North Carolina attack underscores vulnerability of power grid

An attack on power substations in North Carolina is putting a spotlight on the physical vulnerability of the electric grid in the United States. 

Law enforcement officials said that two power substations were damaged by gunfire on Sunday night in what they believe was an “intentional” attack on the power grid. The FBI has joined the investigation into the “the willful damage,” authorities said.

As of Tuesday afternoon, authorities had not named any suspects or detailed a motive. Utility company Duke Energy said Thursday that around 35,000 people remained without power, while electricity had been restored for about 10,000.

The company anticipates that “nearly all” customers would have their power back by Thursday. 

The incident prompted some experts to renew calls for change to protect the grid.  

“Ever since the [congressional Office of Technology Assessment] did a report on this topic back in 1990, experts have been telling the Congress that the grid is physically very vulnerable,” Granger Morgan, a professor at Carnegie Mellon University, said in an email.  

“We need a coordinated national strategy,” added Morgan, who chaired three recent studies on the U.S. power system by the U.S. National Academies.  

The U.S. power grid is largely decentralized and is made up of individual components such as power generators, transmission lines and substations that help to control voltage.  

Ross Baldick, professor emeritus of electrical and computer engineering at the University of Texas at Austin, said that it would be difficult to attack a generating station but that other parts of the grid are likely to be more vulnerable.  

“If we turn to transmission and distribution lines, the wires, and we turn to substations, they are very easy to attack,” said Baldick, whose research has included work on vulnerability of electric grids to terrorist attacks.  

“You can imagine an entity coordinating multiple, simultaneous attacks to cause widespread damage and if you damage enough stuff, most particularly devices called power transformers, generally there are only limited spares,” he added.  

Morgan said that implementing a coordinated national strategy will be difficult since it would involve getting various state and federal entities on the same page, some of which would be controlled by different constituencies. 

Yet he said it was also crucial to do so. 

“Congress and the administration need to work together to solve this messy problem before we have a major nationwide catastrophe,” Morgan said.  

In a follow-up call, he told The Hill that the issue is “partly a technical problem, but it’s mainly a political science problem with all the different parties with responsibilities.” 

“Other than put the right people in a room together and tell them ‘Look, you’ve got to figure out some politically feasible way to sort this out between federal and states rights and all those other issues,’ I don’t know what the answer is,” he said.  

Baldick said federal and state authorities could take steps to protect transmission lines and increase surveillance to deter potential threats. 

Generally, Baldick said, it’s difficult to defend substations since many of them are protected only by barbed wire.  

“Unless you move to putting it in a secure building that’s inaccessible, which may not be very easy to do, it’s pretty hard to defend against a determined adversary.”  

He added that transmission and distribution lines are “even less defensible” since they run through the countryside and could be accessed.  

“You could imagine someone just driving to a transmission line roughly where it crosses a road. They could walk in a ways to be away from a road and away from anybody looking at what they’re doing and they could mount some explosives,” he said.  

Asked about whether there should be more federal regulations, Baldick said the situation is complicated.  

“If it were free to institute a lot of hardening, then obviously the answer would be yes,” he said. “The hardening is not free. … You have to decide whether or not the expenditure … is going to be worth it in the context of a prospective terrorist attack.” 

In an increasingly digital world, the electric grid also faces cybersecurity threats.  

“A single cyberattack can shut down hundreds if not thousands of substations at once,” said Rajit Gadh, director of UCLA’s Smart Grid Energy Research Center.