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Wading through industry fear mongering and the new Godzilla movie: just what the heck are the facts on EMPs and the grid?

EMPs are flippin’ everywhere these days.

Seriously. From fire-and-brimstone articles on the number of Americans who could die from a pulse attack to popular films currently in the theater, you just can’t escape those electromagnetic pulses, it seems.

Three hours after I spoke with Mark McGranaghan at the Electric Power Research Institute (EPRI) about the science behind all those angry EMP headlines, I went to see the new “Godzilla,” not realizing that Godzilla would only do a cameo in his own movie and that most of the flick is about giant, apparently very peeved bugs with one superpower: They can EMP themselves from the inside and knock your electronics silly.

It was an interesting coincidence. And, although I didn’t know to ask Mark at the time, I’d say that those bugs’ power wouldn’t actually be labeled EMP by McGranaghan and company. Instead, dear filmmakers, that’s an IEMI—an intentional electromagnetic interference. 

Granted, the intentions are from bugs rather than a terrorist cell or, say, the gang from the first remake of “Ocean’s 11,” but I think I grasped the conversation enough to make that call. Those bugs aren’t EMPing. They’re IEMIing—to coin a phrase.

So, what is EMP then? Think bigger and badder than any big, bad giant bug can produce. Think not just impacting a city but impacting, say, half the country.

According to McGranaghan, vice president of power delivery & utilization at EPRI, most of those “the sky is falling” articles discussing EMPs are picturing a scenario where a bomb is detonated in the atmosphere that would impact a wide area. That would create two major issues: a transient event (that is similar to lightning, but with lower energy) and a longer electromagnetic signal similar to a solar flare.

That transient event impacts everyone, not just the power industry. It would run on a very fast “wavefront” and take out circuit boards and electronic equipment from Disneyland to your local substation. Electronics are your weak link here, and that’s not restricted—no matter what some articles may tell you—to the power system.

Here’s the good news, straight from McGranaghan: “Transient voltages from EMPs are not big enough to impact transmission equipment.”

What that means is, while, yes, control systems and electronics connected to the system are vulnerable—as is everything from your iPhone to the giant electronic billboard in Times Square—we, as an industry, are not more vulnerable than others when it comes to EMPs. 

The second part of the event—that long electromagnetic signal—would be unique to impacting the power system because it can saturate transformers and the like in a manner quite similar to solar flares. (For our discussion with EPRI on the impact of solar flares on the grid, click this link.)

But, even in the case of solar flares, there has been little hard evidence on those signals having a huge impact. (They are still studying these events.)

With the lack of serious evidence on the long-term impact of the electromagnetic signal and the ability of most electronics to recover from a pulse—at least a localized one—in a fairly short period, why would someone—anyone—utilize an EMP attack over a traditional explosion? (In other words, why detonate a bomb in the atmosphere creating an EMP and not just blow things up on ground level?)

The argument—despite recent screaming headlines to the contrary—is that an EMP event wouldn’t kill people and wouldn’t massively destroy infrastructure. There’s little likelihood people would die from the blast, and radiation impacts are minimal.

Where we all get a little crazy is in the speculation of what would happen when we lose our electronics. Will we pull together and weather it or freak out and riot? Will it all depend on how long the power is out? It’s the human factor that’s at question here—not grid equipment.

“Those worst-case scenarios are all just speculation as to how society would react,” McGranaghan said. “Those scenarios would involve the grid not coming back up for a long time, which would not necessarily be the case. The basic elements of the grid would not be impacted, just the control equipment.”

So, in the great fear of EMP attacks, it’s not really the grid you need to worry about. It’s “normal human reaction”—to quote Peter O’Toole’s character in the classic “How to Steal a Million.”

Preventing an EMP attack from a foreign power or a terrorist cell should certainly be a national imperative. But, singling out the power industry as particularly impacted over transportation, communications or other notable bits of infrastructure is erroneous. With a big EMP attack, every industry is in this together, really.

Now, if we go down the scale to the IEMI—localized attacks like the Godzilla bugs or the Ocean’s 11 gang—and look at that: McGranaghan notes that a single substation hit by an IEMI could be “reconfigured in just a matter of days” with the modular options at work in today’s system.

“We had tornadoes in the Southeast recently that took out whole substations. We still reconfigured those in a matter of weeks,” he added.

But, in case you’re wondering, utilities are studying the impacts of IEMI and EMP attacks and how to mitigate issues, as they also study other high risk scenarios such as cyber hackers, massive storms, major floods and even direct physical attacks.

The question is: Where do you put EMPs on the scale? Preparing for all of those issues takes money, and a utility has to weigh impact vs. risk.

“When you talk about looking at design considerations for events very unlikely like this, you look at what assets are the most critical where you could change the design based on that risk,” he said.

So, where does a utility start if they are concerned about IEMI and EMPs?

Just to be clear here, McGranaghan noted that a physical attack, such as the one in the Metcalf substation that got such press earlier this year, would likely be more dangerous than a targeted IEMI.

But, there are preparations going on, and he does have a list of things for you to consider which are similar to how you’d deal with a physical security issue (and may help in both areas): 

  • An honest look at assets across the board assessing exposure and impacts.
  • A critical ranking of those assets.
  • A studied plan to upgrade asset hardening.
  • An investment in control center shielding (at regional control centers, perhaps, rather than localized ones).
  • A look at smaller investments, like new fencing that could block the lines of sight for physical attacks as well have attenuation for EMP/IEMI or monitoring equipment that can detect intrusions.


As McGranaghan pointed out in our chat, it’s still unrealistic to invest in the military-level specifications required to make a control center immune to EMP. It would be very difficult (and very expensive) to meet those standards for a risk event not particularly high on the event level equation.

But, don’t you think that means EMPs and IEMIs are totally off the utility radar, because they aren’t. There are workshops and confidential meetings to share information, along with coordination and test protocols. Assessment is on-going, too, and no utility has to face these issues “in a vacuum,” as McGranaghan noted. There are people out there to talk to.

Beyond peers, though, the other group you really need to talk to about all of this is your customers, though we know that’s a sensitive topic. But, consumers need to know that utilities are examining these things, are thinking about them. No one is turning a blind eye to this sensitive issue, despite what some reporters may be writing.

“We are all concerned, and we are continually evaluating the resiliency of the infrastructure. EMP is another consideration that is in the risk mix. This is not something utilities are ignoring,” he added.

But, for now, EMPs remain the stuff of pop culture and active imaginations. And while we all want to make sure we can bounce back from nightmare scenarios (without having to call on mythical help like Godzilla), first we have to figure out which nightmares could become reality and which are most likely to remain trapped in celluloid and sleeping brain cells.

Kathleen Wolf Davis's picture

Thank Kathleen for the Post!

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