Crews Safely Complete Construction, Energization of 350 More Miles of Underground Powerlines in 2023

By Matt Nauman

As of this week, PG&E has constructed and energized more than 600 miles of underground powerlines since its ambitious 10,000-Mile Undergrounding program started in mid-2021.

And the 350 miles completed in 2023 represents the most ever in a single year by PG&E and nearly twice as many miles as were completed in 2022.

“Our customers in high fire-risk locations where we have undergrounded powerlines not only benefit from wildfire mitigation but also improved reliability at the lowest cost over the asset lifecycle,” said Peter Kenny, PG&E’s senior vice president of Major Infrastructure Delivery, which includes the 10,000-mile Undergrounding program. “That progress will continue in the years ahead.”

From $4 million per mile when the program first started, PG&E targeted cost reductions to $3.3 million per mile by this year. In fact, the unit cost has now fallen below $3 million per mile.

Eliminating risk with layers of protection

Undergrounding eliminates nearly 98% of the risk of wildfire ignition from electrical equipment. And it’s one of many layers of wildfire protection from PG&E, ranging from 600-plus weather stations and high-def cameras with AI capability for early fire detection to safety shutoff programs that prevent ignitions that could lead to catastrophic wildfires.

The undergrounding program was launched in June 2021 by PG&E CEO Patti Poppe. PG&E and contract crews completed 73 miles that year, 180 miles in 2022 and 350 miles this year.

The California Public Utilities Commission recently approved PG&E’s 2023-2026 General Rate Case, which authorized 1,230 miles of undergrounding during those four years. PG&E is evaluating the GRC decision and creating the specific work plans for 2024 and beyond. Also, by mid-year, PG&E will file its 10-Year Undergrounding Plan, which was enabled by the passage of SB 884.

Here’s how the process works. Using sophisticated modeling, PG&E identifies the circuits with the highest wildfire risk. After engineering and permitting are completed, the most time- and labor-intensive part of the process — digging trenches and installing conduit, the piping that securely holds the electric lines in place—begins.

Once the civil construction work is complete, electric crews arrive to pull powerlines through the conduit, make the necessary electrical connections, de-energize the overhead lines and energize the underground lines. Final steps include removing the overhead lines and poles in some cases, and then completing paving and other work to return the surrounding area to a condition as good as or better than before the construction.

In recent months, on average, PG&E energized about 20 miles of undergrounded line each week. In all, customers on circuits in 20 counties now benefit from underground powerlines, extending from Trinity and Shasta counties in the north to Fresno County in the south.

Multiple benefits from undergrounding

Investing in undergrounding in the highest fire-risk areas benefits all PG&E customers in several ways — from improved air and water quality resulting from fewer fires; protection of wildlands; and over the long run, lower costs to customers due to reduced maintenance and vegetation management costs.

Expanding PG&E’s electric system underground in High Fire-Risk Areas (HFRAs) will not only help reduce wildfires caused by utility equipment, but also will improve reliability and reduce the need for safety-related power outages.

Go to www.pge.com/undergrounding to see PG&E’s progress and learn more about this crucial safety program.