What are the purple streetlights around Chapel Hill?

Some Chapel Hill residents are seeing a strange sight when they drive around town at night — purple street lights.

Duke Energy is responsible for the upkeep of many of the area’s street lights. In recent years they have carried out the installation of new LED lights around the city and state.

Jeff Brooks, a Duke Energy spokesperson, said that the purple light coming from the street lights is a result of defective products.

"One batch of LED lighting, which was manufactured by a company called Acuity, has a defect in the coating for the lighting," Brooks said. "That coating in this defective fixture is wearing off, which causes the light to change gradually to a deep purple color."

Acuity Brands Lighting said in a statement that the effect produced by these lights occurred in a small percentage of light fixtures that they produced with components that have not been sold in their products for several years.

"It is due to a spectral shift caused by phosphor displacement seen years after initial installation," the statement said. "The light output is in no way harmful or unsafe. As always, we stand behind the quality of our products, and we have been proactively working with customers who have experienced the issue to address any concerns."

This issue is most prevalent in central and western North Carolina but has been recognized across the state, with Duke Energy asking residents to report any purple lights they see. 

Last year, Chapel Hill announced plans to convert over 2,000 public street lights into LED fixtures. Additionally, in 2017, the state-administered funds to add over 10,000 LED lights along highways. Duke Energy largely supports power in Chapel Hill and surrounding communities.

“This lighting is highly efficient and uses less power than traditional light fixtures," Brooks said. "It also typically has a cleaner light that helps to make colors stand out better and to illuminate sidewalks and other walking areas more clearly. In addition, it has direction which helps to cut down on ambient lighting in areas other than the spots we want it."

In Chapel Hill, the lights have become a part of the Town of Chapel Hill's Climate Action and Response Plan. LED lights help reduce the city's carbon footprint due to their energy efficiency. By emitting light in narrow bands of wavelengths, LEDs save more energy than incandescent or fluorescent lights, which are more commonly used.

“It's one of the many things we are doing to address climate change," Chapel Hill Mayor Pro Tem Michael Parker said. "The LED lights use significantly less electricity, allowing them to reduce greenhouse gas emissions."

Although the purple lights can be seen throughout the region, they are scattered and hard to spot. As a result, some residents have made a hobby out of searching for the lights.

“I am definitely on the lookout for these mysterious lights," photographer Tasso Hartzog, a first-year at UNC, said. "It's so unusual, a blue street light. I've done a shoot with one actually. I think the pictures are cool and I always document it whenever I see one around."

Brooks said that the lights are not a safety issue because they function with the same efficiency and emit the same amount of light. However, he added that Duke Energy wants to ensure they are consistent in all of their lighting.

He said Duke Energy encourages residents to report malfunctioning lights so that they can replace their bulbs as soon as possible.

If you spot a defective light you can report it to Duke Energy by using the “Street & Area Light Repair” form on their website or calling customer services at 1-800-777-9898.

@grantalxandr

@DTHCityState | city@dailytarheel.com 

CORRECTION: A previous version of this article misstated a word Jeff Brooks, a Duke Energy spokesperson, said when describing the malfunction in the LED lights that cause them to turn purple. He said it is a defect in the "coating." The Daily Tar Heel apologizes for this error.