The Department of Energy's CALiPER studies comparing the performance of solid-state lighting products with that of the incumbent technologies they seek to replace continue to track the steady improvement of LED lighting. In its most recent CALiPER Snapshot report, researchers looked at LED outdoor area lighting (including applications such as parking garage lighting that may not be strictly outdoors) in comparison with the already fairly efficient predecessors, high-pressure sodium and metal halide. This being one of the most active application areas for retrofits over the past few years, the DOE's report on the products in its Lighting Facts database is important to everyone in the lighting business.
DOE says the outdoor area lighting category dominates its Lighting Facts database - 23% of the lighting products listed come under this category - and found continued steady advances in the technology and some truly impressive performance at the high end, but suggested that wide variation in product performance should make specifiers wary.
The DOE researchers found that efficacy of outdoor solid-state lighting continues to improve, with mean efficacies for the four product categories - area/roadway luminaires, parking garage luminaires, canopy luminaires and directional luminaires - between 81 lumens per Watt (lm/W) and 91 lm/W and some products posting efficacies as high as 150 lm/W. Correlated color temperature (CCT) on the other hand is actually coming down across the outdoor area lighting category, except in directional luminaires where it continues to increase.
"While many early LED area lighting products were 5000 K or higher, there has been a measurable shift toward 4000 K products, and there is now a wide range of products at different CCTs from which specifiers can choose," DOE said.
Here's the snapshot report (PDF): CALiPER Snapshot Outdoor Area Lighting