Outage Possible In Calistoga As PG&E Tests New Technology

CALISTOGA, CA — A small number of Calistoga customers may lose power early Tuesday while Pacific Gas & Electric Company conducts a final test on new technology designed to reduce the risk of wildfires, the utility company advised.

Between the hours of midnight and 6 a.m., Tuesday, April 13, PG&E will test its Rapid Earth Fault Current Limiter —REFCL — as part of a pilot project at the Calistoga substation, PG&E Spokesperson Deanna Contreras said.

"Although PG&E does not foresee any disruption in customer service during the testing, it is possible an outage could occur during the scheduled times," Contreras said. "PG&E has protocols in place to ensure power is restored within 4 to 8 hours, should an outage occur. The company is asking customers to prepare for a potential outage as they normally would when a winter storm or heatwave impacts Napa County."

The city of Calistoga apologized for advising the public earlier Monday that the potential outage may occur between 9 a.m. and 4 p.m. Tuesday.

"The planned potential PG&E Power Interruption scheduled will only affect a small number of properties, and those property owners and businesses have already been notified," the city said Monday night. "... If you have not been notified you should not be impacted. We apologize for any inconvenience or concern this may have caused."

ABOUT RAPID EARTH FAULT CURRENT LIMITER, OR REFCL

"As a part of PG&E’s comprehensive efforts to address the growing threat of extreme weather and wildfires across PG&E’s service area, including installing stronger poles and power lines and conducting enhanced vegetation management — we're also testing and deploying new technologies to help mitigate wildfire risk and support operational needs," Contreras said.

REFCL significantly lowers the energy below ignition levels when it detects a downed power line or vegetation contact. This final test represents another significant step toward improving the safety and reliability of the electric system in Calistoga, Contreras said.

This technology is new to North America, as part of a pilot project, and included the main system at PG&E's Calistoga substation and the many components attached to distribution poles throughout the Calistoga area over the last couple of months — all intended to mitigate wildfire risks, according to PG&E

REFCL minimizes the impact on the electric grid during a fault condition, such as vegetation contact or a downed wire, in real-time.

"While this is a pilot project, PG&E believes this technology could substantially mitigate the risk of power lines starting wildfires," Contreras said. "Based on the test results, PG&E will decide whether to install REFCL technology at other substations within the high-risk fire areas."

Watch this video about REFCL, or see more information at PGE.com.