Pitt researchers think the city can save millions by switching its light bulbs, and city… Pitt researchers think the city can save millions by switching its light bulbs, and city officials seem to like the idea.

Engineering professors Melissa Bilec and Joe Marriott found that the city could save up to $1 million in energy costs and $700,000 in maintenance costs per year if it replaces the conventional high-pressure sodium lamps it uses now with energy-efficient LED lamps.

Because of the study, Mayor Luke Ravenstahl favors switching to LED lamps, said Lindsay Baxter, his sustainability coordinator. She said the mayor’s office is awaiting the results of further Pitt studies currently underway, but that the conversion could begin this summer.

City Councilman Bill Peduto, who represents parts of Oakland and Shadyside, released a report saying that each LED lamp will cost $500. According to the report, factoring in the cost of installation would run the total cost to about $24 million to replace the city’s 40,000 streetlights.

Michael Cherock, founder of Powerhouse Design Architects and Engineers, is working to create a lighting code that would set lighting standards for the city.

“We will have to buy a progressive technology that’s still in its infancy, but there are so many potential rewards that make it enticing,” Cherock said.

To pay for the lights, the city would use state funding provided by the Guaranteed Energy Savings Agreement, which helps cities and buildings become more environmentally friendly. What the state funding doesn’t cover, the city would pay off over a period of 15 years or less using its savings.

Bilec and Marriott completed their study with help from Pitt’s Mascaro Center for Sustainable Innovation. They were part of a task force that included Ravenstahl, Peduto and lighting consultants.

Bilec, Marriott and three Pitt undergraduates installed different bulbs in 150 streetlights in the South Side. They measured energy usage, the bulbs’ longevity, quality and environmental friendliness. They also gathered public opinion.

They found that while the LED lights are more expensive to produce, they only use 93 watts of power, compared to the 230 watts of power the current high-pressure sodium lamps use. The LED lamps also last 10 to 15 years, while the High Pressure Sodium lamps last two to four years.

The study also found that switching to LED lights would reduce the city’s carbon dioxide emissions by 6,818 metric tons per year, or about one-third.

There are a few areas in which other lights trump the LED bulbs.

LED lights might disturb some local animals.

“There’s an issue with the temperature. It can disrupt circadian rhythms of certain species,” Bilec said.

The Pittsburgh Post-Gazette reported that the LED lights cast a bluish glow that prevents people from seeing colors accurately. Peduto’s report, however, says LEDs “produce a white light that stimulates the rods and cones of our eyes.”

LED lamps have already been installed on Walnut Street in Shadyside, part of Peduto’s district. Peduto said, “The superior quality of the lighting is obvious.”