This link has been bookmarked by 2 people . It was first bookmarked on 06 May 2008, by Todd Suomela.
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06 May 08
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new approach to outdoor lighting, the group asks: What if streetlights could respond to ambient moonlight, dimming and brightening each month as the moon cycles through its phases? On clear nights when the moon is full, streetlights might even turn off completely. The scheme, which they call “lunar-resonant streetlights,” could save as much as 80–90 percent of the energy used in streetlighting while bringing back the experience of moonlight and stargazing to urban areas.
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Civil Twilight’s research indicates that streetlights account for 38 percent of the electricity used for lighting in the United States—that’s close to 300 million tons of carbon emissions a year. They’re also the top source of light pollution, preventing two-thirds of Americans from seeing stars at night. The collective estimates that switching to dimmable LEDs and more responsive sensor cells could save the majority of that energy and bring the night sky back into the lives of urban dwellers.
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Perhaps the most fascinating fact that the collective’s research revealed, however, is a little-known detail about the history of electricity: in the 1930s, with the spread of electrification and the consolidation of utilities, streetlights became a convenient way to off-load excess energy from the grid at night, when power demands dropped significantly. This intentionally inefficient system determined the norm for nighttime outdoor lighting levels, a standard that has not been revised since, even though the need for off-loading ended in the 1970s. What we now assume is a safety measure is in fact the forgotten remnant of an obsolete energy practice.
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So what are the current standards based on? Comfort levels and perceptions regarding nighttime safety. Since the off-loading days of the 1930s, we’ve 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. What’s more dangerous, Willis says, is the drastic variation in light levels within an urban area. As you drive, for example, from a well-lit major thoroughfare to a darkened residential street, your eye does not have time to adjust, and your vision is impaired.
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25 May 07
Fogday StudiosThis year’s Next Generation winner looks to remake our urban spaces and skies by harnessing the illuminating beauty of the moon.
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