Let 2020 launch the quality-of-light era for LEDs and SSL (MAGAZINE)

Jan. 29, 2020
MAURY WRIGHT calls on the solid-state lighting industry to dedicate itself to product development focused on longevity, reliability, and appropriate color quality, or quantifiable usable light, for the intended application henceforth.

For the past few years, I’ve written and spoken about what I perceive as our LED and solid-state lighting (SSL) industries evolving into an era where we focus on quality of light. Over the past decade, the industry worked hard in finding a way to replace nearly every legacy light source with LEDs. The focus was clear — energy savings, which was a noble goal. But often the industry has just replaced one bad light source with another, such as fluorescent T8s and T5s replaced by LED tubes or TLEDs. Such business has consumed a lot of commodity LEDs. But it hasn’t created great profit margins, it hasn’t improved our lives tremendously, and it’s left the LED and SSL sectors seeking a new direction. Quality should be that direction, but what does that mean?

Now before we attack the subject of quality, I must make some concessions. There have been some incredible innovations at the component and fixture level in the past decade, especially the last five years. Products represented in our Sapphire Awards offer great examples. But there remain plenty of bad lighting installations.

One angle is longevity and reliability. We have a great article on those concerns, written by Alex Baker of the Illuminating Engineering Society (IES). It’s too bad rampant specsmanship continues to plague the industry. The next round of IES standards will help that situation, as Baker describes.

Still, it’s time to take a step back from most energy-focused metrics that have ruled the SSL space. I’ve been told you can’t have it both ways many times. But I do support the efficacy regulation for lamps that the Trump administration is trying to eliminate. Generally, with luminaires, we need more application-focused metrics that can in some way imply quality.

We know that better color rendering requires more red energy in the spectral power distribution, which equates to higher cost and less energy efficiency. LED efficiency continues to ramp slowly, so trading some energy savings for quality must be fair. Ultimately, the issue runs from the entire supply chain to regulators. We need a common language and policy for guidance.

I don’t have the answer. Using my article about our HortiCann Light + Tech event last fall, I can give an easy-to-understand example. The horticultural lighting industry has worked feverishly the last several years, and the sector now has metrics that are far better than those designed for humans. But as one of the speakers for a lighting manufacturer focused on the cannabis market said, the metric that really matters is pounds per square feet of growing space. I think energy or costs still must figure in, but you get the idea. Tie the metric to the desired outcome.

This is not a new concept. The first time I interviewed Mark Rea of the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute back in 2013, he was espousing application metrics and continues to do so.

The problem is the complexity of considering so many applications. We need ideas that can be generalized somewhat. Color rendering is important, although it should be fair to still put a light with bad color rendering in a basement closet. But for instance, if the notion proves true that some infrared (IR) energy in our everyday lighting is a good thing, we can’t have metrics that penalize a source or product with some IR energy in the spectral power distribution. I hope to discuss this conundrum with many of you in the coming months.

Maury Wright,


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