California 'undergrounding' approach leaves lower-income populations disadvantaged

Lower-income communities in California shoulder a disproportionate share of fire-prone overhead power lines and wooden utility poles, a new study has found.

While one of the most effective ways to prevent wildfires and improve system resilience is to bury power lines underground, doing so largely occurs at the expense of the local community, the study authors noted.

Because decisions about such burial are often based on whether the local population can afford the project costs — up to $5 million per mile — most “undergrounding” has occurred in wealthy areas, according to the study, published Monday in Nature Energy.

“Distribution grids in low-income communities are in a wildfire safety deficit,” lead study author Zhecheng Wang, a postdoctoral scholar in electrical engineering, said in a statement.

California’s Public Utilities Commission allows communities, developers and property owners to identify areas for undergrounding, as well as receive funding for a small portion of the cost from their utility.

Nonetheless, wildfire threat and income level have not factored into the regulator’s criteria for which projects should advance and who should pay for them, the researchers explained.

If California continues with this approach, the per-household cost of burying existing fire-prone overhead lines will soon become significantly higher in lower-income census blocks, according to the study.

For blocks in areas where wildfires are most likely to impact power lines, the authors estimated that the cost would be $37,000 per household at the $200,000 income level, and more than three times that at the $50,000 income level.

To identify which places might be most vulnerable, the scientists created a first-of-its-kind map depicting wildfire risk of power lines across California.

Using an AI-powered model, they identified overhead lines in Google Street View images and filled in gaps in areas where photos weren’t available.

The researchers then overlaid their results with maps of tree canopies and census data, which included household income and education levels.

Aboveground power lines exacerbate not just the threat of wildfire itself, but they also can jeopardize energy security by trigging preemptive power shut-offs amid severe weather conditions, the authors noted.

These shutdowns have a great impact in low-income neighborhoods, where residents are less likely to install solar panels or generators that could keep them powered through an outage, according to the study.

“Our current electric infrastructure leaves low-income communities doubly vulnerable,” corresponding author Ram Rajagopal, an associate professor of civil and environmental engineering at Stanford University, said in a statement.

“They’re more likely to have power lines at risk during wildfires, and they’re less likely to have backup power,” Rajagopal added.

Aiming to offer a sustainable policy solution to this imbalance, the researchers worked on a scheme that would allocate the costs of undergrounding based on a neighborhood’s median income.

They suggested that the California Public Utilities Commission give communities with lower income levels the opportunity to split the cost of burying power lines among all utility customers.

In areas above a certain income threshold, communities would be able to choose between paying for burying power lines locally or implementing other fire prevention methods — such as replacing poles or trimming trees on a routine basis, per the study.

“Justification for utility-wide cost allocation goes beyond equity and affordability,” the authors wrote. “Improved grid resilience to wildfires in low-income communities and high-fire-threat areas can benefit all communities”

Without such changes, wildfire-induced outages could impact other areas downstream or harm adjacent ecosystems and air quality, according to the authors.

And because utilities are held liable for blazes caused by their infrastructure, all California utility customers end up shouldering the burden, the scientists added. 

“We need to reshape policies to explicitly take the wildfire risk and income levels as eligibility criteria to socialize the cost,” Wang said.