Advancing the effective use of light for society and the environment.

Friday, January 16, 2004

LRC’s ASSIST program pushes adoption of LED technology and standards

A high power white LED.

Since its inception in 2002, the Alliance for Solid-State Illumination Systems and Technologies (ASSIST) has been active in a number of research projects and other activities to advance and promote LED technology.

“The major goal of the ASSIST program has been to facilitate broad adoption of reliable, energy-efficient LED technology by original equipment manufacturers and specifiers,” said N. Narendran, Ph.D., director of research and head of the solid-state lighting program at the LRC. Research, education, and industry collaboration have been the key activities of the program, which seeks to reduce many of the technical hurdles standing between LEDs and market acceptance.

LED technology has made a number of inroads in the last few years, particularly with improvements in luminous efficacy (now greater than 20 lumens per watt for white light) and light output per LED. New applications also are being found in signage, automotive, aviation and mobile phone industries.

ASSIST has been actively working on projects and issues that benefit the entire industry, said Narendran, including:

• An ASSIST-sponsored study showed that the color rendering index (CRI) metric did not correlate well with people’s preference for the color of an illuminated space. Read more about this study.

• One of the biggest complaints about white LEDs is the perceivable color differences between similar LEDs. How much color variation can there be between similar LEDs is a common question. ASSIST asked LRC researchers to conduct a laboratory study to develop color tolerance criteria for white LEDs. A report is in progress.

• Boeing, along with other ASSIST sponsors, launched a study at the LRC to evaluate aircraft reading light specifications and identify preferences for light levels, color properties, and beam patterns. A report is in progress.

• A new ASSIST-sponsored study now under way seeks to identify applications of LED lighting systems that are beneficial to older adults in assisted-living facilities. LRC staff will evaluate lighting solutions with LEDs in patient bedrooms and in common areas.

Industry activities to promote consistency, standards

Beyond technical research, ASSIST has been active in fostering discussions between traditional luminaire manufacturers and LED manufacturers. At the end of March, staff from the LRC’s Solid-State Lighting Program plans to host a roundtable discussion between ASSIST sponsors and other LED and LED system manufacturers to present the first of a series of recommendations for the use of LED light sources and systems. The first “ASSIST Recommends” document offers a definition for the useful life of LEDs, based upon life tests conducted at the LRC and information found in literature regarding noticeable light level changes.

“The purpose of ‘ASSIST Recommends’ is to help manufacturers present information to end users in a consistent manner,” said Narendran. Future recommendations are planned for white LED color tolerance and requirements for LED-based reflector lamps.

Other industry activities have included educational workshops, writing a guide for specifiers about the strengths and weaknesses of LED systems, and developing an applications requirement document to help LED manufacturers target niche lighting applications.

Benefits to sponsors

Narendran noted that sponsors of ASSIST are benefiting in a number of ways from their affiliation with the Solid-State Lighting Program. Sponsor companies are taking advantage of opportunities to leverage funding to expand the use of LED lighting products, showcase products at the LRC and in field studies, have free registration privileges on all LRC solid-state lighting educational programs, network with other ASSIST members and contact LRC staff and faculty for advice, and provide input on target activities.

For more information, visit the ASSIST Web site.

About the LRC

The Lighting Research Center (LRC) is part of Rensselaer Polytechnic Institute and is the leading university-based research center devoted to lighting. Founded in 1988, the Lighting Research Center has built an international reputation as a trusted and reliable source for objective information about lighting technologies, applications, and products. Its mission is to advance the effective use of light and create a positive legacy of change for society and the environment

© 2004 Rensselaer Polytechnic Institute, Troy, NY 12180 USA.

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