UNIVERSITY PARK, Pa. - A recent study of the U.S. power grid finds that a major disruption could result from the loss of only 2 percent of its electrical substations.

The study, conducted by researchers at Penn State University and the Department of Energy's (DOE's) National Renewable Energy Laboratory, involved mathematically modeling the electrical grid with more than 14,000 "nodes" at which either generators or substations are located. The study found that during a cascading failure, in which heavily loaded substations fail in sequence, the failure of only about 280 of the most heavily loaded substations could cause a catastrophic failure of the entire grid. In contrast, a random failure of about 411 substations would result in a loss of power for only 60 percent of the electrical grid.

The authors suggest that schemes to reduce the electrical load on the most heavily loaded substations could reduce the electrical system's overall susceptibility to disruptions. Possible remediation strategies include increased redundancy focused on key substations and transmission lines, or more distributed generation, which would decrease the load on these key points.

Publication date: 09/27/2004