Money-saving LED streetlights illuminate Tennessee town
Somerville, Tenn., a town that is situated about 50 miles east of Memphis, used to spend $100,000 a year to operate its streetlights. The town had about 450 street fixtures, so it was spending almost $225 per light. Bob Turner, who had recently been elected Somerville’s mayor, felt his community was spending far too much on street illumination.
“I talked to our city administrator about ways to cut costs,” Turner recalls. “He suggested that we eliminate half the lights in town. I didn’t think that was a very favorable solution.”
The other issue was the quality of the lighting, which was metal halide and mercury vapor. Turner hired a lighting engineer, and they headed out to the town’s streets with a meter to investigate at close range.
“First of all, there were four colors of light out there,” Turner says. “It was horrible.” The strength of the lighting was also an issue.
“We were standing right underneath one light, and it was measuring 0.1 foot candles on the meter,” Turner says. “We could barely read the meter with the light from the streetlight. None of it was hitting the street. “It was kind of eye opening.”
So Turner and staff began researching alternatives.
Town staff first looked into induction, but felt that the quality of the light degenerated too quickly. They were also hoping to eliminate the need for ballasts, which the induction lighting requires.
They then investigated LED, were impressed, and learned that between 2011 and 2014 the cost had come down considerably. That made for an easy choice.
Turner says the town didn’t have a particular LED manufacturer in mind; rather, it was a matter of who could best meet their specifications.
“We had a sealed bidding process,” he says. “We established the specifications and then looked for the bid that met the criteria.”
The choice was Cree XSP Series luminaires, which offer efficiency and longevity without sacrificing performance. Using NanoOptic Precision Delivery Grid optics, the XSP Series luminaires provide enhanced optical control delivering light where you need it, and not where you don’t.
In addition, the Cree luminaires allow the town to realize savings on maintenance costs.
“We went to the local electric co-op and worked out a deal to eliminate the maintenance contract on the lights,” Turner explains. “If you’ve got a light that’s going to last over 10 years, why do you need a maintenance contract?
“We made that point, and it was approved by the Tennessee Valley Authority. That eliminated the 14 percent a year we were being charged. We then bought the luminaires, gave them to the co-op to install, and we agreed to pay per light as they go out.”
The Cree luminaries have been installed since August 2014. Turner reports there have yet been only two failures. Both were quickly replaced without issue.
Turner, who now serves as Somerville’s city administrator, says that with the LED lights, the town has reduced average wattage per light from 400 to 100. The cost of electricity for the XSP2 streetlights has been reduced by 69 percent, saving, he says, “75 percent across the board on the whole project.”
“We originally budgeted more than $100,000 a year for our lights and now we budget $25,000,” Turner says. “That’s $75,000 in taxes saved in the general fund.” Through its savings, the town expects to earn its lighting investment back in well under two years.
For the future, Turner says: “I actually put $25,000 in our budget this year for additional street lighting.” That will buy the town 40 to 50 new lights – a somewhat more favorable solution than the original proposal to remove lights.
What has been removed, says Turner, is “a lot of moving parts. We no longer have ballasts. The lights come on and off immediately; it no longer takes 20 minutes for them to warm up.”
Somerville’s Street Light Energy Efficiency Program, as the overall project was called, earned the town a 2015 Excellence in Energy Efficiency award from the Tennessee Municipal League.