|
|
| Fig. 1: October 2020 wildfires over California, taken from satellite. (Source: Wikimedia Commons. Courtesy of the European Space Agency) |
California has an increasing trend of wildfires every year, and power lines play a major role in igniting many of these fires. [1,2] In particular, a 2017 report by The California Department of Forestry and Fire Protection identified 12 fires with 18 fatalities that were sparked by electric power lines or distribution lines. [3] While power lines are at fault for many wildfires, wildfires are also having a significant impact on the states electrical grid; many now see power outages and fires as synonymous in the state. This report will delve into the risk of fires on damaging power lines and distribution infrastructure.
California wildfires have inundated the state with expenses related to the electrical grid. Specifically, from 2000-2016, damages from wildfires resulted in over $700 million in damages to the transmission and distribution systems, and while the specifics of what types of damage occurred varies, the cause is the same: burning of critical infrastructure. [4] Consider Northern California, where the state identified 19 fires that occurred within mile of two major transmission paths during the same time period. The threat to the power lines is imminent. A satellite image of fires in Northern California in 2020 can be seen in Fig. 1.
The state conducted a study into the threat of fires on their major transmission paths, which are those with larger populations and spread out throughout the state to ensure coverage in all areas. In total, the state analyzed 40 different transmission paths with a range of high and low voltage lines totaling over 6000 miles of transmission lines. During 2003-2016, there were 336 large wildfires along these transmission lines. [4] Wildfires near transmission lines cause the California Independent System Operator (CAISO) to cut power to those lines. In some cases, CAISO can supply power from other generation sources when certain transmission lines are being cut, but when an area only has one transmission line, they face power outages. [5] For example, Californias largest power supplier, Pacific Gas and Electric (PG&E) cut off power to 172,000 customers in Northern California to prevent more fires from igniting in 2020. Further, many residents, such as in Shaver Lake and Huntington Lake, CA, experienced outages while the Creek Fire burned nearby. [6]
CAISO data shows that the vast majority (nearly 80%) of wildfires near lower voltage lines do not result in significant impacts, and 60% of the fires near high voltage lines had no significant impact on the electric grid. [4] However, though these percentages may be higher than expected, the fires that do impact the grid can do so substantially.
Just under 10% of the fires had a major impact, which is defined as significant outages or costly changes in generation and dispatch. [4] As seen here, changing the sources of energy can be expensive; when a wildfire threatens a transmission path, CAISO can choose to shut down the line and switch to a more expensive source of generation (because the cheapest is almost always the default). These sources do not utilize the shut down transmission line, so it prevents a power outage, but it does increase cost. Even if less than 10% of the analyzed fires caused these disruptions, with over 300 fires in the period, that is still a substantial impact on the state as a whole. One example of an insurmountable disruption was that of Creek Fire debilitating the Big Creek hydroelectric project. This project includes the Helms Pumped Storage Plant, the largest pumped hydroelectricity storage facility in California, further disrupting supply. [7] Further, with an increasing number of wildfires year over year, California faces an increased threat of power outages and costs towards the electric grid.
With an expected increase in the number of wildfires, California has investigated opportunities to lessen the threat of wildfires on the electric grid. Pacific Gas and Electric (PG&E) is the largest utility company in California, and it is the company whose power lines have been identified as the cause of several major wildfires. In fact, PG&E is responsible for at least 1,500 wildfires within California. [8] However, because PG&E supplies power to much of California, the state is also highly dependent on the company. The state has proposed options to both reduce wildfires and the risk to the electric grid, including moving transmission lines to areas with a lower risk of fire, putting transmission lines underground, and asking residents to conserve energy. [9,10] There is no clear answer for how California should manage its electricity as the tradeoffs are paramount, but inaction seems questionable.
© Olivia Brown. 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] T. W. Porter, W. Crowfoot, and G. Newsom, "2017 Wildfire Activity Statistics," California Department of Forestry and Fire Protection, April 2019.
[2] P. Krishnakumar and S. Kannan, "The Worst Fire Season Ever. Again," Los Angeles Times, 15 Sep 20.
[3] M. Mohler, "CAL FIRE Investigators Determine Causes of 12 Wildfires in Mendocino, Humboldt, Butte, Sonoma, Lake, and Napa Counties," California Department of Forestry and Fire Protection, 8 Jun 18.
[4] L. Dale et al., "Assessing the Impact of Wildfires on the California Electricity Grid," California Energy Commission, CCCA4-CEC-2018,002, August 2018.
[5] "Electric Power Monthly with Data for December 2018," U.S. Energy Information Administration, February 2019, Tables 1.3.B, 1.17.B and 1.18.B.
[6] M. J. Sanchez and C. Weber, "As California Burns, The Winds Arrive and The Lights Go Out," ABC News, 7 Sep 20.
[7] D. Yurong, "Creek Fire: Water Deliveries From Dams Might Be Affected Due to Evacuations," ABC 30 Action News, 28 Sep 20.
[8] R. Gold, K. Blunt, and R. Smith, "PG&E Sparked at Least 1,500 California Fires. Now the Utility Faces Collapse," Wall Street Journal, 13 Jan 19.
[9] I. Penn, "California Expresses Frustration as Blackouts Enter 4th Day," New York Times, 19 Aug 20.
[10] D. Echeverria and N. Mishanec, "Californians Asked to Conserve Energy As Holiday Heat Wave Looms, San Francisco Chronicle, 3 Sep 20.
