While planting trees can help mitigate climate change, trees also pose a risk of sparking a wildfire when they’re too close to electric power lines. As a result, utilities worldwide are spending increasing amounts of money on vegetation management to keep their equipment clear of trees and plants often stressed by climate change and one strong wind away from causing a blaze.

“The challenge is that a tree can look perfectly healthy from the outside, it may even be healthy, but in the right conditions with the right amount of wind, that tree could still come down and hit a line, cause an outage, or worse yet, cause a fire,” said Joseph Lake, director at UMS Group, Inc. and program manager of the International Wildfire Risk Mitigation Consortium (IWRMC).

Southern California Edison joined with other California investor-owned utilities and Australian utilities to form the IWRMC in 2020 to create a framework for utilities worldwide to jointly combat the global wildfire threat. This forum has allowed SCE to connect with utilities to further benchmark and share lessons learned on the strategy and execution of wildfire mitigation activities. The initial five companies have expanded to 18 currently.

The IWRMC is launching its initial set of deep-dive projects, and SCE has volunteered to lead the first one, which is the study of vegetation management and hazard tree best practices.

“A hazard tree deep dive will allow us to get a better picture of how others in the industry are looking at this risk and potentially identify additional methodologies or technologies to be able to determine which trees to take action on,” said Melanie Jocelyn, principal manager of SCE Vegetation Management Strategy and Planning.

The solution may seem simple: just cut down trees too close to power lines. For some utilities, hundreds of thousands or even millions of trees are within striking distance of power lines. But for most utilities, eliminating the threat of a tree-sparked wildfire is prohibitively expensive at a time of growing cost pressures on electricity generation, transmission and distribution.

“It typically costs thousands of dollars to remove a tree. It’s not necessarily popular with the public to remove a green tree that they may perceive to be perfectly healthy,” Jocelyn said. SCE uses professional arborists to help determine if a tree has a structural defect that could lead to a fall into a power line. “Understanding more about the different ways this is being done in the industry could potentially allow us to improve the accuracy of this process through more objective measures,” she added.

Because this is a global effort, no single strategy will necessarily work for every company. Operational circumstances vary from country to country, including the scale of tree hazards, regulatory pressures and landowner conflicts.

“Best practices are different for everybody based on your local environment, your local context,” Lake said. “There are many different pieces to the puzzle, so figuring out which pieces are appropriate for a particular company at a particular time in a particular environment is our goal.”

The vegetation management deep dive is expected to last six to eight months. Then, the global consortium of 18 utilities will turn its attention to other wildfire mitigation strategies, including best practices in undergrounding power lines.

SCE is ramping up its targeted undergrounding program over the coming years based on the updated risk analysis described in its recently filed 2022 Wildfire Mitigation Plan Update. SCE has identified a subset of high fire risk areas as “Severe Risk Areas,” with attributes that further elevate the wildfire threat to lives and property. In these situations, SCE has determined that undergrounding may be needed to significantly reduce ignition risk now and in the long term.

“In 2022, SCE is incorporating additional risk analysis and other technologies into its grid hardening strategy to further reduce the likelihood of fires associated with SCE’s facilities,” said Raymond Fugere, principal manager of SCE Wildfire Mitigation Strategy. “Our ongoing mitigation research and partnership in the consortium will enable us to stay abreast of new technologies to combat wildfire threats globally more effectively.”

For more information on SCE’s undergrounding efforts, view the fact sheet.
To get more details on SCE’s wildfire mitigation efforts, visit edison.com/wildfire-safety.