Santa Rosa has been working to slash its PG&E bill ever since the recession knocked its budget's lights out four years ago.
It started by darkening thousands of its 16,000 streetlights in largely quiet residential areas.
Then it put others on timers, cutting in half the number of hours they were lit each evening on the theory that a little light is better than none.
Now, the city has embarked on the third phase of its energy-saving effort by replacing hundreds of existing streetlamps at intersections with new, super-efficient bulbs that cost less to operate and will last more than three times longer.
Signalized intersections are the focus of the latest effort because turning existing streetlights off isn't an option for safety reasons. It's also where the upgrades make the most financial sense.
"The energy bang for the buck is the highest at those locations," said Steve Kroeck, deputy director of field services for the transit and public works department.
Streetlights aren't metered like homes. The city pays on a per-pole basis depending on the wattage of the bulb. A 250-watt high-pressure sodium bulb found at many intersections, for example, costs the city $146 a year to operate.
But the new, 150-watt induction bulbs replacing them produce plenty of light but cost $74 annually, a nearly 50 percent savings, said John Miklaucic, a supervising electrical technician.
Total savings from the program isn't clear because the 775 new bulbs are still being installed, Miklaucic said. But whatever the figure, it's going to be worth it to the city because $400,000 in federal stimulus money paid for the new bulbs and the labor to install them.
"We wouldn't have done this on our own dime," Miklaucic said. "It just wouldn't have happened."