Are LEDs good for dark skies?
Unfortunately, no… they could be, but as they are presently being used, they are almost always not. Not even close.
Tucson has demonstrated a more aggressive approach, but still left significant benefits on the table by switching to whiteinstead of an amber , and Tucson had more to lose due to their now abandoned amber lighting standards.
So the conclusions are clear – switching to white LEDs from the current yellow light technologies using sodium lamps saves only a little energy, much less than is being touted, unless lighting is dramatically reduced. Butin the vast majority of retrofits is dramatically increasing.
- First and foremost, use yellow LEDs (not low- white LEDs)! with a spectrum similar to (0.4x the impact of ), or with a spectrum similar to (0.7-1.6x the impact of ) should be used, or at worst filtered warm-white LEDs (1.5x the impact of ). These are not the most efficient LEDs at present, but can be a good tradeoff to balance energy and dark sky impacts.
- Take advantage of dimming technologies to dim or turn off lights when activity or traffic levels justify it.
…And for any light type:
- Only light roadways when a full assessment of costs (both fiscal and environmental) and benefits, including fiscal, environmental, and safety, shows overall benefits.
- Always use fixtures.
- Use the lowest illumination level possible.
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