Broken PG&E tower discovered near origin of Kincade fire on The Geysers geothermal power property
A PG&E transmission line experienced problems moments before the 16,000-acre Kincade fire started inside The Geysers, a sprawling complex of geothermal energy facilities nestled in the mountains between Sonoma and Lake counties, according to a utility filing with state regulators.
Cal Fire later discovered a broken piece of equipment on a PG&E transmission tower that was not deactivated during a power shutdown initiated by the San Francisco-based utility before the fire broke out Wednesday night, the company reported in a filing with the state Public Utilities Commission.
PG&E said it became aware of a problem on a 230-kilovolt transmission line running through The Geysers at about 9:20 p.m. Wednesday. The fire was first reported at 9:26 p.m., when firefighters were sent to a vegetation fire in The Geysers on John Kincade Road at Burned Mountain Road near a small power plant, according to dispatch reports.
A time-lapse video from a fire detection camera near Santa Rosa captured the ignition of the fire. In the ALERTWildfire video, a steady light in the hills near The Geysers abruptly blinks out at 9:20 p.m., followed instantly by a ball of flames that rises on the horizon and begins sending a plume of smoke billowing to the west.
PG&E shut down power to some 27,000 customers in Sonoma County on Wednesday, part of its plan to prevent its equipment from sparking wildfires during hot, dry, windy conditions that can cause flames to spread rapidly. It began restoring power in Sonoma County on Thursday after the winds subsided, but anticipates dangerous fire conditions will return this weekend and could lead to another round of blackouts.
PG&E said it cut the power to local distribution lines in Geyserville and the surrounding areas - but not the larger transmission lines that carry power across the state.
“Those transmission lines were not de-energized because forecast weather conditions, particularly wind speeds, did not trigger the (public safety power shut-off) protocol,” PG&E said in a statement. “The wind speeds of concern for transmission lines are higher than those for distribution.”
The tower in question was inspected earlier this year as part of the utility’s efforts to prevent wildfires, PG&E said in a statement Thursday evening.
The broken equipment at the tower will become part of investigations by state fire officials and utility regulators to determine what role, if any, PG&E equipment played in the wildfire.
“Cal Fire determines the sources of ignition of fire and the way that the fire spreads. The CPUC is conducting a staff investigation to assess the compliance of the electric facilities with applicable rules and regulations,” said Christopher Chow, a Public Utilities Commission spokesman. “Our hearts go out to those impacted by the fire, and we continue to work with our partner state agencies that are on the front lines.”
Initial dispatch reports warned firefighters to be aware of “possible power lines down in the area.” By 9:53 p.m., firefighters knew they would not be able to contain the wind-whipped fire and needed to start evacuations, the radio traffic indicated.
Calpine Corp., which operates the largest power facilities in The Geysers, does not believe its equipment caused the Kincade fire. As a result of windy conditions in the area, The Geysers de-energized its local power line system before the fire broke out, Calpine spokesman Brett Kerr said. The decision was “consistent with our fire prevention protocols,” he said.
“We do not believe our facilities caused the fire,” he said. “There are power lines operated by third parties across The Geysers.”
Firefighters had not determined Thursday whether the blaze was ignited by power lines, Cal Fire Battalion Chief Marshall Turbeville said. State investigators typically take months to pinpoint the cause of major fires and announce their findings.
Turbeville said he had heard that a building could be involved, but there wasn’t enough information yet to know exactly how the fire started - and whether it originated from the building or the power lines, or started elsewhere and overtook them as it spread.
The Geysers is a geothermal power operation on 45 square miles in the remote Mayacamas Mountains above Healdsburg and Geyserville. It includes more than a dozen individual power plants, mostly in northern Sonoma County, with a few in Lake County, that comprise the largest geothermal energy facility in the world.
Houston-based Calpine Corp. produces enough electricity to power more than 700,000 homes from its plants on the property. High-voltage power lines carry electricity generated by its steam turbines out to the region’s grid, cutting a path through the rugged Mayacamas Mountains.
“The Kincade fire flashed through a portion of our Geysers geothermal facilities late yesterday,” Kerr said. “All employees are safe and accounted for. We believe there is relatively minor damage to our facilities and further threat has passed. As safety permits we will conduct a thorough assessment. Some of our operations have been temporarily suspended but we expect production will resume very soon.”
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