let there be less light |
The city of Santa Fe’s recent streetlight remodeling project left some stargazers and night-time drivers with more knowledge of Kelvin and kilowatt-hours than a layman cares to know. Considerations were made for safety, energy efficiency and the preservation of a dark night sky.
Last October, city authorities began installing LED lights in streetlights. The $2.9 million project was part of the city’s effort to become carbon neutral by 2040, with the added benefit of saving $556,000 annually in utility bills and 2 million kilowatt-hours of energy per year (an electric dishwasher uses about 2 kilowatt hours per charge). ). The city owns about 3,000 of the 5,000 streetlights in the city; The Public Service Company of New Mexico owns the remainder, which has yet to be remodeled.
So have Mayor Alan Webber and other city officials announced the project as reducing light pollution – but not everyone agreed.
The Santa Fe Conservation Trust, a non-profit organization working to protect culturally and ecologically significant landscapes, was concerned that the new lights would be too far in the blue spectrum, “leading to more light pollution and having more impact on all living things says executive director Sarah Noss. The group praised the city for its efforts to save energy but advocated a more amber hue for the new LEDs.
The new streetlights are “the warmest, darkest design you can make,” within certain parameters, Regina Wheeler, the city’s director of public works, tells SFR, citing a 10-year warranty from a tier-one manufacturer and lamps that meet national safety standards.
Conservation Trust members believe the switch has boosted the sky’s glow, but they don’t know for sure because there’s no baseline to compare the new lights to. Now they want to change that by installing light monitoring devices on Santa Fe County buildings, including fire stations that collect light pollution data every five minutes throughout the night.
Retired astrophysicist Sam Finn introduced the group to the monitoring equipment, and the trust will be part of a long-term light pollution study it is tackling Flagstaff Dark Skies Coalition.
The work will help “keep an eye on light pollution,” says Noss. “Having that kind of information in our quiver would give us a better understanding of whether we needed to improve our night sky protection laws.”
Finn says the only data available now comes from weather satellites, “but this data is crude and you have to make a number of assumptions in order to use it to make statements about changes in light intensity,” he adds.
The Trust is working with Santa Fe County Commissioner Hank Hughes to complete the placement of the equipment. Hughes supports the project.
“I’ve lived here for over 30 years and we’ve already seen the sky brighten with the lights in Santa Fe,” Hughes tells SFR. “There’s already some deterioration so I think it’s important not to let it get any worse and hopefully maybe even make it a little bit better.”
According to Noss, the group plans to use three monitoring stations — one north of the city, one south and one southeast — to collect 10 years’ worth of data to track light pollution in northern Santa Fe County, including within city limits.
“We had to place them far enough out of town so that we could really assess the dome light,” says Noss, “and we also had to place them in areas where the ambient light — streetlights and traffic lights and things like that — wouldn’t really affect the data.” .”
The Trust downloads the data every few weeks and analyzes it on site and sends it to the group in Flagstaff for analysis.
“It’s a pretty big deal, but we think we can do it and we’re committed to it because we really want to protect the night sky as best we can,” says Noss.
Charitable donations to the Conservation Trust will fund the project. Noss estimates the startup cost at $7,000, with annual costs of about $1,000 for data downloads and device maintenance.
The dark celestial shield in the books “doesn’t really have teeth,” says Noss. “We hope that if we can show that things are changing fairly quickly in terms of our ability to see the night sky, it would help us reinforce the statutes that already exist.”
Santa Fe’s light pollution ordinances have not been updated since 2011, although the city passed specifications for intelligent street lighting design in 2021, which will be included in the code when it is updated.
Wheeler would also like to see stricter regulations, although she believes the city’s streetlight upgrade has improved light pollution.
“Through this whole streetlighting process, we realized that we really wanted to be a dark sky community,” she says. “One of the phases of that would be to really talk to the private sector about how they can do better, and then make our regulations stricter.”
The city is rewriting the land use code, which Wheeler describes as a “golden opportunity” for this type of work. But with the engineering division director, engineering supervisors and other staff vacancies, she says it will be a slow process.
The city’s next step is to convert PNM’s own lights.
“Because some of the specs we came up with were so advanced in terms of our lighting design, [PNM] actually had to go get it [Public Regulation Commission] permission to install this type of equipment,” says Wheeler.
She expects to receive an offer from PNM in the next few months.
“I’m guessing we’ll probably get into business with a new rebuild in January,” says Wheeler.
The stakes are high for the Conservation Trust.
“What’s important to me about preserving the night sky is that it’s a natural resource that has always been there,” says Noss. “If we can preserve the night sky, we are looking at the same stars that our ancestors looked at, worshiped and built their lives around.”
In addition, lighting affects melatonin levels in humans, she says: the brighter the night sky, the poorer the quality of sleep. And that’s just the human impact — she says it affects animal mating patterns, how flowering plants open at night, feeding insects and more.
The good news, she says, is that dark skies are “fully recoverable” by reducing certain types of lighting (like light reflected off sidewalks by streetlights).
“It’s not the hardest thing in the world if everyone knows why,” says Noss.