It's not terribly expensive to leave a porch light on at night.
But imagine having 24,000 lights on sundown to sunrise — each using enough juice to illuminate a city street.
City Hall's bill for that, and related maintenance, runs more than $3 million a year.
"Fortunately, we do have a lot of lighting for the citizens," said Brian Coon, the city's assistant traffic engineer. "Unfortunately, it costs a lot of money to keep them lit."
And the cost is rising as the city adds more lighting in key places, such as Intrust Bank Arena, and expands subdivision by subdivision at its fringes.
That type of growth pushed the city beyond its street lighting budget by about $95,000 this year, leading the Wichita City Council to approve a budget change earlier this week.
Some of the reasons:
In 2010, the city put new lights along a mile of Maize Road, a mile of East 13th Street 2 1/2 miles of East 21st Street and a mile of Greenwich Road.
It also installed decorative lights at the newly expanded 21st and Broadway intersection, a stretch of South Broadway and the parking lots surrounding Intrust Bank Arena.
That's on top of the 250 or so lights the city says it typically adds a year.
"Everyone wants lights, but no one wants to pay for them," Coon said.
Most street lights are owned and maintained by Westar Energy. The city pays a set rate per light — whether the light is on or not.
The cost varies depending on the type of bulb.
The high-pressure sodium lights that give off a dull, orange light cost $10.81 a month. Those lights are common on stretches of road without major intersections.
The metal halide lamps that have bright white light run $27.66. Those are common at intersections.
Coon said the city considers a variety of factors when picking which light to use.
People tend to prefer the white light, and the city tends to use those in places where it has invested a lot, such as the Nomar International Market being developed at 21st Street and Broadway.
The police department can pick spots for up to 10 lights a year, and the city provides more when police request it.
Sometimes, the city will put the brighter halide lights in crime-plagued areas because the brighter light tends to ward off criminals and helps witnesses more clearly identify colors.
Other times, the city has painted part of the lamp black to prevent light from shining into people's homes.
The city also has basic standards for its lighting program. Most blocks that are 1,000 feet long or longer have a mid-block light. And the city tries to light all intersections.
Meanwhile, many people have privately added street lights via Westar Energy.
Increasingly, the city is exploring LED lights, which have a lot longer life span and produce brighter light.
The city used LED lights at Kellogg and Armour and Kellogg and Rock Road in east Wichita.
The initial cost is much higher, but savings can be realized over the lights' longer life span.
Coon said LED lights also reduce the number of times workers have to replace bulbs, a job that is often done with a lift truck parked on a busy street.
Fewer replacements means fewer people are risking their lives replacing bulbs, Coon said.
"It becomes a really tough equation," he said.