Hurricane power outages: Why is the grid so vulnerable?

Oct 7, 2016

Hurricane Matthew has brought high winds and flooding to Florida, two big menaces to the power grid.

More than a million Floridians were in the dark today, according to the state public service commission, with more than a million state residents still in the storm’s path.

It’s not that Florida and its utility companies haven’t prepared. They invested $2 billion the last decade to toughen the grid with things like concrete power poles to replace wood poles. But no system is completely stormproof.

One issue: The grid in Florida and nationwide has so many poles and wires to start out with. It’s a long-distance system that evolved over time. A century ago, power systems were built locally.

“The generators were very close to the customers,” Larry Reilly said, a former utility CEO now with Rosewood Energy Consulting. “But over time, with advances in transmission technology and economies of scale, the grid tended to centralize and generators tended to be moved away from the population centers.”

In a hurricane, long-distance transmission wires are vulnerable to falling trees and flying debris.

“If a transmission line is taken out of service, it can take out tens of thousands of customers at the same time,” Reilly said.

Another issue is ground-level electric substations that in Florida are very close to sea level. Some flood regularly during major storms, but that’s how the system was built.

“You put the equipment where people have decided to live,” said Mike Jacobs, senior energy analyst at the Union of Concerned Scientists, which estimates the number of flood-endangered substations in Southeastern Florida will triple to 119 by 2070. “The settlements came before the electricity. And coastal areas certainly in Florida don’t have a lot of high ground to choose from.”

The grid problem is getting worse. In the last three decades, major outages in America have multiplied twentyfold, according to engineering professor Massoud Amin at the University of Minnesota.  

“There are two factors,” Amin said. “Unprecedented weather hitting them. And secondly, it’s aging infrastructure, because the average age in the overall system is somewhere between 40 to 60 years old.”

An analyst once told me that today’s grid is like inheriting your great-grandfather’s car. So a disaster like Hurricane Matthew could be an opportunity to grid reformers like Amin — not just to rebuild, but to build back better and more resilient.