Lighting the way

For decades, America’s nighttime cityscapes have been cast in a warm, yellow-orange glow. It’s familiar—some might say comforting—but it’s fading fast.

“It’s the only color we’ve known because streetlight technology has always been in that orange-ish color temperature,” said Skyler Lipski, Chico’s manager of public works. “Perhaps, given the option, we all would have chosen a more neutral color—something closer to the color of moonlight.”

There are nearly 7,000 streetlights in Chico, almost all being the traditional variety known as high-intensity discharge (HID). They have been the industry standard for more than 30 years, but are inefficient compared with what’s available today. The latest technology is light-emitting diode (LED) streetlights—about 10 percent of existing U.S. streetlights have been converted to LED—and the city of Chico is getting on board.

On May 3, the Chico City Council voted 6-1 to participate in Pacific Gas & Electric’s LED Street Light Turnkey Replacement Service, through which the utility giant is offering the city $145,950 to retrofit its streetlights, bringing the city’s cost down to about $1.2 million. The project is tentatively set to roll out on Monday (July 11), Lipski said, and will take about two months to complete.

“When all is said and done, every streetlight in Chico will be LED,” said Erik Gustafson, the city’s public works director-operations and maintenance.

LED streetlights clearly have some upside in terms of saving money and reducing use of fossil fuels. Nevertheless, one glaring through your bedroom window may be more than annoying.

On June 14, the American Medical Association issued a warning about poorly designed, high-intensity streetlights in residential neighborhoods and potentially negative impacts on human health.

“Blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night,” the statement reads. “It is estimated that white LED lamps have five times greater impact on circadian sleep rhythms than conventional street lamps.” The AMA goes on to cite big data studies that have linked brighter lighting in residential neighborhoods to reduced sleep times, dissatisfaction with quality of sleep, excessive sleepiness, impaired daytime functioning and obesity.

In some cities, there’s been public pushback. The city of Davis, for example, recently replaced about 650 LED streetlights due to widespread outcry.

During a phone conversation with the CN&R, Mitch Sears, sustainability program manager in Davis, said that the city installed about 200 LED streetlights as part of a pilot program in 2011. They seemed generally well-received; at least, no one was complaining.

The lights had a color temperature of 4,000 kelvins (K). (The higher the color temperature rating, the higher content of blue light there is, and the whiter the light appears.) Based on the pilot program, Davis chose the same color temperature when it extended the retrofit throughout the city in 2014, Sears said.

“As we started to put in these new lights, we got about halfway done with the residential portion of the city and we started to hear concerns,” he said. Public input was overwhelmingly negative; homeowners said the lights were glaring and intrusive. “Our City Council said, ‘Let’s take a timeout,’ and we went back to the drawing board.”

Ultimately, Davis decided to replace the lights with dimmer, 2,700 K fixtures, which happens to fall in line with the AMA’s new recommendation that residential streetlights not exceed 3,000 K. The citywide retrofit was completed about nine months ago, and complaints have since subsided.

“We feel like we found a decent balance point,” Sears said.

The new LED streetlights in Chico’s residential neighborhoods will be 3,000 K exactly. When installing the fixtures, the city will take additional measures to make sure the light doesn’t encroach on homes, Gustafson said.

“With LEDs, you can specify the exact light pattern and where you want it to hit,” he said. “The existing HIDs, they spill light everywhere and create a lot of light pollution. If there are intrusion scenarios, we’ll take those on a case-by-case basis. We can put external covers on the back or sides, depending on the location.”

The new lights won’t be the first LEDs in Chico. The city’s maintenance policy is that, if an HID light goes out, it’s replaced by an LED, and mostly commercial thoroughfares—including The Esplanade, East 20th Street, East Avenue and Park Avenue—were retrofitted with them a few years ago. To date, the city has received only two complaints regarding LED streetlights, Gustafson said.

He’s aware of the AMA warning, and pointed to a June 21 response from the U.S. Department of Energy that maintains that “there’s nothing inherently different about the blue light emitted by LEDs.”

“As the potential for undesirable effects from exposure to light at night emerges from evolving research, the implications apply to all light sources—including, but by no means limited to, LEDs.” The statement adds that people may also be adversely affected by watching TV or using a smartphone before bed.

From the perspective of energy and cost savings, Gustafson said, Chico’s LED retrofit is a slam-dunk. Each year, the city spends about $700,000 just keeping the lights on. LEDs use half as much energy as the current HID fixtures, which will save Chico an estimated $273,183 in annual electric utility costs, according to a city staff report. The project should pay for itself in less than five years. And, environmentally speaking, it will save about 1.6 million kilowatt hours of electricity and prevent the release of 831,500 pounds of carbon into the atmosphere.

“It’s hard to argue against an LED retrofit,” Gustafson said. “The environmental benefits are huge. The cost savings are huge. We probably spend $30,000 to $35,000 annually just sending staff members out to go change light bulbs and photo cells. An LEDs’ life cycle is much longer. We’re expecting not to touch these for 20 years.”