Magical Mystery Devices or Not: How Do LED Lamps and Luminaires Really Measure-Up?

Panel: Market Transformation: Taking Efficiency Mainstream

Authors:
Mia Paget, Pacific Northwest National Laboratory
Jeff McCullough, Pacific Northwest National Laboratory
Heidi Steward, Pacific Northwest National Laboratory

Abstract

Solid-state lighting products for general lighting applications are now gaining a market presence, and more and more people are asking, "Which of these are ‘good' products? Do they perform as claimed? How do they compare? Light Emitting Diodes (LEDs) differ from other light sources enough to require new procedures for measuring their performance and comparing to other lighting options, so both manufacturers and buyers are facing a learning curve. The energy-efficiency community has traditionally compared light sources based on system efficacy: rated lamp lumens divided by power into the system. This doesn't work for LEDs because there are no standard LED "lamp" packages and no lamp ratings, and because LED performance depends heavily on thermal, electrical, and optical design of complete lighting unit or ‘luminaire'. Luminaire efficacy is the preferred metric for LEDs because it measures the net light output from the luminaire divided by power into the system.

There is a great deal of conflicting and erroneous information being propagated today about the actual performance of LED luminaires. This paper will provide readers with:

• An understanding of luminaire efficacy and why it is useful and necessary.

• Results from CALiPER testing of SSL luminaires and replacement lamps.

• How this applies under the ENERGY STAR® criteria for solid-state lighting.