Republication of Postings from the U.S. Department of Energy (DOE) Solid-State Lighting Program
by Jim Brodrick, U.S. Department of Energy
If you attended LIGHTFAIR International last week in Las Vegas, we hope you got a chance to stop by DOE’s booth and catch our SSL educational presentations that played to SRO crowds throughout the show. In between those presentations, the various members of our SSL team found time to walk the show floor, and we thought we’d share our observations with you in this week’s Posting.
Whereas the emphasis at LIGHTFAIRs past seemed to be on LED replacement lamps, this year replacement lamps — albeit plentiful in number — were mostly in the background, with the accent shifted to newer form factors such as pendant-style and flush-mount, in some cases involving flexible materials. That trend could indicate the beginning of the real SSL revolution, as manufacturers start to think “outside the bulb” in earnest. It might also reflect the fact that comparable LED lamps are being offered by a wide range of companies, to the point where customers have become comfortable with, and even used to, those products.
Speaking of form factors, this year’s LIGHTFAIR sent a signal that “thin is in,” with a number of edge-lit LED luminaires spearheading a perceptible movement away from the deeper, heavier, “clunkier” look — a development that will eventually have a significant impact on how buildings are built and how lighting is deployed. While there were some edge-lit products at last year’s show, this year there were far more, and they looked and performed better.
It’s also evident that manufacturers are becoming increasingly attuned and responsive to customer feedback — and that, in addition, they’re starting to focus on putting added value in SSL products. One example that reflects both trends is the move toward higher color quality, which — for replacement lamps — has largely been driven by California’s codes. Many brands displayed at LIGHTFAIR offered 95-CRI options for new and retrofit lamps, usually with CCTs of 2700K and 3000K, and there were numerous products where the manufacturers had “played with the recipe” to achieve better color quality — e.g., by biasing the product below the black body curve and aiming for a wider color gamut. Several displays featured the ability of specially tuned LED lights to make white materials and surfaces appear brighter and whiter. We also saw many LED lighting products that were color-tunable, enabling the user to change the spectral content, with some purporting to affect mood, health, and productivity as well as aesthetics.
There seems to be increased awareness of flicker issues, and a determination to fix them with better drivers and improved dimmer design. And significant gains in efficacy may be just around the corner, as we saw some demos (lamp and luminaire) that were in the neighborhood of 200 lm/W.
Another thing we couldn’t help but notice at this year’s LIGHTFAIR was that controls were everywhere. It seemed as though almost every booth had a control system to demonstrate, and although standards for controls are still lacking, a lot more functions are now being offered — such as tiered capabilities that can encompass individuals, small groups, multiple groups, or integrated building systems, all tied together with networked communication. New developments in sensor technology are leading to an increase in the intelligence of these systems, some of which even offer video capture, real-time analysis, and the use of frequency-modulated light for wireless location tracking of shoppers in retail stores. And in some cases the integration of sensors and communications chips into the luminaire itself is leading to hands-free self-commissioning of installations to meet all required codes.
As for OLEDs, they’re looking better than ever as they move closer to being ready for prime time. But there’s still a lack of commercial products — although those we did see at LIGHTFAIR displayed a good deal of novelty (e.g., transparency, tunability, flexibility). Some of the design concepts based on thin sheets of light, which had been introduced by OLED luminaire manufacturers, are being adopted by LED manufacturers using edge-lit systems — which at first glance might seem to be alarming news to OLED manufacturers but is actually encouraging, not only because it confirms that those designs are desirable and worth pursuing, but also because they’re best-suited to the unique strengths and advantages of OLED technology.
While the progress SSL has made is impressive, it’s far from being “game over.” The technology still has a ways to go to achieve its full potential, and there are a number of issues yet to be addressed. But having seen LIGHTFAIR 2014, we can’t help feeling encouraged — and filled with the feeling that the best is yet to come.
