Modern life in advanced industrial societies depends on the availability of certain basic utilities such as water, sewage service, and electric power. Probably the most vulnerable of these infrastructures is the electric grid, as the others are mostly underground, and the transmission towers, distribution poles, and substations are right out there in the open just asking for someone to come along and shoot them up. And that's exactly what happened on Saturday, Dec. 3, when two substations operated by Duke Energy in Moore County, North Carolina were sabotaged by unknown intruders.
These were no casual drive-by attacks by joyriding teenagers. The attackers knocked down a gate leading to one of the substations and used high-powered rifles to damage enough equipment so that 40,000 utility customers were without electricity. Fortunately, Duke Energy repaired or replaced the equipment fast enough so that things were basically back to normal in a few days, but for a while some water utilities were running on emergency power and a local hospital had to switch to its emergency generator.
On a larger scale, Russia has been targeting Ukraine's power grid with missiles, and has succeeded in knocking out the power to critical regions of that country, leading to mass evacuations before the coldest winter weather sets in. Of course, a war is not domestic terrorism, but the extreme vulnerability of power grids make them the target of choice when an enemy wants to get the most harm-inflicting bang for the bucks it spends on missiles and bombs.
What can be done to make the grid less vulnerable to terrorist attacks? It depends on which part of the grid you're examining.
Most current power grids consist of relatively few large central generating stations which feed power into the high-voltage transmission lines that cover dozens or hundreds of miles between the generators (generally in rural areas) and the places where most power is used (suburbs and cities). Where power is needed, substations transform and switch the high-voltage energy into lower-voltage distribution lines, which are the familiar one or three cables at the top of power poles, which connect to the transformers that step the voltage down further to 120 and 240 V for homes and somewhat higher voltages for businesses and industries.
The farther upstream you go in this distribution chain, the more damage you can do, but the harder it gets. Every now and then, a driver accidentally runs into a power pole and knocks it down. This results in an outage affecting perhaps a few dozen customers, and is fairly easily repaired in a day or less. Many localities are wired so that there is more than one pathway from the substation to any given customer, and so power can be restored quite rapidly to most users by isolating the problem and using alternate pathways until the damage is repaired.
On the other hand, an attack on one substation can put thousands of people in the dark, because substations are typically the only source of power for a given region. But as the Moore County incident showed, service can be restored in a few days, assuming enough spare parts are available. The most critical component is the substation transformer, because these cost hundreds of thousands of dollars and take a long time to manufacture and transport. You can't just order one on Amazon and get it in a couple of days.
Attacks on high-voltage transmission lines, while not unheard of, are (a) difficult and (b) dangerous, which is why they are so rare. And as with distribution lines, the utilities have designed multiple pathways for energy to get to most places, so the net harm from one transmission line going out is usually not that widespread, unless the grid is already stressed.
Finally, disabling an entire power plant can cause serious but not catastrophic outages. Again, most grids are resilient enough to take up the slack with other generating stations, and for terrorists to disable a power plant would be a grand-scale exploit comparable to the 9/11 attacks on the World Trade Center. The payoff in terms of domestic disruption would be much less, however, which is another reason you don't see a lot of terrorists going after power plants.
Nothing was mentioned in the news reports I saw as to whether any security-camera photos were obtained of the perpetrators of the Moore County attacks. Virtually all substations are probably now equipped with such cameras, but a systematic terrorist would note their locations in advance and make sure to shoot them to pieces before leaving. The knowledge that they'd be caught sooner or later will discourage some kinds of terrorists, but not others.
Finally, there's what you might call the fear factor. Working with limited budgets, terrorists want to produce the most anguish in the most people for a given effort. Having your power go out for a couple of days is inconvenient, surely, but it's not in the same league as having your head blown off by a bomb. There is some speculation that the Moore County attacks were connected with a local drag-queen show, but if all the terrorists wanted to do was to douse the lights at the drag-queen show, it would have been easier to cut off the power for a particular building than to wreck two substations. Terrorists are not always logical, however.
While the power grid is probably one of the more vulnerable types of infrastructure we have, it looks like the kinds of damage that can be done with a small-scale terrorist operation are relatively minor and short-term. And doing anything that would cause extensive long-term outages would take the operation out of the terrorist class into the civil-war class, because it would require multiple widely-separated and coordinated attacks, or else a concerted effort by what would amount to a whole militia.
I hope they catch the people who knocked out Moore County's power, not only for reasons of justice, but to find out why they chose that particular approach, and to see if we can get ahead of the next bunch who wants to damage the grid. In the meantime, terrorist attacks on power grids are not going to be high on my worry list, and they shouldn't be on yours either.
Sources: The online version of the Austin American-Statesman of Dec. 11 carried an editorial by Myron B. Pitts of the Fayetteville Observer entitled "After attacks, how safe are substations?" I also referred to the Wikipedia article "Moore County substation attack."
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