Grid securityCan Burying Power Lines Protect Storm-Wracked Electric Grids? Not Always
Electricity is critical for health, safety and comfort. People wonder whether their electricity service might be more secure if those lines were buried underground. But I’ve studied this question for utilities and regulators, and the answer is not straightforward. There are many ways to make power grids more resilient, but they are all costly, require the involvement of many agencies, businesses and power customers, and may not solve the problem.
The good news when Hurricane Ida churned into Louisiana on Aug. 29, 2021 was that levees held up – especially those that were strengthened after Hurricane Katrina flooded New Orleans in 2005. The bad news: In many places, power systems failed. Nearly five days later, more than 80% of New Orleans customers were still in the dark, in sweltering heat.
Electricity is critical for health, safety and comfort. Without it, it’s hard to buy groceries, fuel your car or get cash from an ATM. Many medical devices, including power wheelchairs, ventilators and nebulizers, run on electricity. Schools can’t operate without power, and kids can’t attend class online without computers or electricity.
Dramatic images of damaged power lines can make people wonder whether their electricity service might be more secure if those lines were buried underground. But I’ve studied this question for utilities and regulators, and the answer is not straightforward. There are many ways to make power grids more resilient, but they are all costly, require the involvement of many agencies, businesses and power customers, and may not solve the problem.
It’s Impossible to Completely Protect the Grid
Ideas for making the electricity grid more resilient to weather and disasters have to acknowledge two unpleasant realities. First, there is no way to completely protect the grid.
Above-ground lines are vulnerable to damaging winds, flying debris and falling trees. But underground lines are susceptible to damage from water incursion driven by storm surges or flooding. So, choosing the location of power lines means choosing which threat is more manageable.
Second, the public ultimately pays for maintaining the power grid, either via their electric bills or through taxes. The greatest responsibility facing utilities, their regulators and government agencies is ensuring that people receive benefits commensurate with the money they pay for their electricity service.
Deciding how to make the grid more resilient begins locally. In general, the best place to locate power lines depends on what type of damage is most likely in that area. If a region is more concerned with storm surge and flooding, the best choice may be locating power lines above ground, with regular tree trimming to keep branches from falling on power lines. Power poles made from resilient materials, such as fiberglass composites and concrete, can withstand damaging winds and flying debris better than traditional wooden poles.
