At its June Program Meeting, CEE hosted Brad Koerner, Lighting Market Manager at Color Kinetics. Koerner addressed several myths associated with solid-state lighting (SSL) as part of a general session panel on emerging opportunities.

Before presenting the group with common misconceptions about LED performance, Koerner provided key background information. Generally, SSL technology is divided into two sub-categories: Light Emitting Diodes (LEDs) and Organic Light Emitting Diodes (OLEDs). The presentation focused on LEDs, as they are recognized as being the nearer-term application.

Koerner defined an LED as a small semiconductor diode device that converts electrical energy directly into a discrete color of light. LEDs use different compounds to produce different colors of light, and contrary to popular belief, are not a new technology. The LED was invented in 1962, and the first LEDs emitted a dim, red light. Additional colors emerged over time, with white LEDs coming out only in the late-1990s.

Speaking about the advantages of LEDs, Koerner noted their long life (leading to low maintenance costs) and relatively low power consumption. He also said they can be designed to avoid UV or IR light and that they are easily controllable.

In terms of myths, Koerner spoke about the claim that LEDs last forever. “In truth,” he said, “they can last a long time, but their light does slowly fade over time. Their lifetime depends on the quality of the fixture design, how hard the LED is driven, and the ambient temperature in which it operates.”

The second myth that Koerner addressed is that LEDs generate no heat. He said they do generate heat on the back side of the LED. With today’s sources, the amount generated is only about half as much as incandescent sources, but twice as much as fluorescent sources.

Third, Koerner clarified the myth that LED efficacy is rated like other light sources. “LED efficacy is rated by chip manufacturers in a laboratory under ideal, impractical conditions.” Chip manufacturers test their products with millisecond “blink” tests at low temperatures with extremely high power. This approach produces an extremely high lumen/watt number, but once the LEDs are on for any length of time, they generate heat, which immediately lowers their output and efficacy.

Following the presentation, the Residential Lighting Committee met to discuss the presentation and identify additional information needs about SSL. They agreed that more information about how the technology works and how current products are performing would be helpful. “We’re working to bring members up to speed on this new technology so that they can evaluate when the time is right to begin programs for SSL products,” said CEE Senior Program Manger Rebecca Foster. “A recent cooperative agreement with the Department of Energy is providing CEE with additional resources to undertake this work, and assist members in accurately informing their customers about the advantages and constraints of this emerging light source.”

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