The Pacific Gas and Electric Company on Wednesday responded to more questions from U.S. District Judge William Alsup on Bucks Creek in the 1101 circuit suspected of causing the Dixie fire in July.
Alsup continues to pressure the company on why it did not turn off the entire line on the morning of July 13 when the line was without electricity. In response on Wednesday, the company added to Alsup’s question in mid-November that at least one insurance had burned out at 2:43 p.m. what caused it or what could be the cause? And could it be reasonable to stop the electricity because of this?
The company said the operator was a student driven by an experienced operator who listened to a phone call at 2:53 p.m. that day.
In that phone call, Dixie told the operator that the problem was that he had seen at least one open insurance, but still could not get insurance. A more experienced operator thought that the cause of the power outage was an open insurance situation described by Dixie Problem, while the litigation operator was called №3.
The operator, however, said he did not know the cause of the open insurance situation, but he told the court that in his experience, the operation of one or more fuses was a common occurrence and that was not a reason to deactivate the line on its own. turn off the power to all users.
According to the application, “The operation of the fuses is designed to eliminate faults by preventing the current from flowing down the source in the conductors experiencing faults. There are a number of possible causes, among which the most common malfunctions are birds, squirrels, tree branches falling, contact with trees, wind lines crashing into each other, and other similar phenomena.
The company also said that at about 2:00 p.m., when Operator 2 informed it about the line, which was about an hour before it called for a fault, Operator 3 did not see any signs of a ground fault or malfunction in real time. anything in the data that indicates a reason to weaken the entire line.
In mid-November, in response to Alsup’s question about Bucks Creek 1101 Circuit being ranked 11th out of 3,635 schemes in terms of equipment risk, the company said it found that the line was on fire about seven months before the fire. the need for hardening.
This work was to begin in 2022.
According to the company’s report, the 2021 model that provided the rating is related to power transmission lines that cover a distance of about 25,000 miles in areas with a high risk of fire, spread and level 3 fires. evaluates the consequences associated with equipment failure. 2.
According to the application, “The Hardware Risk Model consists of two sub-models: one generates the probability of combustion (” POI “) as a result of equipment failure and the other mimics the effect of combustion (” Wild Fire Consequence “).”
The company claims that these are components of the forest fire risk formula: Wild fire risk burning times are equal to the consequences of forest fires.
“The combustion probability for each CPZ was obtained using a machine study regression model to study a number of covariances or variables associated with PG&E’s high-distribution conductors, as well as the environmental and weather conditions in a particular area where the conductor is located. historical combustion events to generate a relative rate of occurrence, i.e., the probability of combustion.
According to Bucks Creek 1101 PG&E, it has a combustion index of 181, which means that the average precipitation is low, the copper conductor material is used in the line, and the probability of failure compared to other conductor materials is high. said it had this rating because it was. maximum tree height in the segment.
The company also noted that the size of the 44-year-old conductor was also a factor.
Due to the 2021 risk level, PG&E has identified Bucks Creek 1101 as a priority to strengthen the system and quickly began to develop a plan to tighten this scheme, which was approved in January 2021.
But the company also said the project is scheduled to begin construction in 2022 due to a variety of factors, including weather and dependence on several agencies (including railroad, Caltrans, U.S. Forest Service, Cal Fire and local counties).
To assess the effects of wildfires in the 2021 model, the company uses the “Technosylva fire modeling simulation program to assess fire spread on the basis of fire spread rate, flame length and fire movement index; The 8-hour fire simulation (with off) on estimated acres of fire, affected structures, and population is based on estimated fuel conditions and historically elevated fire weather conditions.
The company says it will take these “natural units” and convert them into multi-attribute value function points under the company’s 2020 Risk Assessment and Mitigation Phase Report and the 2018 Security Model Assessment Agreement.
The result of this simulation rated the area occupied by Bucks Creek 1101 as 3512 multi-attribute function scores, which ranked 200th, which is that the rising acres burned and the fire action index score.
The company said the overall risk level was calculated by multiplying the Fire Probability (0.000265) by the Wild Fire Consequences (3,512) to create a total risk level of 11 (from the 3635 scheme segment) in the 2021 Equipment Risk Model.
