Powerline Safety Settings and Continued Focus on Tree Work Helping PG&E Reduce Risk of Ignitions and Wildfires

Every day, PG&E is making the electric system safer and stronger for our customers. Using advanced technologies and rebuilding the electric system from the underground up, we are preventing wildfires, improving reliability and reducing costs over the long term.

As we shared with the Wall Street Journal, PG&E has increased our investment in wildfire mitigation efforts by $2 billion over the last five years (from $3.8B to $5.5B). We develop and implement our wildfire mitigation programs based on the best information and data that we have at the time, and our capabilities have continued to evolve and mature since 2019.

To be clear, the essential work of our trained PG&E vegetation-management inspectors and our contract vegetation-management crews to keep trees away from powerlines will continue. Every day, we have more than 5,500 employees and contractors on the job throughout our Northern and Central California service area doing the work to keep trees and limbs from coming in contact with our powerlines.

About EVM and the emergence of EPSS

In 2019, our understanding was that Enhanced Vegetation Management could be an effective risk reduction measure, based on the best information at the time, which was the CPUC’s and CAL FIRE’s High Fire Threat District (HFTD) map. For distribution, one of the predominant failure modes was vegetation coming into contact with our overhead lines. As a result, we expanded our vegetation management efforts beyond the existing regulations. As we operationalized EVM, we realized we needed to evolve to engineered controls (Enhanced Powerline Safety Settings), because we cannot identify every tree that may pose a risk.

As we have continued to evaluate each measure’s effectiveness, and with the rapid evolution of technology and innovation, we have successfully  implemented the new mitigations. Several new mitigations are now in place and more in-depth risk modeling allows us to target resilience efforts more effectively. Based on these improved capabilities, we have evaluated each layer of risk mitigation to ensure we deliver the maximum wildfire risk reduction at the lowest possible cost to our customers. To this end, our 2023-2026 General Rate Case revised proposal is aligned with these improvements which reduces our planned Vegetation Management spend in favor of more effective and permanent risk mitigation measures.

As part of our layers of wildfire protection approach, our operational mitigations including EPSS have been effective in reducing vegetation-related ignitions. EPSS is a proven wildfire prevention tool. In 2022, we saw a more than 68% reduction in CPUC-reportable ignitions on EPSS-enabled circuits in HFTD. If ignitions occur, the size of the fires are much smaller thanks to EPSS. In 2022, there was a 99% decrease in acres impacted by ignitions (as measured by fire size from electric distribution equipment compared to the 2018-2020 average) despite dry conditions.

With EVM, the electricity flowing through the powerlines was not impacted in any way. However, EPSS cut power in less than one-tenth of second when a fault occurs,  which reduces the size of an ignition should it occur. By stopping ignitions, we help prevent fires from starting and spreading.

About our Community Wildfire Safety Program

Our wildfire prevention work relies on layers of wildfire protection to make our system safer and more resilient while positioning us to better serve our customers in the short and long term and respond to our state’s evolving climate challenges.

Here are some examples of our layers of wildfire protection:

• Our 10,000-mile Undergrounding Program is the largest effort in the U.S. to underground powerlines as a wildfire risk reduction measure.
• In addition to undergrounding, we are strengthening the electric system with stronger poles and covered powerlines in and near high fire-risk areas.
• Enhanced Powerline Safety Settings (EPSS) decrease ignitions and provide wildfire protection to all customers living in high fire-risk areas.
• We continue to reduce the impact of Public Safety Power Shutoffs (PSPS). While there were no weather-driven PSPS outages in 2022, it continues to be a top focus for our team.
• We are managing trees and other vegetation located near powerlines that could cause a power outage and/or ignition.
• We are also investing in advanced tools and technologies like artificial intelligence and drones that help us automate fire detection and response.

More about PG&E’s Vegetation Management programs

To be clear, the essential work of our trained PG&E arborists and our contract vegetation-management crews to keep trees away from powerlines will continue.

Our 2023 vegetation management approach will increase total risk reduction by focusing investment on programs to enable permanent risk reduction and more efficient operational mitigations.

This work involves:

• Pruning trees to meet or exceed state vegetation and fire safety standards
• Cutting down dead, diseased or dying trees
• Evaluating the condition of trees that may need to be addressed if they are tall enough to strike powerlines or equipment
• Pruning or cutting down trees and shrubs to increase defensible space or constructing stronger, more resilient electric equipment
• Additional safety work to address vegetation near electric equipment or gas lines.

Our routine Vegetation Management Program:

• Inspects more than 80,000 miles of overhead powerlines every year, with some locations patrolled multiple times a year.
• Prunes or cuts down more than 1 million trees annually to maintain clearance from powerlines.
• Cuts down dead, diseased or dying trees, primarily in areas affected by drought and bark

In 2023, we are restructuring our VM Program based on a risk-informed approach.  Recent data and analysis demonstrate that the EVM Program risk reduction is less than EPSS and additional operational mitigations such as Partial Voltage Detection capabilities. As a result, we transitioned the EVM Program to three new risk-informed VM programs:

• Focused Tree Inspections: We developed specific areas of focus (referred to as Areas of Concern, primarily in the HFRA, where we will concentrate our efforts to inspect and address high-risk locations, such as those that have experienced higher volumes of vegetation damage during PSPS events, outages, and/or ignitions.
• VM for Operational Mitigations: This program is intended to help reduce outages and potential ignitions using a risk-informed, targeted plan to mitigate potential vegetation contacts based on historic vegetation-caused outages on EPSS-enabled circuits. We will initially focus on mitigating potential vegetation contacts in circuit protection zones that have experienced vegetation-caused outages. Scope of work will be developed by using EPSS and historical outage data and vegetation failure from the WDRM v3 risk model.
• Tree Removal Inventory: This is a long-term program intended to systematically work down trees that were previously identified through EVM inspections. We will develop annual risk-ranked work plans and mitigate the highest risk-ranked areas first and will continue monitor the condition of these trees through our established inspection programs.

Regarding the prior marked trees as part of EVM, we are mitigating the trees in a risk-informed manner, focused on mitigating the highest risk trees starting in 2023. The initial plan estimates mitigating the known marked trees of ~385K over the course of nine years. This pace is continually evaluated to determine if the work can be completed sooner than planned. Additionally, as part of our annual vegetation management program, we inspect, twice a year, the trees that remain in place until they are scheduled to be mitigated.  If an inspector identifies a marked tree that presents a hazard (the condition of the tree has worsened) during any inspection, that tree is prioritized for mitigation.