A new outdoor lighting technology called “lunar-resonant streetlights” is coming that will enable streetlights to respond to ambient moonlight which dims and brightens each month in line with the moon’s phases?
The beauty of this technology is that on clear nights when the moon is full, streetlights could turn off completely. This approach could save as much as 80–90 percent of the energy used for streetlighting.
Equally, the technology could be used for domestic outdoor lighting applications to bring back the experience of natural moonlight and a star lit sky to residential areas.
The concept is a small and simple intervention but it could impact light pollution and energy use on a global scale. It can be used to retrofit existing streetlights with dimmable LED bulbs and a highly sensitive photo-sensor cell that detects and respond to moonlight.
Now prepare to be amazed - research indicates that streetlights consume 38 percent of the electricity used for lighting in the United States. This generates close to 300 million tons of carbon emissions a year!
Streetlights are also the top source of light pollution that prevents most Americans from seeing stars at night. Switching to dimmable LEDs and using more responsive sensor cells could save the bulk of that wasted energy.
Incredibly however, streetlights became a convenient way in the 1930s to off-load excess energy from the grid at night, when power demands dropped significantly. It was this intentionally inefficient system determined the norm for nighttime outdoor lighting levels.
This wasteful standard has never been revised, even though off-loading electricity ended in the 1970s. What we now assume is a safety measure is in fact a forgotten leftover of an obsolete energy practice.
Current lighting standards are based on comfort levels and perceptions regarding nighttime safety, but since the off-loading started in the 1930s, people have become accustomed to the feel of brightly lit streets and parking lots. But ironically, studies have shown no link between outdoor lighting intensity and crime or accident rates. In fact it’s actually more dangerous dealing with the drastic variation in light levels within an urban area because your eye does not have time to adjust and so your vision is impaired.
So watch out for this technology appearing for domestic outdoor lighting application. You can follow its progress via Civil Twilight.
