By Craig DiLouie, LC, CLCP
The outdoor stationary lighting sector has been a leading market for LED lighting. In September 2017, the DOE’s CALiPER program released an updated snapshot of the state of the art in LED outdoor area lighting, focusing on luminaires and luminaire retrofit kits. The report analyzed the some-16,000 products (12,000 area/roadway and 4,000 other products including parking garage and canopy luminaires) listed in the Lighting Facts database. Outdoor area lighting makes up about 26 percent of all products listed in Lighting Facts.
LED outdoor area products are available as energy-saving replacements of 70W, 100W, 150W, 250W, 400W, and 1,000W high-pressure sodium (HPS) luminaires. At any given light output up to the equivalent of a 1,000W HPS luminaire (about 100,000 lumens), LED outdoor area products are available with substantially higher efficacy (lumens/W) than their traditional counterparts.
Due to the broad range of outdoor area lighting applications, the range in efficacy and output among listed products was very wide, from less than 70 to more than 150 lumens/W, and from less than 500 to more than 125,000 lumens. Since the last CALiPER Snapshot in September 2016, average outdoor area product efficacy increased by about 9 lumens/W, while average correlated color temperature (CCT) decreased. Nearly two-thirds (63 percent) of the listed products satisfied the efficacy and output specifications for the DesignLights Consortium’s Qualified Products List, with 25 percent reaching the higher efficacy and output level required to achieve Premium listing.
Efficacy gains are being achieved primarily through improvements in light output, as average input power remained relatively steady during the previous three years. Parking garage luminaires were an exception, with higher light output achieved by increasing input power. Canopy luminaires were another, with light output remaining somewhat constant during the previous five years, with efficacy gains achieved mainly through reduced input power.
A majority of products had a color rendering index (CRI) rating in the 70s, which is fitting for many outdoor area applications. Many outdoor area luminaires were available with a CRI in the 80s, however, particularly among listed parking garage and canopy luminaires. Average CCT has been decreasing, part of a continuing shift in outdoor area lighting. The median CCT among listed products was about 4100K, about 1000K lower than it was six years earlier.
Depending on the luminaire category, 41 percent to 49 percent of listed products had a CCT of 5000K or higher. Between 29 percent and 38 percent had a CCT of 4000K. Meanwhile, 17 percent of area/roadway, 8 percent of parking garage, and 16 percent of canopy luminaires had a warm CCT of 3000K or lower, with each of these three values higher than in the September 2016 Snapshot Report. Nearly all listed outdoor area products satisfied the DesignLights Consortium’s CRI and CCT requirements for QPL listing.
The September 2017 Snapshot Report can be downloaded at http://bit.ly/2BhM5xa.
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DiLouie, LC, principal of Zing Communications (zinginc.com), is a lighting industry journalist, analyst, marketing consultant, and author. Reach him at cdilouie@zinginc.com.