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As more than a million residents from Houston to Galveston Island sweat through their fifth day without electricity following Hurricane Beryl’s brief but tumultuous visit, conversations swirl online about how CenterPoint Energy, the region's largest electricity provider, can prevent widespread and long-term power outages going forward.
The No. 1 idea bandied about: bury the power lines.
The rationale is that putting electric lines underground would shield them from high winds, falling tree limbs and other wire-snapping incidents, such as automobile crashes that take out power poles. The idea, commenters asserted, would have avoided the mass outages resulting from Beryl and the derecho in May.
Burying power lines, also known as “undergrounding,” already is used in the popular planned communities of The Woodlands and Bridgeland, both located more than 30 miles outside the city’s center.
About 60 percent of CenterPoint’s system, including both transmission and distribution lines, already are underground, according to Michelle Hundley, CenterPoint’s manager of external communications.
Underground distribution lines, she added, are mostly located in areas where residential developers have paid for them.
While research suggests there are benefits to burying power lines, subject matter experts and CenterPoint representatives say the solution to the region’s electricity distribution problems may not be so simple.
The case for buried lines
The Texas power grid consists of three sectors, said Bruce Race, director for the University of Houston's Center of Sustainability and Resilience: generation, transmission and distribution.
While certain major weather events, like last summer’s extreme heat and 2021’s Winter Storm Uri, created problems in the generation sector, the summer of 2024 will be remembered for distribution failures, Race said.
Our regional distribution system – how CenterPoint moves electricity from the grid to ratepayers – is not that resilient, Race said.
“Part of the local and regional solution might be strategic investment in undergrounding,” Race said.
According to CenterPoint’s proposed resiliency plan, which outlines planned investments in strengthening the region’s electric grid, strategically undergrounding the company’s distribution wires would help protect them from tornadoes and other high-wind events, hurricanes, extreme temperature events, wildfires, physical attacks or third-party damage.
The plan also calls for $31.2 million in capital investments to bury certain power lines, the second-least expensive of eight proposed system hardening measures.
In southwest Florida, another region susceptible to major weather events, Florida Power and Light is encouraging its customers to make the switch from overhead to underground wiring.
According to WGCU, southwest Florida’s PBS and NPR affiliate, the electric provider found underground lines had six times fewer outages than overhead lines during severe weather and performed 50 percent better day to day.
Despite the advantages, undergrounding presents its own set of drawbacks, said Daniel Cohan, Rice University professor of civil and electrical engineering, Race and CenterPoint.
Why not bury the lines?
In a nutshell, cost.
Burying distribution power lines en masse would cost three to five times more than putting lines overhead, Race said. That cost, he added, ultimately would fall to electricity customers.
Of the eight proposed grid-strengthening measures CenterPoint presents in its resiliency plan, undergrounding was considered as an alternative for three of them. Each of those three times, however, it was dismissed as cost prohibitive.
Additionally, Cohan said, underground line repairs often are more expensive and time consuming than overhead line fixes.
He also cautioned that the large-scale burial of power lines is unlikely to prevent widespread outages.
Burying power lines in every Houston neighborhood, Hundley’s email said, may not be possible.
“Because many neighborhoods in Houston are over 100 years old, the streets and yards are not designed to support underground distribution lines,” she wrote.
While burying power lines across the board may not be feasible, experts say it could be part of a larger grid-strengthening solution.
Strategic burying
Grid resilience, Race said, must be discussed in a holistic way.
He suggested that burying lines in strategically identified areas could work in tandem with other steps toward increasing resiliency.
Cohan agreed.
“There may be specific instances where it makes sense to bury a power line,” Cohan said. “But with tens of thousands of miles of distribution lines criss-crossing our region, it's not likely that we're going to have a full-scale burying of power lines that's going to be anywhere near as cost effective as other steps that might be taken.”
Other steps toward increasing grid resiliency, Race said, could include incorporating more backup power sources and better communication systems when preparing for major weather events. Trimming and better maintaining trees and greenery near power lines also could help.
A July 2022 Harris County-focused study by researchers from Princeton University and Huazhong University of Science and Technology in China found that strategically burying power lines could significantly reduce hurricane-related power outage risks.
The researchers found that strategically burying power lines – specifically the 5 percent of wires closest to the root nodes of distribution networks – would make it 15 times less likely for residents to experience a prolonged power outage than if an electricity provider were to randomly bury lines.
CenterPoint’s resiliency plan suggests the company intends to invest in strategic burying, with a line item included to fund the undergrounding of power lines near freeway crossings and other targeted locations.
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