For all the buzz over compact fluorescents, the low-wattage bulbs are, in all likelihood, a stopgap solution. The real action is in light-emitting diodes (LEDs), although consumers will be waiting several years before they see anything reasonably priced on store shelves.
We get occasional inquiries about LEDs, and this recent article in the San Diego Union Tribune provides as good an excuse as any to write about them. Like CFLs, LEDs sip electricity — they’re about 80% more efficient than standard incandescents, and both their energy profile and color has been improving by leaps and bounds in recent years. Unlike CFLs, they contain no mercury.
Now, the mercury issue for CFLs is a bit overblown. Coal-fired power plants are the single biggest source of mercury emissions in the U.S., which means that incandescent light bulbs are the worst offenders on the mercury front, by virtue of their higher energy consumption.
Nevertheless, LEDs are the hands-down winner on this score. Other things in LEDs’ favor: they are dimmable, they turn on immediately, they offer a better quality of light, and they last up to five times longer than CFLs.
LEDs are also tiny and lightweight, making them suitable to a range of new lighting applications. Indeed, the best known consumer application of LEDs as a source of illumination (rather than as electronics displays) is in flashlights.
And now the major downside: LEDs presently cost about $50 per bulb (insofar as a “bulb” is really the right way to think about a semi-conductor light source). Because of their longevity, they actually make financial sense even at this price, but only for commercial applications in which maintenance costs are high relative to material costs. That’s why you see so many LEDs in traffic lights. And also why LEDs will soon be illuminating the top of the Empire State Building, which currently requires a team of six to change the colors on its exterior spotlights.
How long until LEDs become ubiquitous? Experts caution we should give them another five to ten years before prices come down to mass market levels and remaining technical kinks are worked out.