by Rebecca Walker — October 20, 2010—A new study from Paul Hines of the University of Vermont and Seth Blumsack of Penn State counters recent arguments that terrorists could bring down the U.S. electric grid by striking small unimportant parts of it.
Studies earlier this year in Safety Scienceand Nature used a mathematical model called a topological model to show that an attack on one area could cascade through the system like dominoes. But Hines says it couldn’t happen that way.
“Some modelers have gotten so fascinated with these abstract networks that they’ve ignored the physics of how things actually work like electricity infrastructure,” he said.
For example, the Safety Science paper came to the “highly counter-intuitive conclusion,” Hines says, that the smallest, lowest-flow parts of the electrical system, for example a minor substation in a neighborhood, were likely to be the most effective spots for a targeted attack to bring down the U.S. grid.
Hines and Blumsack’s recent study, published in the journal Chaos on Sept. 28, found just the opposite. Drawing on real-world data from the Eastern U.S. power grid and accounting for the two most important laws of physics governing the flow of electricity, they show that “the most vulnerable locations are the ones that have most flow through them,” Hines said.
“If the government takes these topological models seriously,” Hines said, “and changes their investment strategy to put walls around the substations that have the least amount of flow it would be a massive waste of resources.”
“The way topological cascades typically occur is they’re more like real dominoes,” says Hines, an assistant professor in UVM’s College of Engineering and Mathematical Sciences. “When you push a domino the only thing that can fall is the one next to it. Whereas in a power grid you might push one domino and the next one to fall might be a hundred miles away.”
That’s because, “when a transmission line fails instantly, at nearly the speed of light, everything changes. Everything that is connected will change just a little bit,” Hines said, “But in ways that are hard to predict.” This strangeness is compounded by the fact that the U.S. electric grid is more an intractable patchwork of history than a rational design.
For more information, see the University of Vermont Web site.
