Tuesday, February 8, 2022

Battling Wildfires

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EPRI’s research aims to improve prevention of and response to wildfires and other extreme weather events

The California Department of Forestry and Fire Protection (CAL FIRE) is a clearinghouse of information about wildfire events and trends in the state. In recent years, summaries of wildfire seasons have been similar to this description of 2020: “The 2020 California wildfire season was characterized by a record-setting year of wildfires that burned across the state of California as measured during the modern era of wildfire management and record keeping,” the department wrote.

Indeed, 2017, 2018, and 2020 were all record-setting wildfire seasons, as measured by acres burned, number of fires, structures damaged or destroyed, and lives lost. Wildfires are by no means a problem faced only by California. According to the National Interagency Fire Center, over 46,000 fires burned more than 7.5 million acres across the United States in 2020.

Wildfires are a significant challenge in a growing number of states across the country, particularly as climate change leads to warmer temperatures and longer droughts. For utilities, the challenge posed by wildfires is both large and complex.

“There is clearly an urgency on the part of utilities to understand and to implement approaches that reduce wildfire risks. These implementations are complex because sometimes they relate specifically to utility ignition incidents and other times they are associated with damage and other impacts to the power infrastructure,” said Doug Dorr, an EPRI technical executive who is leading research to help utilities prepare for and respond to wildfires and other extreme weather events. “The number one utility objective is public and worker safety. When you think about that, it means that the first thing you do is implement designs and technologies that minimize the risks of ignitions happening in the first place.”

EPRI has a long history of research into technologies and techniques to improve grid resilience against extreme weather. In fact, EPRI was founded in the wake of a weather-related blackout that hit the northeastern United States and Ontario, Canada, in 1965.

Preventing wildfires from starting is a focus of EPRI’s research, testing, and pilot and demonstration projects with member utilities. EPRI’s work involves mechanical, electrical, and lifecycle performance testing. Preventing grid infrastructure from igniting fires—and avoiding customer outages caused by wildfires—are big priorities for utilities. But it’s important to remember that utilities alone can’t prevent wildfires, which is why improving wildfire response is also so critical. “Even if utilities were perfect at preventing ignition events that start fires, it would impact the number of fire starts by less than 10 percent,” said Dorr. “Not that many fires are started by power systems.”

Indoor and Outdoor Lab Testing

In June 2019, EPRI launched a three-year grid safety and resilience initiative aimed at helping utilities to plan, design, and operate their power systems in the face of extreme weather and wildfire events. The initiative involves a mix of equipment testing at EPRI’s facility in Lenox, Massachusetts, and field demonstrations with member utilities. The ultimate goals of the work are to help utilities design their grids to be as resilient as possible; to test equipment able to withstand extreme weather; to optimize utility response to and recovery from natural disasters; and, whenever possible, to avoid or reduce the impacts of weather-related outages.

Maximizing grid resilience against wildfires and other extreme weather events requires using equipment that can withstand years of exposure to harsh weather. At EPRI’s Lenox laboratory, grid equipment such as covered conductors, connectors, and insulators are placed in a customized environmental chamber. Equipped with ultraviolet lights, high-voltage electricity, and the ability to expose assets to salt fog, the aging chamber accelerates the normal aging process of equipment threefold, meaning three years in the chamber is like a decade under normal conditions.

The facility also includes an outdoor test yard, where equipment is exposed to extreme electrical and physical stresses. For example, researchers utilize Mylar balloons and vegetation to replicate the arcs and sparks that can ignite wildfires. The aim of these tests is to better understand the lifecycle performance of different products and to compare the resilience of similar products made by different manufacturers.

EPRI works directly with member utilities to test these products and to vet new grid equipment a utility is considering using. Improved knowledge about how conductors, insulators, and other equipment function under extreme weather conditions helps utilities guide important investment decisions. “Ideally the equipment needs to last the life of the system, which in some cases might be 40 or 50 years,” said Dorr. “You can’t go back in 10 years and spend $2 billion to redo it because you didn’t get it right the first time.”

Another component of the research is to evaluate designs of distribution and transmission grids for resilience. One way to help prevent wildfires is to design transmission and distribution poles to ensure they remain intact so that the lines stay in the air. “Generally, a resilient design takes the half dozen force-bearing components and goes through each one to make sure the weak link is not the pole,” said Dorr. “You can create a design where the force goes to components you want to break and not to the ones you know are time consuming and costly to repair if they do break.”

Wildfire by power lines

Helping to Develop and Test New Technologies

As the task of preventing and responding to extreme weather events becomes more challenging, utilities are exploring ways technology can improve grid resilience. EPRI assists in that effort by helping to evaluate new technologies. “EPRI’s primary role in this space is to look at the emerging technologies and to use our network of experts to do the initial vetting to see if there is an opportunity to try it out in the extreme weather or wildfire space,” said Dorr. Technologies that prove to have potential can then be tested in the field with the help of member utilities.

There is a meaningful pipeline of technologies that either are already available to utilities or show promise. For example, as part of EPRI’s Incubatenergy program, which works with startups whose products and services could benefit the utility industry, Dorr is collaborating with San Francisco-based Pano AI. The company has developed high-definition, 360° cameras that can be installed on transmission towers and other elevated observation points. Historically, cameras used to monitor utility grid infrastructure have only provided a view in one direction and didn’t have the benefit of algorithms to evaluate images and trigger alerts at the first sign of fire.

“These new cameras run AI algorithms that can filter out fog and clouds and other false positives and pick out smoke in near real time as a fire starts,” said Dorr. “Utilities can overlay the platform Pano AI has created over their system and they know if smoke is from their system, how close it is to transmission lines, and whether to shut the lines down if the fire gets too close. The camera is the tool and the AI is the enabler that allows you to react fast to provide first responders with a greater chance of keeping the fire from spreading.”

Technology can also help improve the accuracy and efficiency of the transmission and distribution line inspections that help identify trees and vegetation at risk of falling and igniting a fire. One EPRI project is investigating how satellite imagery can be used to identify vegetation that should be trimmed or dead trees and dry leaves that provide the fuel that can accelerate a wildfire. “We can use satellite imagery to look at the chlorophyll levels of pine trees or leaves of trees, and by looking at that spectrum you can see if they are healthy or dying and whether they are a risk or not,” said Dorr. “That can be more cost efficient than walking the lines and can help to identify at-risk vegetation just beyond the rights of way, where inspections don’t go.”

EPRI also works with utilities to evaluate flame-retardant materials that can help protect utility poles. For example, an increasing number of utilities are wrapping wooden poles with an intumescent covering that will burn when exposed to flames but keep the actual pole safe from damage. EPRI’s role is to be an independent third-party validator of manufacturer claims and to improve understanding of how these materials perform after aging and under environmental stresses.

SDG&E’s Approach to Wildfires

Because of the increasing frequency and intensity of wildfires, California utilities are especially proactive about deploying advanced technologies and products to prevent and respond to the threat. San Diego Gas & Electric (SDG&E), for example, has implemented or is in the process of incorporating a wide range of new technologies and approaches to address wildfires.

For example, a wildfire can be caused if an energized power line is severed and hits dry vegetation on the ground. SDG&E uses technologies that determine when a conductor has broken and instantly cut the power before the line reaches the ground.

SDG&E has also become the first utility in the country to build its own weather network. The network provides the utility with updated weather data every 30 seconds, and SDG&E has augmented it with cameras able to measure the chlorophyll in vegetation and sensors that assess the moisture levels in brush. In addition, SDG&E is using satellites to monitor wildfire activity and is increasing its use of drones to evaluate grid infrastructure in areas facing high fire risks.

Not all of SDG&E’s fire prevention methods are high tech. The utility is also relying on goats to eat grass near power lines, thereby removing fuel that can burn in a wildfire.

When this current phase of research is completed next year, EPRI will work with other utilities to help share findings and lessons learned. But Dorr doesn’t expect research to help utilities navigate wildfires and other extreme weather events to end anytime soon. “I don’t see this going away, and we will address this for the long term, just like we have been addressing hurricanes and ice storms,” said Dorr. “We will continue this kind of research as long as we have challenges with resilience on the grid.”

Resilience and Awareness

The scope of wildfire-related activities currently taking place is wide and is strongly influenced by the unique conditions each utility faces. “What it comes down to for utilities is continuous improvement in risk reduction and resilient design,” said Dorr.

Because of that, EPRI’s research in the transmission and distribution space largely falls into two broad categories. “The first is resilient infrastructure and right of ways, which covers everything we can do to reduce the risk of ignitions and of system impacts from wildfires,” said Dorr. The second is geared towards accelerating awareness. “That covers leveraging of everything from weather and smoke to power flow sensors to help predict what might happen before it actually does,” said Dorr.

Key EPRI Technical Expert:

Doug Dorr
For more information, contact techexpert@eprijournal.com.