Pacific Gas and Electric Company (PG&E) has shared its multi-faceted, risk-informed strategy aimed at continuing to close the gap on the remaining 10% of wildfire risk. PG&E's 2023-2025 Wildfire Mitigation Plan (WMP), submitted to California's Office of Energy Infrastructure Safety (Energy Safety), details the company's continued efforts to construct, maintain and operate its system to minimize the risk of catastrophic wildfires and help keep its customers and hometowns safe.
PG&E's WMP outlines critical layers of protection that work together to reduce wildfire ignition risk and strengthen PG&E's electric grid. These measures include system hardening with stronger poles and covered powerlines; the company's 10,000-mile undergrounding program; tree trimming and removal; inspections and repairs; and improved situational awareness. When wildfire risk is elevated, these efforts are bolstered with operational mitigations that include Enhanced Powerline Safety Settings (EPSS), and Public Safety Power Shutoffs (PSPS) under extreme conditions.
The plan also introduces new technology solutions such as partial voltage detection and downed conductor technology that build upon the operational mitigations of EPSS and PSPS. These new technologies detect potential threats to the electric grid and rapidly reduce or shut off power to help prevent wildfire ignitions.
"Our system has never been safer, and we continue to make it safer every day. Our Wildfire Mitigation Plan outlines multiple layers of protection we're using to stop catastrophic wildfires in our hometowns. We're also doing more than ever to reduce the impacts of EPSS and PSPS on our customers. We want a future where our customers don't have to choose between safety and reliability—we want both and we are working every day to make that possible," said PG&E Executive Vice President, Operations and Chief Operating Officer Sumeet Singh.
"In 2022, we continued to enhance our wildfire risk models that predict where, why and how much wildfire risk occurs during a typical wildfire season, and we're using our enhanced risk models to plan and target work and programs to provide the greatest risk reduction for our customers and our hometowns that we are so privileged to serve," added Singh
Layers of Protection
The WMP highlights several layers of protection that have proved to be effective in reducing wildfire risk. Using these tools, PG&E achieved a 99% decrease in total acres burned in High Fire-Threat Districts in 2022, compared to the 2018-2020 average.
- Undergrounding powerlines in high fire-risk areas is a permanent protection that reduces the ignition risk from overhead electric distribution lines. PG&E remains committed to undergrounding 10,000 miles in high-risk areas and plans to underground 2,100 miles of powerlines between 2023-2026. Nearly all of the undergrounding work noted in the WMP is in high-risk areas.
- Additional System Hardening projects such as installing covered conductor, stronger poles, and wider crossarms will provide long-term ignition risk reduction by improving how the grid is constructed and operated. PG&E is also installing break-away connectors at services, which de-energize customer connections when needed to mitigate ignition risk, and is de-energizing or removing idle distribution and transmission facilities with no operational needs within high fire-risk areas.
- Enhanced Powerline Safety Settings were implemented across 44,000 line-miles, including over 25,000 miles in high fire-risk areas, in 2022 and contributed to a 68% reduction in California Public Utilities Commission-reportable ignitions when enabled on primary distribution lines, compared to the 2018-2020 average. More than half of customers protected by EPSS did not experience a power outage while EPSS was enabled in 2022. However, PG&E recognizes that EPSS outages, when they do occur, are an inconvenience. Compared to the pilot period in 2021, the average outage duration on EPSS-enabled powerlines was 56% shorter in 2022. PG&E is also installing additional sectionalizing devices and animal/avian protection equipment to further reduce the impact of EPSS outages.
- Vegetation Management strategies have been adjusted based on a risk-informed approach to focus on the highest-risk locations and to help reduce both outages and potential ignitions caused by vegetation contacting PG&E's equipment.
- Inspections and Repair Efforts are informed by risk models and are part of comprehensive monitoring and data collection programs providing insight into changing environmental hazards around assets to inform mitigation actions.
- Situational Awareness Improvements include enabling artificial intelligence to process wildfire camera data and provide automated wildfire notifications. PG&E will continue using state-of-the-art weather forecasting and a comprehensive monitoring and data collection network that uses high-definition wildfire cameras and weather stations to help detect, prevent, and respond to the risk of wildfires.
- Public Safety Power Shutoffs are used as a last resort during extreme weather conditions to reduce the risk of catastrophic fire. PG&E's experienced meteorologists use cutting-edge weather models, using a network of advanced weather stations to forecast risk on a granular basis and factor in vegetation in proximity to overhead electrical lines. PG&E's goal is to continue to minimize the size and duration of any PSPS and reduce impacts to customers without increase to the risk of catastrophic wildfires.
New Technology Solutions
The WMP introduces multiple new technology solutions that are being deployed in concert with proven wildfire risk reduction programs, including the following:
- Downed Conductor Detection (DCD) technology improves PG&E's ability to detect and isolate high impedance faults—lower-current fault conditions that may not reliably be mitigated by EPSS—before an ignition can occur. PG&E plans to engineer, program and install the DCD algorithm on equipment in high fire-risk areas.
- Partial Voltage Detection Capabilities utilize smart meters to alert the control center when voltage conditions that could present an increased ignition risk are detected. This technology helps PG&E detect and locate wire-down conditions for lower-current fault conditions—which may not reliably be mitigated by EPSS—within minutes so the line can be remotely de-energized from the Control Center for faster mitigation and to reduce the amount of time a line is energized while down.
