Evansville to install LED streetlights
Upgrading 250 mercury vapor and high-pressure sodium streetlights to LED bulbs is expected to save about 80,000 kilowatt hours of electricity, cutting the city’s electric bill by $8,000 a year, Mayor Sandy Decker said.
The switch brings other savings including:
-- An estimated 55 percent reduction in energy usage.
-- Carbon dioxide emissions reduction of 135,360 pounds per year.
-- Labor savings from not replacing bulbs every two to three years. The Energy Center of Wisconsin estimates LED lamps will last 25 years, though Decker said they’ve seen reports that they last as long as 30 to 50 years.
The project moves the city closer to its goal of getting 25 percent of electricity and 25 percent of transportation fuels from renewable resources by 2025.
The city started exploring the idea of LED streetlights a couple years ago and has been sampling bulbs for 18 months.
The test found that streetlights with a single 100-watt sodium bulb used 700 kilowatt hours in 18 months, while a streetlight with an array of 30 small LED bulbs used 340 kilowatt hours, said John Rasmussen of the water and light utility. Both give a similar amount of light, he said.
“A lot of communities around the state were looking at upgrading their street lights to LEDs because of the efficiency of them,” Decker said.
LED streetlights are expensive, she said, but a state Office of Energy Independence grant program funded by federal stimulus money helps communities upgrade to LED streetlights, she said.
Evansville received a grant of nearly $134,000. About $108,000 of it will be used for the new streetlights with the remainder going to energy efficiency upgrades in the public works garage, Decker said. The winning bid for 250 lights was $338 per unit.
The new lights will arrive in a couple weeks, and about 75 percent of the city’s 409 streetlights will be fitted with LEDs.
“It’s our intention to get these up by the end of the year,” Decker said. “We’d like to start seeing the savings.”
Crews will start by replacing 44 mercury vapor lights, which used 1,180 kilowatt hours during the 18-month test, Rasmussen said.
The remaining new bulbs will be installed by block starting in the center of the city, in heavily traveled areas and around schools, he said.
The project has area ties because the supplier is Crescent Lighting of Middleton, and the lights are from Beta Lighting in Sturtevant, a company of Ruud Lighting headquartered in Racine, Decker said.
SODIUM VERSUS LED
Color: High-pressure sodium lights cast an orange glow, while LED bulbs provide a whiter, more natural light.
Efficiency: In Evansville’s 18-month test, the sodium lights used more than twice as much electricity as the LED lights.
Cost: A sodium bulb costs $40 to $50, while an LED bulb—an array of 30 small bulbs—can be about $330.
Lifetime: Some sodium bulbs last six months, and some last eight to 10 years, said John Rasmussen of the water and light utility. The Energy Center of Wisconsin estimates the lifetime of LED lamps at 25 years, though other sources say the lamps last 30 to 50 years.
The bulb: Sodium bulbs can have a short life if someone shoots a BB gun at the light, Rasmussen said. An LED bulb is made up of 30 little bulbs, so if a couple go out, the rest of the bulbs will remain lit.