January 10, 2017
Dr. Mack Grady
Professor, Electrical & Computer Engineering
Academic Specialization: Electric Power and Renewable Energy
Hollywood's long fascination with disasters both real and imagined has given us near-countless science fiction dramas set in a harsh, post-apocalyptic world. Deprived of even the most basic modern conveniences, society quickly devolves into a brutal tribal struggle. Entertaining as these dystopian fantasies may be, they may not be so farfetched. But that is a scenario one Baylor researcher is working hard to make a lot less likely.
Dr. Mack Grady is a soft-spoken Baylor electrical engineering professor who grew up in the small town of Oglesby, just a thirty-minute drive from his laboratory in the Baylor Research and Innovation Collaborative. After receiving his undergraduate degree from UT Arlington, he earned his master's and Ph.D. degrees from Purdue, though the two graduate degrees were separated by a seven-year stint in the energy industry as a power-grid planning engineer.
Grady spent nearly 30 years teaching at the University of Texas in Austin before retiring to Baylor in 2012, where he continued to teach, conduct research and consult with the power industry. One day in 2008 a defense contractor working for DTRA—the Defense Threat Reduction Agency, a subunit of the Department of Defense—contacted him. He was caught a bit off-guard.
"It was a total surprise; I didn't know anybody!" he recalled. "They knew about my power quality background so they had me do a little work for them. Then, the more I worked the more I learned and I've been working with them ever since."
Though DTRA studies all kinds of threats to national security, the agency called on Grady to help develop computer simulations of how a nuclear electromagnetic pulse weapon would affect the nation's power generation and distribution system if exploded high above the U.S. These high-altitude nuclear devices—called HEMPS—do their destructive work not by explosive force, but through an intense electromagnetic pulse they are specifically designed to emit. Setting off these weapons generates three types of damaging electromagnetic energy, deemed E1, E2 and E3.
The first two types dissipate fairly quickly, and so only constitute a serious threat if exploded near the Earth's surface, close to a large city, for example. In that case, a nuclear EMP device would produce powerful E1 effects for a tiny fraction of a second. But that brief pulse would send an immense surge of electromagnetic energy through the atmosphere, wiping out millions of electronic devices for miles around. E2 effects last a bit longer than the E1 pulse, and resemble lightning. Because most electrical systems are already well protected against lightning damage, the E2 effect is considered least worrisome.
However, the E3 pulse produced by a weapon detonated 100 to 250 miles above the Earth creates a very large current lasting as long as several minutes. The pulse interacts with and distorts the Earth's magnetic field, causing minutes-long surges of abnormal, direct current to flow through transmission lines than are often 50 to 100 miles long. Though these transmission lines routinely carry alternating current of that magnitude and higher, the E3 pulses produce direct current electricity. When those dc pulses flow down the lines to massive transformers and other equipment designed to handle ac current only, they quickly become what the industry calls "saturated." The result is a sudden and dramatic increase in internal losses and heat, causing the equipment to fail in a matter of minutes, shutting down the power transmission grid we all rely on. That's why Grady was the right guy to call.
"What I know best is the grid," he said. "We're trying to simulate what we know about E3 events and the characteristics of the currents they would produce. I'll take that information and try to determine the impact, to figure out what would it do to the grid. Then given that, how do we combat it, how do we minimize it?" Grady is quick to point out that he and other EMP researchers are hampered by one troublesome fact: "We've got to simulate something that we can never test!"
Fortunately—or unfortunately, depending on your perspective—there is a purely natural phenomenon that offers Grady a reasonably good simulation of a HEMP's E3 pulse. It's called a GMD, for geomagnetic disturbance. GMDs are created when the Earth is struck by the immense outpouring of high-energy plasma produced by a kind of solar storm or flare called a "coronal mass ejection," or CME.
An infamous solar flare in 1859 has become known as the "Carrington Event," after the English astronomer Richard C. Carrington who with colleague Richard Hogson observed and recorded the storm's departure from the sun and its subsequent impact with Earth. It is a kind of standard against which CMEs are ranked. Apparently the sun launched that CME on a direct trajectory toward the Earth, which bore the full brunt of its power. The resulting GMD was so intense it interrupted or burned out the few rudimentary electrical devices of the day, including telegraphy systems worldwide. Fires broke out, and some telegraph operators suffered electrical shocks. The effect of a severe solar-induced GMD on today's electrical- and electronics-dependent world would be far more devastating.
Intense CMEs with the potential to cripple the grid occur every few years, but we've been lucky. In 2001 the sun spewed the strongest solar flare ever recorded into space at a whopping 4.5 million miles per hour. Had that storm headed in Earth's direction it would have arrived in just 20 hours. The closest thing to a Carrington-class event to occur recently was in 2012, when an powerful CME disrupted communications and grids, and played havoc with satellites. But that storm merely grazed the Earth. Had it occurred a week earlier, we'd have been right in its path.
A direct hit by either a strong solar storm or a HEMP could wipe out power generation plants and electrical grids, which in turn would take down radio and television stations, ATMs, computer networks, cell phones and landlines—virtually anything electrical or electronic. Not even gasoline pumps would work. What's worse, entire states would be immediately affected. Overseas markets would soon grind to a halt as electronic trading and banking ceased. It could take several weeks to a month to even partially get things up and going again. That's a notion that makes those Hollywood disaster scenarios seem a lot less fictitious.
"These transformers, to buy them takes a year. Most are not made in the Unites States: Germany builds some, China builds some. We need to be thinking long-term about building more here as we did in the past," Grady said. "It's a little scary!"
The simulations that Grady and his graduate students are developing will help planners design new protections. But there are already some in place. "They're just big circuit breakers, basically, but they're all set up to deal with the kinds of events we already handle very well, like lightning," he explains. "Well, we've got a new lightning and a lot of things have to change. If you can make (recovery) a week-long event instead of a months-long event, then you've done a lot."
Grady is no "prepper," but he thinks people should consider what weeks or months without electricity would be like, and take some basic measures. And he is one very
"It's a good time to buy a generator, and you probably need to have something of value to trade," he advised. "Maybe Jack Daniels?"
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