COLUMBIA — Columbia’s Environment and Energy Commission is looking at technologies it might recommend to replace about 8,000 of the city’s street lights to make them more energy efficient.
The street lights currently work by running an electric current through mercury vapor as opposed to using the tungsten filament of an incandescent light bulb or the gas within a neon sign.
These mercury-vapor lights use the same amount of power throughout their lifetime, but their light output decreases over time — which means they become more inefficient as they age.
Manufacturers are beginning to phase out production of the lights following a federal law passed in 2005, commission member Ted Dyer said.
The city isn’t sure how many mercury-vapor lights it has installed but estimates it has about 8,000, Dyer said. A staff member from Columbia Water and Light is in the process of manually counting them every night; Dyer said that count should be done by mid-July.
Dyer emphasized the need for the city to switch to more energy-efficient lighting.
“Those fixtures are a money pit,” Dyer said of the mercury-vapor lights. “We are throwing a lot of our hard-earned energy right straight down a rathole by feeding a light that’s only putting out half of what it should.”
The city is researching two more efficient alternatives based on other cities’ experiences: lights based on sodium vapor and light-emitting diodes. The sodium lights have been in use for several years, but LEDs, which are commonly used in smaller appliances such as flashlights and electronic device indicator lights, are being marketed as more efficient and easy to service.
“The first big push will be low pressure sodium,” Dyer said, noting that the replacement project “will probably be well under way before LEDs are fully researched.”
Dyer has not said which cities he has contacted but said many communities are facing the same problem.
The city of Newton, Mass., replaced all 8,440 of its mercury-vapor lights with high-pressure sodium lights last year.
According to David Tannozzini of the Newton Citizens Commission on Energy, the $3 million project will save the city $760,000 in energy costs every year, which means the replacement will pay for itself in only four years.
In Canada, the city of Welland, Ontario, began a pilot test of LED street lights in October. The test replaced 47 of the city’s high-pressure sodium lights with LED fixtures, resulting in a 52 percent decrease in energy consumption, said David Ferguson, Welland’s manager of traffic and parking operation.
Welland plans to replace about 12 of its downtown street lights with LEDs as an additional test, Ferguson said.
Although 72 percent of Welland’s citizens support the project, Ferguson suggested that cities considering a similar switch should conduct their own studies before moving forward.
“Some people don’t like them, some people do, so it’s better to do a pilot project first,” Ferguson said.
Dyer said he has some concerns about materials and chemicals used in the manufacture of LEDs and a relative lack of information from other cities about the results of their own tests, but said he was encouraged by the City Council’s response to the issue at its work session on May 31.
“I was pleasantly surprised at the reception,” Dyer said. “We got into some areas that have evidently been sore spots for a long time, and the idea of moving forward and doing some bridge-building and settling these issues in a timely and effective way was a very pleasant surprise for me.”
After the commission’s May 27 meeting, Dyer said this issue isn’t one to be taken lightly.
“This is going to have a lot to do with what the city’s going to look like every night,” he said.