Consider it a green light for energy savings.

A handful of city officials on Thursday celebrated briefly at Ninth and Massachusetts as crews completed a multi-year project to replace all incandescent traffic signal bulbs with energy-efficient LED lights.

City Engineer Shoeb Uddin estimates the swapping of more than 3,000 traffic signal bulbs with the new LED bulbs will save the city more than $100,000 a year on electricity costs.

“We think it is a big deal worthy of some celebration,” said Uddin, who was on hand to watch the last bulb be put in place at Ninth and Massachusetts.

The city began replacing the bulbs in the mid 1990s, and it believes it was the first city in the state to begin doing so. The city, however, took several years to complete the project because it bought bulbs only as funding became available.

The new LED bulbs cost about $85 compared to about $5 for an incandescent bulb. But the energy savings on the bulbs can approach 90 percent, and Uddin estimates the energy savings pay for the bulb after about 2.5 years.

The bulbs are guaranteed to last for at least five years, and the company pays to replace the bulb if they fail before then. A traditional incandescent traffic signal bulb lasts about a year, said Tommy Sutton, a senior traffic technician who replaces many of the city’s traffic signal bulbs.

Sutton said the bulbs also will save the city significant amounts of money in overtime because the city currently has a policy to replace a red bulb as soon as the city becomes aware that it has burnt out. That means in the middle of the night or on holidays. Fewer burnouts should result in less overtime charges for the city.

But Sutton said there was something else that convinced him the new bulbs were going to be a money saver. Westar Energy had to install new digital meters at each of the traffic signals.

“With the old bulbs, you could watch that meter spin just like at your house,” Sutton said. “With the new bulbs, Westar thought their meters were broken because they didn’t hardly move.”