LED signals could save city $120,000 a year

Fort Smith officials say a conversion of all 149 signalized intersections in Fort Smith from incandescent bulbs to LED lights will save at least $120,000 a year in electric costs and reduced labor and maintenance costs.

The city’s Streets and Traffic Control Department is expected to complete in early August the conversion to the LED technology that is not only easier for motorists to see, but uses between 80 and 90% less electricity.

Steve Kelton, Fort Smith’s traffic control superintendent, said during the past five years the city converted 85 signalized intersections to LED. The remaining 64 were funded with $158,000 in stimulus dollars from the U.S. Department of Energy.

The conversion of 85 signals — paid for with money from the city’s street program — reduced electric costs from $15,000 to about $8,500 a month. When all are converted, Kelton estimates the monthly electric bill for signalized lights will be about $5,000.

Kelton said the annual savings — estimated at $120,000 — does not include the reduced time the five-person department spends replacing bulbs and other maintenance related to using incandescent bulbs — such as incandescent bulbs burn hotter and require more frequent replacement of cover shields.

In the past year, Kelton’s crew changed 670 incandescent lamps on the 64 intersections now being converted to LED. In the same period, the crew had to replace 38 LED fixtures at the other 85 intersections. Most LED fixtures come with a 5- to 7-year warranty, Kelton said.

“Preventive maintenance in our business is a very big deal. … And with 149 intersections and basically three guys in the field, we struggle to get to all of them and do the thorough maintenance procedures we need to do every year. And this will really help us do more of that,” Kelton explained.

In addition to the savings and reduced maintenance time and costs, Kelton said safety is also a benefit.

“To us, it is just as important that our guys aren’t in a lane of traffic up in a bucket on a busy Rogers Avenue. First, that doesn’t make us a lot of friends to be stopping traffic. … But our guys now won’t be in harms way nearly as often,” Kelton said.

PAYBACK
The cost per signal to complete the 64 signals using the stimulus funds is $2,468, but Kelton said the cost to complete some intersection signals when the program first began five years was as high as $7,000 per signal. Intersections, obviously, are different and the number of lights needed vary depending on the number of lanes, crosswalks and other features.

However, assuming an average cost of $5,000 for the 85 signals completed without the federal funding, the city will have spent $425,000. (Kelton said it is difficult to estimate the total cost of converting the 149 signals and would not concur with the previous assumption. He also said the average cost does not include the higher maintenance costs that would be associated with the signals if LED technology were not installed.) If the city saves around $120,000 on lower utility and maintenance costs, the LED signals will pay for themselves in 3.54 years. Considering that the program began five years, ago, the initial investment may already be recovered with some intersections.

SAVINGS STUDY
Regardless of what the actual costs and eventual payoff (the city has agreed to crunch some numbers and provide an estimate), there is little question that LED signals save money and time.

The Arkansas Department of Economic Development in 2003 studied selected LED intersections in Little Rock and concluded: “Due to the many advantages in terms of operation and energy consumption, the benefits of LED signals outweigh the initial investment.”

Using realized utility savings from 10 LED intersections in Little Rock, the AEDC report determined that when all 263 intersections are converted to LED, the city would save $111,000 a year.

The AEDC study also cited benefits of LED signals that were not quantified in terms of cost savings.
• LED Signals are brighter than conventional signals.
• LED signals do not burn the lens coverings like the conventional incandescent bulbs.
• Because LED signals require very low power to operate, it is feasible to run the signals with battery back-up during power failures.
• Because LED signals draw very low power, the intersection wiring will not deteriorate as rapidly resulting in less maintenance.

BROAD ACCEPTANCE
In 2001, officials in Portland, Ore., worked out a deal with a local utility to finance the $2.2 million needed to replace more than 13,300 signal lights. The deal resulted in the city saving $335,000 a year in utility costs and $45,000 a year in maintenance costs.

In 2010, Philadelphia officials began replacing 55,000 incandescent lights in the city. According to Philly.com, half of the $6 million project was paid by a U.S. Department of Energy grant, and half from Peco Energy. The lights are expected to conserve enough energy to power 700 homes and save the city $1 million a year in electric costs.

According to the L.A. Daily News, Los Angeles Mayor Antonio Villaraigosa recently announced the completion of a five-year LED signal conversion program expected to save the city about $4 million annually. The city also is in the midst of converting 140,000 of its about 210,000 street lights to LEDs — a move that will save about $10 million a year in electric costs.

There are downsides to LED signals. The visibility of LED signals are directional which may cause visual problems for signals attached to span wires that sway during high winds. Also, during heavy snowstorms, LED signals do not generate enough heat to melt snow.