PHILADELPHIA (WPVI) -- You might notice that some street lights in the city have a slightly different glow.
Roughly 8,500 street lights in Philadelphia have been converted to LED's in recent years, but the city is about to pick up the pace. LED's generate more light with less power.
"Our energy bill will go down. Our carbon footprint will go down. The goal of this project is to pay itself back in a 20-year-period," explained Deputy Commissioner Richard Montanez of the Streets Department.
Philadelphia is now looking for vendors to replace the remaining 100,000+ high pressure sodium lights over the next several years.
Montanez said the city spends roughly $15 million a year on streetlights. With LEDs, the city could save $5-$6 million annually.
"The technology keeps advancing as we do this project , and I guess the benefit we've had is that we waited so long," added Montanez.
Christine Knapp works in the city's Office of Sustainability.
"We think that the conversion project could cost between $50-80 million, but we think the savings would actually cover that," Knapp said.
Knapp explained Peco's restructured tariff provides more motivation for the switch.
"Now there is a lower flat rate and a higher electricity charge, which then gives us the incentive to cut that electricity use and save more money," Knapp elaborated.
City officials told 6abc it is becoming harder and harder to find affordable replacement parts for the old fixtures because their suppliers are switching to LEDs.
The city is also looking for a new system to manage streetlights, which could customize lighting to neighborhoods.
High crime areas could be flooded with light. Residential areas could be dimmed, if preferred.
They've been able to test this out.
Montanez described how in a nighttime Hillary Clinton rally in 2016, law enforcement asked the city turn the lights up to full force during the rally. The lights were later dimmed.
"The technology has changed a lot. It's made it more attractive, it's made it more cost effective, it's given us more of those customization options that we know are attractive," Knapp concluded.
There have been concerns raised about the safety of LED lights.The city is consulting medical professionals about those concerns.
City officials will also seek feedback from the public down the line, as they tailor their plans to different neighborhoods.