CARLSBAD — The next time city crews are dispatched to replace a burned out streetlight, they will likely replace it with a new energy efficient model under a contract approved Tuesday by the Carlsbad City Council. City staff has estimated that once all of the city’s existing high-pressure sodium lights are replaced with energy efficient induction lights, the project will save nearly $400,000 a year in energy and maintenance costs while reducing the city’s greenhouse gas emissions.
“This project benefits the environment and taxpayers,” said Thomas Moore, Transportation Department superintendent for the city of Carlsbad, who is overseeing the project. “It’s a great example of how the city is using technology to improve our operations.”
In addition to using the new lights to replace burned out lights, the city will begin a systematic replacement of all city streetlights that will take 14 to 16 months.
US Lighting Tech was selected to provide up to 7,000 of the new lights, which meet the “Buy America” provisions of the American Recovery and Reinvestment Act and have been approved by the Department of Energy.
The total estimated costs for the streetlight replacement program are anticipated at about $2.5 million. In September, City Council accepted a $938,900 grant from the U.S. Department of Energy to help fund the project. Other funding comes from San Diego Gas & Electric incentives and a 1 percent interest loan from the California Energy Commission. The loan will be repaid through savings in annual maintenance and electricity costs.
The switch to the new lights will reduce the city’s energy consumption for street lighting from 5.1 million kilowatts a year, to just more than 2 million kilowatts. Once the new lights are in place, the city will see a reduction of 1,240 tons per year of greenhouse gas emissions, the equivalent of taking 170 cars off the road for a year, or planting 124,046 trees.
Induction lamps have an expected life span of 100,000 hours or 24 years, versus a 25,000-hour lifespan or six years, for the current high-pressure sodium lamps. The last major change to the city’s streetlights occurred 30 years ago, when the city changed from mercury vapor lights to the present high-pressure sodium lights.
Along with a reduction in greenhouse gas emissions, the new induction lights are made with less mercury than the current lights. Less mercury in the lights will save money on hazardous waste disposal and reduce impacts on the environment. The new induction lights contain one-tenth of the mercury as the current high-pressure sodium lights, and the mercury is in a solid form, rather than liquid or gas, which makes it easier to recover and recycle than the material used in the current lamps.
The vast majority of the new lights will use cut-off luminare fixtures that direct light downward. The new lights also have half the wattage of existing lights and produce less reflective glare.
The new lamps also offer a public safety benefit. Their illumination appears white rather than the yellow light of the high-pressure sodium lamps. Witnesses and crime victims are expected to be able to more accurately describe colors, facial features and other visual details to law enforcement.
The city has installed several induction lights in the downtown village area to test the lights effectiveness. During its research, city staff also tested LED lights, but determined induction lights have a more established track record, a longer warranty and are less expensive.