Photo by PG&E.
PG&E conducted multiple BurnBot tests in varied terrain in 2023 and plans to expand its testing in additional settings in 2024.

Layers of Protection Can Reduce Wildfire Risk

June 17, 2024
PG&E deploys a remotely operated controlled-burn system, next-gen drones, wireless remote grids and more to enable layers of protection.

Pacific Gas & Electric Co. (PG&E) is deploying innovative and emerging technologies, including a remotely operated controlled-burn system, next-generation drones and wireless remote grids, building on the proven layers of protection that reduced wildfire risk from its equipment by 94%, based on established methodologies, to help keep its customers and hometowns safe.

“Our system has never been safer, and we continue to make it safer every day. We’re prepared with multiple layers of protection and innovative new technologies to mitigate catastrophic wildfires in our hometowns. 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 Sumeet Singh, PG&E executive vice president and chief operating officer.

Neither Overhead, Nor Underground

With ground-level distribution systems (GLDS), power lines are neither suspended from utility poles nor buried underground. Instead, lines are placed inside protected and resilient conduits that rest on the ground. PG&E is exploring moving overhead power lines to ground level to eliminate ignition risk and enhance grid resilience. GLDS packages electric cable in conduit in a specially molded tray, tied in with a basalt rebar, then sealed with a special geopolymer cement, placed at ground level and capped in thermoplastic.

PG&E reached a significant milestone as a half mile (0.8 km) of GLDS circuit was energized in November 2023 in San Mateo County, California, U.S., as the first-in-the-world installation and energization. The utility anticipates this innovative approach could provide comparable risk reduction to undergrounding.

Fighting Fire with Fire

PG&E is testing BurnBot as an alternative to traditional land management techniques (such as using herbicides or mowers) around its facilities to clear vegetation, explore potential environmental and safety benefits, and determine opportunities to scale. BurnBot offers a remotely operated, controlled-burn technology to manage landscapes and burn woody materials on-site to reduce environmental and safety issues associated with controlled burns.
PG&E conducted multiple BurnBot tests in varied terrain in 2023 and plans to expand its testing in additional settings in 2024.

Next-Gen Drones

Automated and beyond visual line-of-sight drone operations in collaboration with Skydio are helping to augment manually operated drone asset inspections and provide a fast, safe and effective solution for field validation of a range of sensor alerts.

PG&E first began using drones in detailed electric transmission infrastructure inspections in 2015, but significantly ramped up its usage by 2020, after finding drone-based inspections to be more efficient and productive.In 2022, the utility began using unmanned aircraft systems (UAS) technology to perform gas pipeline leak surveys on 16 miles (26 km) of water crossings traditionally done by boat.

Then in 2023, working with Skydio, PG&E became the first utility in California to begin conducting fully remote drone operations for electric system inspections after receiving a waiver from the Federal Aviation Administration to operate drones beyond the visual line of sight for a variety of inspections, providing a threefold advantage of increased system, operator and community safety; reduced time and resources; and cost savings.

PG&E recently expanded its UAS applications beyond inspections, becoming the first utility in North America to string power lines with drones, working with Infravision. The utility began using Infravision’s TX UAV stringing system to string power lines in 2022 and has used the system more than 20 times, largely to repair sections of its overhead electric distribution grid damaged by winter storms but also to proactively reconductor higher-voltage transmission lines.

The TX system can be deployed in areas and conditions where helicopters cannot fly, including for service restoration in difficult terrain during and after storms and for reconductoring projects in highly complex urban and suburban environments.

Wireless Remote Microgrids

In November 2023, leaders from PG&E, Pepperwood Foundation, BoxPower Inc., Sonoma Clean Power, Franklin Energy and the California Public Utilities Commission gathered with regional, state and federal stakeholders at Pepperwood Preserve in Sonoma County to commemorate the first fully renewable remote grid deployed in PG&E’s growing fleet of stand-alone power systems.

Throughout PG&E’s 70,000-sq-mile (181,299-sq km) service area, remote customers are served via long electric distribution lines that traverse high-risk fire areas. Replacing these distribution lines with a remote grid is an innovative option that can cost-effectively meet customer needs and reduce fire ignition risk.

The fully renewable remote grid at Pepperwood replaces 0.7 miles (1.1 km) of overhead distribution line, eliminating the associated wildfire risk. The remote grid at Pepperwood will be PG&E’s fifth operational remote grid since 2021.Collectively, PG&E’s five remote grids enable 10 customers to continue receiving safe, reliable, affordable and low-carbon energy while removing approximately 5 miles (8 km) of overhead distribution electric lines at the grid edge in high fire-threat districts. The utility has identified many locations where remote grids may be the most effective way of reducing wildfire risk and improving electric reliability, with additional sites either in development or being assessed in Madera, Shasta and Tehama counties, among others.

PG&E plans to scale its remote grid fleet to dozens of systems over the next several years, leveraging New Sun Road’s Stellar Microgrid OS as the remote monitoring and control platform. The Stellar platform enables the utility to monitor and control remote grids via satellite and cellular connectivity, with capabilities for remote performance management, safety diagnostics, alarms, reporting and automated refueling notifications. Remote grids also feature an integrated fire-suppression system to protect the hardware and facility.

Easy-Connect Backup Power

PG&E has successfully developed a first-of-its-kind personal backup power transfer meter device for customers that fully integrates into the utility’s existing electric SmartMeter system. The device provides customers with a safe, easy-to-use and more reliable solution for interconnecting backup power sources, such as portable generators, batteries and qualified electric vehicles, to power essential devices and appliances during a power outage.

The utility has installed more than 1,500 backup power transfer meters for customers in high-risk fire areas since 2022 and plans to install thousands more through 2025. PG&E demonstrated using the onboard generator of an all-electric Ford F-150 Lightning to power devices through the backup power transfer meter.

Detect a Fault, Cut Off Power

PG&E’s enhanced power line safety settings (EPSS), which shut power off in one-tenth of a second or less when contact with a foreign object or a fault occurs on a power line, reduced ignitions by 68% in 2023 in the utility high-risk fire areas. Building on the operational mitigations of EPSS, PG&E is also deploying additional layers of operational mitigations, including new downed conductor and partial voltage detection technology, to detect potential threats to the electric grid and rapidly reduce or shut off power to help mitigate wildfire ignitions.

Downed conductor detection (DCD) technology improves PG&E’s ability to detect and isolate high-impedance faults — lower-current fault conditions that may not be mitigated reliably by EPSS — before an ignition occurs. The utility is engineering, programming and installing the DCD algorithm on equipment in high-risk fire areas.

Partial voltage detection capabilities use SmartMeters to alert PG&E’s control center when voltage conditions that could present an increased ignition risk are detected. This technology helps the utility to detect and locate wire-down conditions for lower-current fault conditions — which may not be mitigated reliably by EPSS — within minutes, so the line can be deenergized remotely from the control center for faster mitigation and to reduce the amount of time a line is energized while down.

A Moonshot for Detection

Detect and suppress a high-risk wildfire in 10 minutes or less. Pinpoint all fire ignitions across multiple states or countries from space within 60 seconds. These are the challenges for innovators of XPRIZE Wildfire, a four-year, US$11 million competition aimed at developing innovative technologies to improve the detection and suppression of destructive wildfires. As co-title sponsor, PG&E believes this competition will be a game changer.

About the Author

Paul Doherty

Paul Doherty is a principal communications representative at Pacific Gas & Electric Co. Doherty leads PG&E's public relations strategy around innovation and emerging technologies including microgrids, battery energy storage, drones, artificial intelligence, data analytics, vehicle-grid-integration, virtual power plants, technology partnerships and R&D, which are all key to building a stronger, more resilient and more sustainable energy grid.

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