2011年3月15日 星期二

LED bulbs future shine

Incandescents going dark; CFL, LED bulbs future shine


Largely unchanged for a century, Thomas Edison's incandescent bulb with its glowing strand of tungsten will soon be a thing of the past.

Manufacturing of the bulbs will be banned, gradually, starting in 2012 with the high-wattage 100-watt bulbs. The 75-watt bulb will follow in 2013, then the 60- and 40-watt in 2013.

While compact florescent light, CFL, has been around for more than a decade, electric device manufacturers and energy conservation specialists are scrambling to educate consumers on purchasing both CFL bulbs and a new generation of halogen incandescent or cutting-edge LED bulbs.

Shopping for light bulbs used to come down to one number: Watts.

With the growing prominence of the energy-saving compact florescent bulbs and the scheduled incandescent phase out, other numbers come into play -lumens and kelvins.

CFLs cost more than three or four times incandescent bulbs. But an average CFL bulb can save the user between $30 and $60 through its lifetime. A wholesale switch to CFL bulbs could have a huge impact. A study by Phillips Lighting estimates there are 4.4 billion household lighting fixtures in the U.S. If they were all swapped for other more efficient bulbs, Americans would save $15.8 billion in energy bills, about $200 per household.

"We know upfront costs are an issue, but new light bulbs will more than pay for themselves," said Ronnie Kweller, spokesperson for the Alliance to Save Energy, an Washington D.C.-based energy independence organization. "Consumer have choice and savings out there."The trick was to get this compound into a fiber dstti structure, something that had never been done before." Using an innovative high-pressure chemical-deposition technique developed by Justin Sparks, a graduate student in the Department of Chemistry, Badding and his team deposited zinc selenide waveguiding cores inside of silica glass capillaries to form the new class of optical fibers."

In addition to the savings, there are environmental benefits. According to the U.S. Energy Star Program, if every household added just one CFL, it would result in an equivalent reduction in greenhouse gases as removing 800,000 cars from the road.

Despite the savings and environmental benefits, some people just don't like the traits of CFL bulbs. People accustomed to the instant-on of incandescent lights didn't like waiting, even for a few seconds, for a CFL bulb to power up to full illumination. First-generation CFL bulbs and many cheaper ones being sold now, have a cooler, blue light compared to the warm yellow light of incandescents.

Since those days, manufacturers have addressed the CFL bulbs warm-up time, and now market some bulbs as "instant on." The once-blue light cast by CFL bulbs that made everyone look pale and even ill, has warmed up a bit.

Joshua Mast, co-owner from the Colonnade event space in Scranton, said first-generation of CFL bulbs that cast a sickly blue light highlighted imperfections. CFL bulbs warmed up through the years, casting a warmer light more flattering on the human form. The Colonnade switched to warm CFL bulbs, and a combination of natural light and incandescents in chandeliers, had the right mix, Mr. Mast said.

"The CFLs are available in different color ranges and you want the warmest light you can for living or entertaining," he said.Corrine Grimley Evans, a spokesman for the Oxford Pedestrians cfl bulbs Association, said the county council's plans for a redesign involving roundabouts would improve life for those on foot. "Soft white or blue light is good for some work and public spaces, but doesn't make people look very good."

New numbers

How do you tell warm light from cool light? Kelvins, or a number followed by a "K." Kelvin numbers around 2,700 is the closest to an incandescent bulb. Lumens measure the brightness, or light output of a bulb. The most efficient bulbs will have more lumens relative to lower wattage.

A 100-watt incandescent bulb, for example, would produce about 1,600 lumens. A 60-watt bulb, about half as much. But there's enough of a range to make comparison shopping worthwhile.

Mercury scare

Small amounts of mercury are used in the manufacturing of CFL bulbs. Each contain between 4 and 5 milligrams - enough to fill the period at the end of this sentence. So long as the bulb is intact, the mercury poses no threat.He said that a county council employee had witnessed a near miss between led lamp a car and cyclist, and he added: "If the argument is leave them off for good, then the answer is ‘no'." When a bulb breaks, experts recommend opening windows, gently sweeping up the parts remains, and keeping young children away. The potential risks, however, aren't worth avoiding the new technology, said Ms. Kweller.

"We understand concerns about mercury, but people are only exposed if the bulb breaks and the amount is one one-hundredth what you would find in an old-fashioned thermometer," she said.

Mercury concerns may also be a thing of the past, as even more efficient and longer-lasting light-emitting diode, or LED, bulbs come on the market. Ms. Kweller said the amount of mercury used in the manufacture of CFL bulbs is declining, as well. But CFL bulbs may already be approaching obsolescence.

Dim prospects

Dimmable light fixtures are efficient, allowing the user to cut down the energy, and the lighting, to whatever is necessary. People with dimmable fixtures are finding that they don't work with most CFL bulbs. Even "dimmable" CFL bulbs, which cost $10 or more each, often don't work properly, said Don Fisch showroom manager for Friedman Electric in Scranton.

"They are getting better, but they still don't work the way that people are accustomed to," Mr.CALLS have been made to turn off the lights at one of led lighting Oxford's busiest junctions, after the traffic ran more smoothly when they failed. Fisch said.

Halogen lights, an adaptation of incandescent technology, are dimmable and use less energy.

Tight squeeze

As a walk down any lighting aisle will show, lights are not one size fits all. CFL bulbs have been getting smaller, and some are in a bulb-like casing so that they look like conventional bulbs.

If the light fixture looks like a tight fixture, look for a light that is a "mini" or "micro-mini."

"The first CFLs were big, but now they have a range of sizes and styles that change almost daily," said Mr. Fisch.

CFL bridge?

Some are calling CFL bulbs a "bridge technology" to super-efficient LED bulbs. Upon commercial release, an LED 100-watt equivalent costs more than $50. Mr. Fisch said they sold, and continue to sell, a fair amount of them as a 20- to 30-year replacement in hard-to-reach places such as cathedral ceilings. He think LED bulbs are the future of home lighting, using one-tenth the electricity of a incandescent.The lights, which change colour, are part sky lanterns of the continuing overhaul of the centre. Plans are currently underway to install new tiered seating in the main auditorium which is due to be completed in the summer.  

LED bulb prices are coming down, said Joe Mezlo, manager of energy efficiency programs for PPL Electric Utilities. Bulbs that were $50 are already down to $35 to $40, he said.

"With competition and improved production, LED lights will come down in price just like flat-screen televisions and VCRs," Mr. Mezlo said.

In the context of a home or kitchen remodel, Ms. Kweller said spending $30 to $50 on LED bulbs that will outlive the cabinets would be a sound investment.

Far from lamenting the demise of his invention, Mr. Edison would be proud, said Maria MacDonald, director of interior architecture program at Marywood University.

"Edison was an inventor who never stopped trying new things. He worked to evolve and perfect technologies," she said. "He would proud of us, that we haven't stopped learning and are moving forward."

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