The City of Boulder will soon start saving about $3800 a year on the cost of energy to light its streets, representatives from NorthWestern Energy recently told city officials.
The savings will follow the replacement of about 90 high-pressure sodium street lamps with more-efficient LED versions.
The swap is expected to take place over three days later this month, NorthWestern Energy engineer Steve Schmitt told the City Council Sept. 16.
Howard Skjervem, the company’s Helena-based community relations manager, told the councilors and Mayor Rusty Giulio that NorthWestern Energy would cover the replacement costs.
“You would see the benefit of the energy savings going forward,”” he said.
Boulder’s 90 lamps are among 43,000 NorthWestern Energy operates statewide. Skjervem said that the company watched the development of LED lighting technology for about a decade before deciding to adopt it.
“When the first versions came out they were good but they weren’t where they should have been,” he explained, citing reliability and quality concerns.
“Energy efficiency is key to this [decision],” Skjervem said. “LED lights use less than half of what [energy] the high-pressure sodium lights use.” He estimated Boulder’s annual savings would be $3,842.
Replacing the company’s 43,000 lamps is a four-year project that started earlier this year in Billings, where Skjervem and Schmitt expected replacements would be completed within days of the Sept. 16 Boulder City Council meeting.
The replacement of lamps in Helena, Skjervem explained, has been delayed due to a lighting ordinance in Helena that conflicts with the lamp design chosen by NorthWestern Energy.
“We hired an engineering firm to see how we can resolve that,” he said.
The lamp design the company chose follows recommendations of the International Dark-Sky Association, which aims to reduce light pollution by regulating how such lighting is spread. Skjervem said the design they chose puts the lamps inside a hood that prevents light from shining upward into the sky.
Schmitt said they chose a 3000 degree Kelvin temperature light that will cause “a little bit of a change” in what people see, yet provide “a more accurate representation of the color” of whatever the light illuminates.
When a meeting attendee asked whether LED lights would provide as much a sense of safety in the extent of their illumination, Scmitt said that in areas where the change has been made “we’ve had a lot of people say ... this is an improvement over what it was.”
This phase of the replacement project in Boulder will only involve street lighting for which NorthWestern Energy charges the city. Replacing street lights for which the company charges private customers will occur in 2022 or 2023, Schmitt said.