Burying power lines for wildfire prevention is effective but

As deadly wildfires have destroyed communities from California to Maui, the nation’s largest utility, Pacific Gas and Electric, is making headway on its ambitious goal to move 10,000 miles of power lines in fire-prone areas underground, which would greatly reduce ignition risk.

“We’re coming off of a historic drought and those conditions are materially different than the conditions that we saw just 10 short years ago. And so now is absolutely the right time to be taking bold, decisive action with regard to the grid safety,” said Jamie Martin, PG&E’s vice president of undergrounding.

Five years ago, PG&E’s equipment sparked the deadly Camp Fire, which destroyed the town of Paradise, California, and killed 85 people. The massive liabilities drove the utility into bankruptcy, from which it emerged in 2020. But just a year later, in the same county, PG&E’s equipment started another catastrophic fire, prompting the utility to announce its extensive undergrounding plan. The utility has undergrounded 350 miles of power lines so far this year, and more than 600 miles since 2021.

While Martin says moving power lines underground reduces ignition risk by 98%, it comes at a steep cost. Data compiled by the California Public Utilities Commission shows that undergrounding just one mile costs anywhere between $1.85 million and $6.1 million, meaning PG&E’s total plan would likely be in the tens of billions. The bill would be footed by PG&E’s customers, who already face some of the highest rates in the nation.

“If we keep pushing up electricity rates, the most vulnerable of us are not going to be able to pay,” says Katy Morsony, a staff attorney with The Utility Reform Network, a consumer advocacy group that supports a more limited approach to undergrounding.

Since PG&E earns a guaranteed rate of return on capital investments, the utility is inherently incentivized to undertake more expensive infrastructure projects such as undergrounding, explained Morsony and Daniel Kirschen, a professor of power and energy systems at the University of Washington. This is how the utility makes money, not by selling electricity or gas.

“Undergrounding […] costs a lot of money. It’s a large investment. So that would increase the revenue that the utilities collect,” Kirschen explains. “Now, the question is would these other solutions be as effective as those big investment projects? That’s where the regulators have to step in.”

PG&E said in a statement that, “In the case of undergrounding, our investors’ priorities are aligned with those of our customers and our safety regulators.”

Although it’s expensive, burying power lines isn’t new. It’s common practice in city centers, where overhead lines would be obstructive, and more common in Europe overall, where cities are denser. Only about 18% of distribution lines in the U.S. are underground, though for both safety and aesthetic reasons, today almost all new lines that are built are…