The Grid Optimization Blog

Terrorism: How Vulnerable is the Grid?

Terrorists easily shut down a number of Mexican substations with simple Molotov cocktails. The lasting damage is the precedent set, the object lesson to terrorists that shutting down the grid is pretty easy. It may even take a few more attacks before physical security of the grid finally gets the attention it deserves.


"Shortly after midnight, attackers armed with Molotov cocktails almost simultaneously disabled electrical substations in at least nine cities and towns in Michoacan, plunging an estimated 1 million people into darkness. The power was out for 15 hours." From the LA Times, Oct. 27


In the 1970s some of the San Francisco Bay Area antiwar protestors decided to knock out power to Berkeley. One group tried to pull down a tower with a winch and would have if the cops hadn't shown up. That incident created enough commotion for PG&E to take a very brief look at system vulnerability to physical attack.  Then the war ended, the hubbub died down and the issue went back to sleep.

Twenty years later, in the 1990s, I was on a secretive committee that was asked to pretend it was a saboteur and figure out the best way to shut down power on the west coast. It didn't take us long. We determined that two guys with hunting rifles, strategically placed, could shut down the entire Pacific Intertie with a few rounds and casually escape. The impact would be to destabilize and island areas throughout the western states, perhaps for weeks.

Well, our report was passed up to the top floor and we were told to keep everything hush-hush. Don't want to give the terrorists any ideas.

More recently system security has gotten a lot of attention again. But it has evolved almost totally into cyber security. A lot of money is being spent on very smart specialists meeting and eating in some of the finest establishments in the world and trying to figure out the best way to protect against digital dynamite tossed into the system by sophisticated hackers.

In the meantime a bunch of ordinary goons in southern Mexico figured out that they didn't need no stinkin' cyber-whatever. They just tossed burning bottles of gasoline over the substation fences. I don't know the details of the damage. But I can imagine transformer and breaker flashovers and fire damage that at least required some equipment replacement.

The biggest damage to our industry is the precedent set, the object lesson to terrorists that shutting down the grid is pretty easy. Hopefully the incident is also a wake-up call to focus more on the mundane physical protection of substations and other assets.

Whatever the lasting impacts, the cat is out of the bag and nobody's going to put it back in.

Discuss this Blog Entry 8

on Nov 3, 2013

It may well be that we need to start applying the same security standards around key substations and lines that we do for other high value potential terrorist targets. We already have sensors available to detect intrusion through the fence. And it's certainly possible to have movement detectors around the outside of substations. But what do you do if it's in an urban setting and people routinely come near the facility? Seems to me that one solution for urban facilities is to have larger footprints and set the equipment (breakers, xformers etc) further from the fence. But that doesn't stop someone shooting at the equipment.

Going further, we could have compact enclosed substations. Still, the line insulators on HVAC or HVDC are vulnerable.

I'm going to bet, however, that we won't change design standards until some major incidents occur in the US.

Mark in Utah (not verified)
on Nov 8, 2013

Back in the '70's a guy was dynamiting BPA towers in the Pacific Northwest, trying to extort money and black out the system. The lights stayed on, and they caught the guy.

It's not hard to black out a system, even for a prolong period of time. The larger EHV substation transformers are probably the most vulnerable part of the system, and because they are few in number are easy targets. It's very difficult to make them secure against outside gunshots. Millions would need to be spent for each transformer, not to mention the need to acquire additional land and the long construction period to accomplish it.

Security systems are for the most part worthless. You make them sensitive enough to detect someone walking around and you'll get numerous false alarms, which will render it unreliable and not trustworthy. After 50 false alarms who's going to respond to the 51st alarm in time to stop any damage? It'd only take minutes to do the damage. By the time someone responds the perpetraors will be long gone and enjoying a burger someplace.

on Nov 8, 2013

What you are saying then, in effect, is there is no feasible way to protect the grid should someone get serious about shutting it down. Particularly when it comes to long distance transmission. And I guess that's one reason the military is looking so closely at microgrids for base and other strategic facilities supply.

Phil (not verified)
on Nov 13, 2013

Food for thought, I believe there are many bennefits to micro grids and one big one will be for security in many ways! Just stop and think about putting most of your eggs in a few baskets or putting your eggs in several...

Utility man (not verified)
on Nov 11, 2013

I have worked with all of the utilities: electric, telephone, water and waste water and they are all very easily put out of service. I think the only way to stop terrorists is to stop the terrorist themselves. The effort should be made there. Hardening the utilities against attack may be pudent if it is severly lacking but if someone with knowledge wanted to destroy a plant they could do it no problem at any time. The more deverse the system the better it will stand up. Contol and monitoring is good to let you know what you have going on but automating it brings further troubles.

Anonymous (not verified)
on Nov 12, 2013

The security of the Grid is in its interconnectivity. If a line or a substation is taken out the power is re-routed. If a generator is taken out there are reserves. There is no way to defend against consolidated physical attacks in multiple areas other than to increase the connectivity.

External conductors will always be vunerable. Just this week a 2500MW of power was lost when a felt roof was blown off and landed on the line coming out of the Power Station. The lights stayed on!

That said, it is possible for one person with the right knowledge to disconnect the entire power system by telecommanding all the CB to open.

Robert Freeman (not verified)
on Nov 12, 2013

In my former life, prior to retirement, I was Power Supply Superintendent for a large electric utility.
I could have written the above article. I always stated that the
electric utility system and the pottable water system were two
of the must vulnerable systems we have to sabotage.

Relay Guru (not verified)
on Nov 22, 2013

I consult on system protection for various T&D and Nuclear utilities. They all seem to be spending crazy money on cyber protection and allowing the IT dept to dictate what is needed.
I'm certain I could do much more damage without a computer. sdg

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