No easy decisions to ensure a resilient power grid
Power is slowly returning for more than a million customers in Louisiana and Mississippi after Hurricane Ida destroyed the grid, although Tropical Storm Nicholas slowed some of that progress. The widespread loss of electrical service – so critical to health, safety and comfort – has left people asking basic questions: How am I going to buy food? Operate my medical devices? Educate my children and keep them safe?
Overhead power lines generally don’t deserve much thought on the part of the general public – until the lines don’t work. Then people wonder if their electricity service wouldn’t be safer if these lines were underground. Specifically, they wonder why their utility provider hasn’t already moved them underground.
The question is, however, much more complicated. Initiatives to make the electricity grid more weather and disaster resistant must recognize two unpleasant realities. And everyone – customers, utilities, regulators, local, state and federal authorities – has a role to play in making the tough decisions needed to build a more resilient network.
The point is, no matter what steps are taken to harden the grid, there are always circumstances where the power will be cut off, especially during climate-related disasters like forest fires and tropical storms. And the conversation must continue even after the lights come back on.
So, the harsh realities. First, there is no way to completely protect the network. Overhead lines are vulnerable to damaging winds, flying debris and falling trees. But underground lines are susceptible to damage from storm surges and flooding. So, choosing where to locate power lines means deciding which threat is of greatest concern.
Second, people ultimately pay for any changes to the electricity grid, either through their electricity bills or through taxes. The biggest responsibility of utilities, their regulators, and government agencies is to ensure that people receive benefits commensurate with the money they pay for their electric service.
It is true that burying power lines can mitigate damage from wind and other weather events. But alternatives, such as a regular regimen of tree pruning and vegetation management strategies, replacing wood poles with steel, concrete, or fiberglass poles, or strengthening utility poles with guy wires, can be almost as effective in mitigating storm damage and may cost less. And burying power lines can make repairs more complicated.
Securing the transmission system is more difficult because there are fewer technical options. Burying transmission lines is technically feasible and can be practical over short distances. But all power lines lose some of the electricity they carry in the form of heat – and if that heat builds up, it ultimately limits the line’s ability to carry electricity over longer distances. Air efficiently dissipates heat from overhead lines, but buried lines are more vulnerable to heating.
Relocating transmission lines or building additional lines as backups can be options for hardening the system in many places – options that present their own challenges.
The bipartisan Infrastructure Investment and Jobs Act includes a proposal that would address some of the challenges of locating transmission lines, but concerns about safety and cost sharing would remain. Even though the science is inconclusive, many people are concerned about the potential health risks associated with exposure to electromagnetic fields from power lines. This issue is just one of many issues that prevent regulators from locating transmission lines and spreading costs.
The variety of strategies available means that differences in geography, population density, societal preferences and willingness to pay in a utility’s service area ensure that no comprehensive 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 the need for a more resilient network in 2012, Mayor Vincent Gray created the Mayor’s Task Force on Burying Power Lines. This wide range of stakeholders analyzed the costs and benefits of different proposals for securing the infrastructure and recommended options to improve the district power line system. The public service began submitting plans to the DC Civil Service Commission in 2017.
No matter what steps utilities take to harden the grid, there are always circumstances where the power will be cut off, especially during climate-related disasters like forest fires and tropical storms. The goal is to make these failures short and contained. We can do this by working together to build power systems to suit local needs and budgets while being better able to weather the next big storm.
Theodore J. Kury is Director of Energy Studies at the Public Utility Research Center at the University of Florida.