CHICAGO (WBBM Newsradio) — The city has reached a new milestone in its plan to replace all its street lights with more energy-efficient LED bulbs.

Mayor Rahm Emanuel toured Lyons View Manufacturing on Friday, where workers were assembling the LED lights that will replace existing high pressure sodium lamps. He said, to date, 18,000 have been replaced.

“It’s good for the environment, good for our energy-use, saves dollars, and makes our residential streets all that much safer,” he said.

Lyons View president Joshua Davis said some of the workers on the assembly line are ex-offenders.

“Recently, when one of my colleagues was asked what he wants them to know about the new lights, he said ‘that they were made by a black man right here in Chicago,’” Davis said.

The new lights not only will save the city millions on energy costs, but will change the way the streets look at night.

“This is a white light, and not the orange-yellow glow that the city is seeing with the high pressure sodium,” Chicago Infrastructure Trust executive director Leslie Darling said.

During testing of the new lights last year, students studying light pollution found the LED lights are more painful on the eyes than the old ones. In response, the city agreed to put light shields on the new lamps to reduce glare.

The city has said the new lamps will allow for real-time monitoring of outages, will last much longer than the older bulbs, and allow the city to dim or brighten fixtures remotely.

“Because it’s all part of a smart grid, you don’t have to rely on residents to call 311 when a light is out. The system will know it, and dispatch somebody to fix the light or change the light,” Emanuel said.

Darling said the project is one of the largest LED street light conversion programs in the country.

Officials said all 270,00 city street lights should be converted to LED lamps in four years.