Attack on North Carolina substation spotlights electric grid’s vulnerability — again

Around 40,000 electricity users in Moore County, N.C., were without power after a Saturday night attack on two power substations. Although few details were available, news reports said evidence at the scene “indicated that a firearm had been used to disable the equipment.”

The attack is similar to the 2013 gunfire attack on the Metcalf Transmission Substation in rural Santa Clara County, Calif., a crime that remains unsolved. But both incidents are a stark reminder of the fragility and vulnerability of our electric grid and how difficult it is to defend the grid against bad actors who want to damage our biggest and most important energy network.

In response to the attack, officials in Moore County have declared a state of emergency and a countywide curfew. Schools in the county were closed on Monday and Duke Energy officials have said that, based on the damage to the two substations, some county residents could be without power until Thursday. Local authorities and the FBI are investigating the crime.

The attack — and the difficulty that utilities such as Duke Energy face in repairing damaged substations — underscores an ongoing vulnerability in our electric sector: the lack of sufficient transformers and other equipment needed to repair or replace key components such as transformers. That vulnerability has been known for years. And it is being exposed yet again, at the same time that the domestic electric grid is becoming less reliable and electricity costs across the country are rising.

According to data published by the Department of Energy (DOE), in 2002, there were 23 “major disturbances and unusual occurrences” on the domestic electric grid. By 2021, the number jumped to more than 380. The same DOE reports show a huge increase in the number of events listed as “sabotage” or “cyberattack.”

Our grid is vulnerable to attacks by gunfire like the one in North Carolina because of its near-total reliance on large, one-of-a-kind, high-voltage transformers. These machines aren’t sexy but they are difficult to build and service. More than 90 percent of the electricity consumed in the U.S. passes through high-voltage transformers. If saboteurs were able to damage or disable a significant number of those transformers, they could cause widespread power outages. A 2014 analysis of the transformer vulnerability issue by the Electric Power Research Institute concluded that the “vulnerability is compounded by the fact that many U.S. high­-voltage transformers are approaching or exceeding their design lives.”

Security officials long have warned about the damage saboteurs can do with firearms, which are easily purchased and transported. The criminals who attacked the Metcalf facility used AK-47s and fired 120 rounds into the transformers at the substation. They stayed for less than an hour and left no matchable boot prints. Their shell casings had no fingerprints and their vehicles left no tire tracks. Outfitted with night-vision scopes and heavy wire cutters, they also cut fiber-optic cables and were able to briefly disable the local 911 emergency system and telephone lines.

John Sennett is a former FBI agent who went on to spend 16 years as the head of a utility security oversight office at the New York Public Service Commission until he retired from that position in 2019. He told me on Monday that “of all the physical and cyber threats against the electric power sector one of the most rudimentary, unsophisticated and obvious is the damage that can be done to power transformers inside substations from small arms fire. Many substations are in rural areas and most are only protected by a chain-link fence. The vulnerability from simple gunfire remains unaddressed at most substations around the country.”

Sennet believes policymakers have not paid enough attention to the need to protect substations and transformers, which increase or decrease the voltage on the grid. He said the vulnerability could be reduced by surrounding the transformers with ballistic barriers, a move he said “is not particularly costly or problematic.” Walls made of steel, composite materials, or masonry, “or a combination of them, can protect the transformers from bullets. … There is no good excuse for failing to do this. It is a low-tech solution to a low-tech but very real threat. And yet, too many power companies are reluctant to take this step because it is not nationally mandated. It is past time for ballistic barriers to be required — at least at all substations designated as critical.”  

Everyone should hope that, unlike the California case, the miscreants involved in the North Carolina attack are caught and prosecuted to the fullest extent of the law. But it’s already clear — and has been for a long time — that our electric grid is vulnerable to gunfire attacks. Nearly a decade after the attack on the Metcalf substation, the attack in Moore County provides yet another warning about our grid’s vulnerability. We need to put more focus on hardening our electric grid — and we need to get serious about it right now.

Robert Bryce is the host of the “Power Hungry Podcast,” executive producer of the documentary, “Juice: How Electricity Explains the World,” and the author of six books, including most recently, “A Question of Power: Electricity and the Wealth of Nations.” Follow him on Twitter and TikTok @pwrhungry.