|
|
| Fig. 1: Utility-caused wildfires and its percentage of the total wildfires in California between 2016 and 2020. [6] (Source: S Chunduru) |
Utilities have caused the most destructive wildfires in California over the past decade. To mitigate the threat of wildfires, utility companies have deemed Public Safety Power Shutoff (PSPS), which entails turning off power during severe weather, as necessary. However, loss of power during PSPS events adversely impacts customers. Improvements to the electrical grid are critical to mitigate the risk of utility-caused wildfires since PSPS events are disruptive and not a long-term solution.
The area burned by wildfires in California has increased dramatically over the past 20 years. [1] Eight of California's top ten wildfires have occurred in the past five years, including the Thomas Fire in 2017 and the Dixie Fire in 2021. In 2020, wildfires burned 4.2 million acres, more than double the number than in any other year on record. [1] Rising temperatures, drought, and strong winds in California will continue to increase the incidence of wildfires as well as the magnitude of the resulting damage.
|
||||||||||||||||||||||||||||||||||||||||||||||||
| Table 1: Most destructive utility-caused wildfires from 2000 to 2021. [2] |
 |
| Fig. 2: Emergency Fund Suppression Expenditures (all wildfires) from 1980 to 2021 [3] (Source: S Chunduru). |
Fig. 1 shows that on average, utility-caused wildfires accounted for approximately 10 percent of all Cal Fire-reported wildfires from 2016 to 2020. Table 1 shows the seven most destructive utility-caused wildfires in CA from 2000 to 2021, with the 2018 Camp wildfire being the most destructive in terms of structures destroyed, and deaths caused. [2] Cal Fire spent $1.23 billion during the 2020-21 fiscal year to suppress all wildfires in California, including utility-caused wildfires, a steep increase from previous decades, as shown in Fig. 2. [3] While the cost of extinguishing large wildfires is growing, it only represents a small portion of the overall costs related to a wildfire incident. An analysis by Wang of the economic costs of wildfires in 2018 found that the estimated $148.5 billion in wildfire damages in California in 2018, included capital losses of $27.7 billion, medical expenses of $32.2 billion, and indirect losses of $88.6 billion. [4] Additionally, wildfires accounted for 52% of indirect losses outside of California (31% of total losses). [4]
To prevent wildfires caused by high winds that cause tree branches and debris to come in contact with energized lines, utilities are using Public Safety Power Shutoff (PSPS) as a mitigation tool. However, the PSPS incidents have created serious hardships for the community, especially those who rely on medical equipment at home and those who face food insecurity without refrigeration. To reduce the need for PSPS events and prevent the risk of utility-caused wildfires, utilities must invest more in enhanced vegetation management and improvements to the electrical grid.
Improving Vegetation Management: Between 2015 and 2020, the biggest utility companies in California estimated that at least 24 percent of fires they caused were started when trees and other vegetation came into contact with their equipment. [5] To maintain a safe distance from power lines, trimming and removing trees and other vegetation can help reduce the likelihood of utility-induced wildfires, thereby reducing the need for PSPS.
Improving the Grid:
Covered power lines - In California, 27 percent of the power lines, or more than 74,000 miles, are situated in locations where there is a significant risk of fire, and at least 54 percent of these power lines are bare lines. [5] Covering power lines with insulating material can be extremely successful at preventing dangerous ignitions in windy circumstances. [5] Investing in covered power lines can significantly reduce utility-induced wildfires and the need for PSPS.
Moving power lines underground is considered one of the best ways to reduce the risk of utility-induced wildfires, but it is expensive to implement. According to the U.S. Energy Information Administration, underground power lines cost 5 to 10 times as much as overhead distribution lines. [5] Investing in underground power lines is a costly but effective means for mitigating utility-induced wildfires and eliminating the need for PSPS.
Distributed Energy Resources - Residential solar and storage, microgrids, and sectionalizing devices can reduce the scope of PSPS outages. In the event of a wildfire, utilities can disconnect microgrids from the main grid and allow them to operate independently to power critical infrastructure. Sectionalizing devices can be used to divide the electric grid into smaller sections to reduce the scope of PSPS outages by de-energizing targeted areas to reduce wildfire risk.
During the time when utilities try to catch up with grid maintenance and infrastructure improvements, the threat of wildfires will continue to cause PSPS outages. While utilities are working to reduce the frequency and duration of PSPS events, these outages will continue to plague California for the foreseeable future. In the longer term, grid modernization and distributed energy, especially residential solar and storage, will play a key role in wildfire resilience and in shaping the future of the power industry.
© Sohan Chunduru. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] L. Zeise et al., "Indicators of Climate Change in California, 4th Ed.," California Environmental Protection Agency, November 2022.
[2] "Top 20 California Wildfires," California Department of Forestry and Fire Protection, October 2022.
[3] "Emergency Fund Fire Suppression Expenditures," California Department of Forestry and Fire Protection, 28 Oct 22.
[4] D. Wang et al., "Economic Footprint of California Wildfires in 2018," Nat. Sustain. 4, 252 (2021).
[5] "Electrical System Safety: California's Oversight of the Efforts by Investor-Owned Utilities to Mitigate the Risk of Wildfires Needs Improvement," Auditor of the State of California, Report 2021-117, March 2022
[6] "Wildfire Activity Statistics," California Department of Forestry and Fire Protection, 2016, 2017, 2018, 2019, 2020.