No easy decisions to ensure a resilient power grid

The power is slowly coming back on for more than a million customers in Louisiana and Mississippi after Hurricane Ida destroyed the grid—though Tropical Storm Nicholas slowed some of that progress. The widespread loss of electrical service — so critical for health, safety and comfort — left people asking basic questions: How will I shop for food? Operate my medical devices? Educate my children and keep them safe?

Overhead power lines typically don’t warrant much thought from the general public — until the lines don’t work. Then people wonder whether their electricity service might be more secure if those lines were underground. More pointedly, they wonder why their utility provider hasn’t already moved them underground.

The issue is far more complicated, however. Initiatives aimed at making the electricity grid more resilient to weather and disasters must acknowledge two unpleasant realities. And everyone — customers, utilities, regulators, local, state and federal authorities — has a role to play in making the difficult decisions required to create a more resilient grid. 

The fact is, whatever steps are taken to harden the grid, there still are circumstances when the power will go out — especially during climate-driven disasters like wildfires and tropical storms. And the conversation must continue even after the lights come back on.

So, the hard 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 storm surges and flooding. So, selecting where to locate power lines means deciding which threat is the biggest concern.

Second, the people ultimately pay for any changes to 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.

It is true that undergrounding power lines can mitigate damage from wind and other weather events. But alternatives, such as a regular regimen of tree trimming and vegetation management strategies, replacing wood poles with steel, concrete or fiberglass composite ones or reinforcing utility poles with guy wires, may be nearly as effective in mitigating storm damage and may cost less. And undergrounding power lines may make repairs more complicated.

Securing the transmission system is more difficult because there are fewer technical options. Burying transmission lines is technically feasible and may be practical over short distances. But all power lines lose some of the electricity they carry as heat — and if this heat builds up, it ultimately restricts the line’s ability to carry power over longer distances. Air effectively dissipates heat from above-ground lines, but buried lines are more vulnerable to heating.

Relocating transmission lines or building extra lines as backups may be options for strengthening the system in many places — options that come with their own challenges.

The bipartisan Infrastructure Investment and Jobs Act includes a proposal that would address some of the challenges of transmission line siting, but concerns regarding safety and cost allocation would remain. Even though the science is inconclusive, many people are concerned about possible health risks from exposure to electromagnetic fields that emanate from high-voltage lines. That issue is just one of several that leaves regulatory agencies struggling to site transmission lines and allocate the costs.

The variety of strategies available means that differences in geography, population density, societal preferences and willingness to pay across a utility’s service area ensures that no blanket policy will work everywhere. To achieve the best solution for any area, a collaborative approach is crucial and the District of Columbia provides a good example of how this can work.

After identifying a need for a more resilient grid in 2012, then Mayor Vincent Gray established the Mayor’s Power Line Undergrounding Task Force. This broad collection of stakeholders analyzed the costs and benefits of different proposals for securing the infrastructure and recommended options for improving the District’s power line system. The utility began submitting plans to the D.C. Public Service Commission in 2017.

Whatever steps utilities take to harden the grid, there still are circumstances when the power will go out — especially during climate-driven disasters like wildfires and tropical storms. The goal is to make those outages short and contained. We can do that by working together to build power systems that are customized for local needs and budgets yet are better able to withstand the next big storm.

Theodore J. Kury is the director of energy studies at the Public Utility Research Center at the University of Florida.