighting could cut national energy consumption for lighting by 29 percent by 2025. The total savings on U.S. household electric bills until then would be $125 billion.

LEDs have other advantages that are propelling them into niche uses, despite their upfront cost.

Current white LEDs will last up to 50,000 hours, about 50 times as long as a 60-watt bulb. That's almost six years if they're on constantly.

A decade ago, I might not have heard about this idea unless my newspaper (or a big newpspaer like the New York Times or Washington Post) or one of the big three networks talked about it. Technology changed that. Now it will change the light I use to read this information.