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“Smart and Sturdy” Mark a Hurricane-Prepared Electric Grid

From Scott Carlberg

Smart and sturdy – two essential traits to harden an electric system against hurricanes. Utilities up and down the East Coast have been doing that for a long time now. Smart and sturdy can blunt the impact of a storm.

Smart: A grid system that can communicate – is networked – so it can isolate and self-report outages helps reduce restoration time. Lineworkers take less time searching for problems. They know where the fix is needed.

Sturdy: For example, utilities have been busy replacing wood poles with stronger wood or concrete poles, able to stand up against strong winds. Even stronger wires and poles can tolerate only so much. “The risk of airborne debris coming from outside of the right-of-way can exceed the risk from trees inside the right-of-way by a factor of as much as four to one,” said electric engineering trade group, IEEE. Sturdy also means protecting electric facilities from flooding, reinforcing lines and upgrading transmission tower materials.

Image: NOAA. Hurricane Florence

Hurricane season starts June 1. Electric systems in the Southeast and on the East Coast will get another test, it’s just not sure how tough the test may be. Investments have been made to improve the grid system.

  • What was SCE&G, “inspected and replaced thousands of poles in an eight-year period as part of efforts to rebuild and harden roughly one-third of its transmission system.” (Source)
  • After Wilma in 2005 it took FPL in Florida five days to restore all its substations. In 2017, one day. (Source)
  • In New Jersey, grid improvements installed before the March 2018 Nor’easters allowed the utility PSE&G to get a Princeton hospital back online in 29 minutes when other areas had outages more than 1,300 minutes. (Source)
  • Duke Energy’s South Carolina president told the Florence (SC) Rotary, “Proper design, tree trimming and proper maintenance of poles and wire… [Duke Energy is] constantly working to get better; to provide safer, more reliable and secure energy.” (Source)

Grid damage can come from many sources. “Flying debris such as roofs and road signs and vegetation such as falling trees and limbs are the primary causes of distribution-pole damage during a storm, not strong winds themselves,” said one electric infrastructure expert. Airborne debris coming from trees outside of the right-of-way can exceed the risk from trees inside the right-of-way by a factor of as much as four to one. (Source)

Investment in transmission according to the Energy Information Agency

Spending on infrastructure to deliver power has increased steadily as utilities build, upgrade, and replace station equipment, poles, fixtures, and overhead lines and devices.

Capital investment is the largest share of distribution costs to upgrade age equipment:

  • 70% of power transformers are 25 years of age or older,
  • 60% of circuit breakers are 30 years or older, and
  • 70% of transmission lines are 25 years or older. (Source)

The Energy Information Agency notes that over the past decade, investment in overhead poles, wires, devices, and fixtures such as sensors, relays, and circuits has risen by 69%, and spending on substation transformers and other station equipment has increased by 35%. Investment in customer meters has more than doubled over the past decade.

Operating a grid, from the largest network to the individual homeowner, takes planning, money and innovation even in the best times. Add severe storms and the challenge is compounded. Smart and sturdy help win against hurricanes.