This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here because the All LED Lighting site has gone dark. This material is Copyright 2013-2015 by UBM Americas.

2013-12-05

A Snapshot of LED A-Bulbs

The DOE's latest snapshot report on A-lamps highlights a continuing rise in efficacy, but color quality lags: of 312 listed A-lamps, only four have a CRI above 90.

The US Department of Energy releases snapshot reports approximately quarterly, focusing on one or another subset of the products listed in the LED Lighting Facts program. The latest six-page report centers on omnidirectional LED A-lamps and compares various aspects to the larger population of Lighting Facts-listed lamps and luminaires.


Color Rendering Index and Coordinated Color Temperature of products listed in the DOE's Lighting Facts program.

Most of the products listed in Lighting Facts satisfy both the existing Energy Star efficacy criteria and the tougher requirements that will come into effect in 2014.

The report is dense with facts that will delight the lighting nerds (and statistics nerds) among us. Here's a sampling:

As we might expect, lower-efficacy, probably older, products are being taken off the market, as indicated by the higher average efficacy of currently listed products vs. all that have ever been listed.

The DOE report notes that while omnidirectional A-lamps make up a small proportion of all listed lamps -- around 10%, vs. 60% for directional lamps -- they represent the most visible segment of LED lighting for the general public. Most consumers will have their first experience with LED lighting by the medium of an A-lamp.

Efficacy first, quality sometime
It is no secret that most of the LED lighting supply chain concentrates on squeezing the most light out of the least input energy. A high quality of light is pursued mostly by niche players. Only four of the 312 A-lamps now listed in Lighting Facts render color in a way close to that of an incandescent or halogen, with a CRI above 90.

The report notes that the California Energy Commission's voluntary Quality Lighting Specification, to come into effect in January, should result in more products with higher-quality color rendering showing up on the list. In fact the authors of the federal report sound much like the Californians behind the voluntary spec, pointing out that while a CRI of 80 is comparable to that of a compact fluorescent, that fact is hardly a recommendation considering the market backlash against CFLs on the grounds of poor color rendering.

While some may have a problem with government mandating a lower bound of CRI, which inevitably trades off with efficacy, I hope and believe that the California standard (voluntary as it is) will result in a wider range of choices in the market.

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