Phoenix plans to convert its entire traffic signal system to light-emitting diode (LED) lamps by the end of 2011, which will save the city $600,000 a year, according to Lisa Honebrink, a spokeswoman for the Phoenix Office of Environmental Programs.

In mid-October, the Phoenix Public Works and Street Transportation departments began working with Ameresco, an energy services company, to convert the city’s 860 intersections to LED lamps, which will use 90 percent less energy than the existing incandescent light bulbs.

The current conversion project, funded by the U.S. Department of Energy, began in mid-October, although the city began using LEDs in 2006 for all new traffic light installations.

The funding is a part of the Energy Efficiency and Conservation Block Grant program, funded by the American Recovery and Reinvestment Act of 2009, to encourage a nationwide effort to adapt greener technologies.

With an estimated annual energy reduction of more than 5 million kilowatt-hours, the project is expected to reduce emissions in Phoenix by 2,500 tons of carbon dioxide, 10 tons of sulfur dioxide and eight tons of nitrogen dioxide — equivalent to removing 475 cars from the road or powering 408 homes each year, according to Ameresco.

Along with less pollution, LED lights have a longer life span — about seven years compared to one year for an incandescent bulb — which is especially helpful since the city lost its re-lamping maintenance crew as part of a budget cut. The LED bulbs are about $50 more expensive to replace.

The cost to convert one intersection to LED units is about $10,500, Honebrink wrote in an e-mail.

The installation will be done in two phases, the first will be completed by April 2011, and the second phase will begin immediately after.

Besides the LED streetlights, Phoenix’s leaders are looking at energy efficiency from a broader perspective. In a separate initiative called Energize Phoenix, the city is partnering with Arizona State University and the Arizona Public Service to revamp the 10-mile stretch of the Phoenix Light Rail Corridor, where a large percentage of households live below the poverty line. The homes and commercial buildings will be retrofitted for energy efficiency, which is expected to create thousands of new jobs. This will be the first major project to be implemented as part of a larger sustainability project called Green Phoenix, designed in collaboration with Arizona State University’s Global Institute of Sustainability and funded by federal grant money from the U.S. Department of Energy and the stimulus.

Lauren Katims Nadeau  |  Contributing Writer