PG&E uses new tech to speed up Sierra power line undergrounding
Pacific Gas and Electric is turning to new technology as it works to bury hundreds of miles of power lines across California's Sierra Nevada, a massive effort aimed at reducing wildfire risk and improving electrical reliability.
The utility is using a new machine called the Bulldog Trencher to speed up undergrounding work in Placer County and other parts of the Sierra.
PG&E says the machine can cut a narrow trench along roadways and install underground power lines more quickly than traditional construction methods.
"This piece of equipment has done more than 1,000 feet today by cutting a pretty narrow trench road where we can put our power lines," Matt Pender, PG&E's vice president of undergrounding and system hardening, said on Tuesday.
The machine is being used as PG&E works to underground more than 100 miles of power lines through the Sierra by the end of the year.
The project is part of PG&E's broader effort to move power lines underground in areas vulnerable to wildfires.
PG&E says undergrounding can nearly eliminate the risk of equipment-caused wildfires and improve reliability during severe winter weather by removing overhead lines from exposure to wind, snow and other conditions.
"This will be a different experience for customers," Pender said. "They won't have overhead power lines, so they don't have to worry about that from a wildfire perspective, and they should see improved reliability."
But undergrounding comes with a significant price tag.
PG&E estimates the work costs about $3 million per mile, prompting the utility to look for ways to reduce construction costs and speed up the process.
The company estimates the new trenching equipment could save as much as $40,000 per day.
By the end of 2026, Pender said the company expects to have undergrounded about 1,600 miles of power lines statewide, including roughly 300 miles in Placer County.
"There's a lot of work happening here, and it will continue in the future," Pender said.
PG&E says the newly installed underground power lines are expected to last at least 60 years.
