Pacific Gas & Electric recently installed large diesel generators for backup power at the Calistoga substation, as the utility replaces transmission lines in surrounding areas.
The 14 generators were initially fired up April 22, and caused such a loud noise disturbance that the city issued a Nixle alert and after several calls by Mayor Chris Canning, PG&E shut the generators down.
The company is now working on building baffles around the generators to mitigate the noise. The generators will begin running again May 19, and after that, they will run until May 30, on a 6 a.m. to 10 p.m. cycle, excluding weekends, said Deanna Contreras, spokesperson for the company.
“After May, we are planning to keep the generators in place through at least October to support the safety work in the area and keep customers supplied with electricity during times of peak usage. During this time, generator usage will be weather dependent and is likely to occur when we see temperatures climb to over 90 degrees in Napa or Lake Counties,” she said.
The generators will operate as needed to keep the area energized, which may include operations up to 24 hours a day.
Laura and Mike Swanton own a home and winery next to the substation, which is just off Lincoln Avenue and Silverado Trail. Mike Swanton said he measured the initial noise from the generators to be between 90–112 decibels, or the equivalent of NASCAR races.
PG&E has since improved communication with the Swantons, they said.
“They’ve been very, very responsive to us. They fine-tuned the generators so that the diesel smell is a lot more under control, and we just need to give them some time to figure out the baffling, so we’re trying to be patient on that,” Laura Swanton said.
Contreras said the company apologizes for any inconvenience to Calistoga residents and will continue to work with the local community to minimize any impacts associated with this work.
Generators were also installed at the substation last November to prevent Calistoga from losing power during Public Safety Power Shutoff (PSPS) events at that time.
However, with the new installation, it doesn’t follow that the town will be exempt from PSPS this summer.
“Because the lines leading out of the Calistoga Substation run through a Tier 2 high fire-threat area, we are unable to safely provide power to Calistoga from generators located at the substation during periods of extreme weather,” Contreras said.
However, “We are actively conducting a technical study to determine the feasibility and scope of deploying temporary generation at an alternate site in Calistoga during a Public Safety Power Shutoff event. We will continue to work with the city during this process,” she added.
Mayor Canning also said the city is working toward a solution in the event of a PSPS.
“We are challenging PG&E to mitigate for their concerns with the current substation to be used for this PSPS season as well as securing a more permanent solution,” he said.