PG&E's Heightened Equipment Sensitivity Wildfire Mitigation Program

In response to extreme drought and wildfire threats, PG&E adjusted the settings on some of their equipment to automatically turn off power more quickly if the system detects a problem. This heightened sensitivity allows electric lines to be de-energized much more quickly than before the program was implemented (a fraction of a second).

The three large IOUs currently employ a technology that can sense a disturbance on an energized distribution lines and turn the circuit off. If an object makes contact with an energized line, such as a tree that falls on a line as a result of high winds, or an animal chews through the line, the sensor trips the line off.

Recently, PG&E adjusted their existing sensors to address the extreme drought conditions and dry vegetation that have exacerbated wildfires across California.

These operational changes increased the sensitivity of these sensors on infrastructure located in High Fire Threat Districts (HFTD) to detect disturbances on energized lines in order to prevent wildfire ignition. The sensors automatically turn off power if the system detects contact with the line.

CPUC HFTD map: https://capuc.maps.arcgis.com/apps/webappviewer/index.html?id=5bdb921d747a46929d9f00dbdb6d0fa2

While this wildfire mitigation safety measure is not included in their 2021 Wildfire Mitigation Plans (WMP), the six IOUs will include it in their 2022 WMPs.

The outages that result from these automatic enhanced sensor settings are not Public Safety Power Shutoffs (PSPS). In contrast, IOUs provide notification of a PSPS and pro-actively shut off power. Unlike a PSPS, weather is not the only trigger of the enhanced sensors. Wildlife (squirrels, etc.) can trigger the sensor to turn off power to an energized line.

The CPUC Safety Enforcement Division (SED) is gathering information into the PG&E EPSS program and will conduct oversight of the EPSS program through monthly reporting by PG&E and monthly meetings with PG&E in order to ensure PG&E is analyzing trends and prioritizing system hardening to mitigate the impacts of EPSS.

President Marybel Batjer’s October 25, 2021 letter to PG&E President Patricia K. Poppe regarding its fast trip settings here.