Blue Light Issue Feb 2010
8
“Blue” Light
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The IDA has suggested that "blue light" might cause some problems for outdoor lighting. This anlysis shows LEDs have less blue light than most traditional sources and suggests the priorities that we should work on together to help reduce the night time sky glow issues.
Transcript of Blue Light Issue Feb 2010
“Blue” Light
“Blue” Light Controversy
“…bluish light produces high levels of light pollution with significant environmental impact. Short wavelength light also increases sky glow disproportionately. In addition, blue light has a greater tendency to affect living organisms through disruption of their biological processes that rely upon natural cycles of daylight and darkness, such as the circadian rhythm. …Developers of light sources should be required to refine their products to limit blue light at wavelengths shorter than 500 nm.”
- IDA 10/7/2009
“…IDA’s recommendations of curtailing emissions of light wavelengths shorter than 500 nanometers over the complete life of the lamp and minimizing the use of light sources with a CCT above 3000 Kelvin are unsubstantiated, and are contrary to the Department of Energy’s mission to improve energy efficiency and environmental quality. High CCT lighting for outdoor applications should be neither mandated nor prohibited at a national level; qualified designers should be free to determine the relative importance of color and efficacy for any given project.”
- U.S. Department of Energy
Copyright © 2010, Cree, Inc. pg. 2
Dream Come True For Dark Skies…?
Courtesy of BetaLED
Copyright © 2010, Cree, Inc. pg. 3
Paved Surfaces Reflect 50% Less “Blue”*
* A Sustainable Approach to Outdoor Lighting Utilizing Concrete Pavement, Portland Concrete Association, 2009
Copyright © 2010, Cree, Inc. pg. 4
Metal Halide 4000K
“Blue Light” Spectral Comparison
Copyright © 2010, Cree, Inc. pg. 5
Cool White LED 6000K
Lamp Type % Energy <500nm
Metal Halide 34%
Cool White LED 31%
Mercury Vapor 27%
T8 Fluorescent 22%
Commercial White LED
20%
Commercial White LED 4000K
“Blue Light” Spectral Comparison
Copyright © 2010, Cree, Inc. pg. 6
Cool White LED 6000KCommercial White LED 4000KT8 Fluorescent 4000K
Lamp Type % Energy <500nm
Metal Halide 34%
Cool White LED 31%
Mercury Vapor 27%
T8 Fluorescent 22%
Commercial White LED
20%
“Blue Light” Spectral Comparison
Copyright © 2010, Cree, Inc. pg. 7
Cool White LED 6000KCommercial White LED 4000KMercury Vapor 4000K
Lamp Type % Energy <500nm
Metal Halide 34%
Cool White LED 31%
Mercury Vapor 27%
T8 Fluorescent 22%
Commercial White LED
20%
Working Together On The Top Priorities
1. Eliminate up-light with full cut-off traditional or LED luminaires (LED technology makes designing zero- up-light fixtures straight-forward)
2. Reduce overall outdoor lighting levels by standardizing the unified photometry work of LRChttp://www.lrc.rpi.edu/programs/solidstate/assist/pdf/AR-VisualEfficacy-Jan2009.pdf
3. Accelerate serious academic investigation of the “blue light” issue including actual levels of blue light reflected, environmental impact, and impact on Rayleigh scattering
Copyright © 2010, Cree, Inc. pg. 8
