The Latest in LEDs

According to Permlight in Tustin, Calif., the portion of the illumination market that currently uses light-emitting diodes (LEDs) as its main light source is now $8 to $10 billion. This includes LEDs used in cell phone and PDA displays, indicator lights, signage, traffic signals, lasers and general illumination applications.

Advancements and improvements

One of the areas that LEDs have seen advancements in recently has been in the improvement of thermal management. “By using thermal conducting materials that divert generated heat away from the diodes, the devices run cooler and brighter,” said Manuel Lynch, Permlight’s CEO. Cooler-running LEDs require less maintenance and are even longer lived.

Another area of advancement has been in the development of blue LEDs, which offer improved color rendition and require lower voltage levels to operate. Using nanotechnology, manufacturers such as Kopin Corp., Taunton, Mass., can create pockets in the semiconductors that allow blue LED chips to produce light at levels under 2.9V.

“The latest blue LEDs are brighter than before, offer better color rendition, and are becoming more affordable and more widespread,” observed John Fan, Kopin CEO.

Besides blue LEDs, the industry is also seeing the development of white-light LEDs, which produce a bright light at levels exceeding 100 lumens.

“The efficiency of these new white LEDs is better than both incandescent and halogen light sources at around 30 lumens per watt,” said Rebecca Bompiedi, vice president of technology for GELcore, LLC, a joint venture of GE Lighting. White LEDs can be used in a variety of non-general illumination applications, such as in cell phone and PDA displays, and it is the advent of brighter white LEDs that is creating a new market for the technology in general illumination applications.

“While the high brightness LED market grew 50 percent in 2002, the market for white LEDs in handheld devices is growing at a consistent annual rate of 100 percent,” Bompiedi reported.

This phenomenal growth of LEDs in the handheld/mobile device market can be attributed to the advent of white light. “For example, it is white LEDs that enable the new colored screens on cell phones.”

GELcore is also heavily researching combining ultraviolet-emitting semiconductors with red, blue and green phosphers to create the appearance of white light that will mimic fluorescent light technology.

“The product should be introduced to the market in two to three years. These LEDs will be almost as efficient as compact fluorescent lamp (CFL) technology in light output, but will be longer lived and will require less maintenance,” Bompiedi said.

LEDs offer users low energy consumption, long life, low maintenance, excellent color rendition and reduced heat generation. In addition, they are smaller than other traditional light sources, the generated light is not dispersed, they can be controlled with optics for a use in a wide array of applications, and their solid-state nature makes them more rugged.

Of course, nothing’s perfect. “LEDs’ light output is not as bright as other sources for general illumination applications,” admitted Bompiedi.

Other shortcomings include higher up-front cost, lower efficiency than modern fluorescent lighting, and the need to further improve LEDs’ color rendition.

What contractors need to know

Since lighting is a large part of an electrical contractor’s job, a general understanding of LEDs is essential for contractors to be able to educate the end user about the benefits of the technology. “As they improve, LEDs will be used in more and more applications, and electrical contractors need to research the technology today and understand the direction the devices are taking,” advised Fan.

“Electrical contractors need to remember that LEDs are classified as low-voltage devices, they are DC-driven, their smaller profile requires different fixture solutions, and they are generally easier to handle and safer to install than traditional lighting sources,” said Bompiedi.

In addition, LEDs’ low-voltage classification means that they do not require ground fault circuit interrupters (GFCIs).

One of the benefits to electrical contractors of promoting the advancement of LEDs is a larger margin. “LED lighting systems are easier and faster to install than traditional sources, allowing the contractor to increase its bottom line,” observed Lynch.

LEDs also enable the contractor to offer more innovative and creative lighting solutions to their customers.

“Promoting LEDs is an opportunity for electrical contractors to offer energy-efficient lighting solutions that require low maintenance to customers, and to proactively work with specifiers to include LEDs in the project’s design, especially in those applications where saturated colors are required,” concluded Bompiedi. EC

BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 or