If terrorists caused a blackout in Los Angeles County, various forms of resilience would give electricity customers the ability to mute the potential shock to their businesses by as much as 86 percent.

These are the findings of a new study by scientists affiliated with the University of Southern California's (USC's) Center for Risk and Economic Analysis of Terrorism Events (CREATE). As the sixth anniversary of Sept. 11, 2001, approaches, the conclusions from this study should help utility authorities with their emergency planning.

The study --"Business Interruption Impacts of a Terrorist Attack on the Electric Power System of Los Angeles: Customer Resilience to a Total Blackout" -- appears in a special homeland security issue of the peer-reviewed journal Risk Analysis (Vol. 27, No. 3, 2007), which is published by the McLean, Virginia-based Society for Risk Analysis.

The study on the direct and indirect economic impacts of an extended power outage caused by a terrorist attack in Los Angeles was conducted by Adam Rose of USC-CREATE; Gbadebo Oladosu of Oak Ridge National Laboratory, Oak Ridge, Tennessee, and Shu-Yi Liao of National Chung Hsing University, Taichung, Taiwan. Given the ability of terrorists to target maximum damage, they simulated a total power blackout lasting two weeks. Here is what their research concluded:

-- A two-week total electricity blackout would amount to a business interruption loss of $20.5 billion without any customer resilience, but only $2.8 billion with the inclusion of several types of resilience, most prominently the rescheduling of production after electric service is restored.

-- Inherent aspects of the electricity-economy relationship (e.g., inter-fuel substitution) and adaptive behavioral responses (e.g., conservation, on-site electricity generation) also can help deliver this 86-percent reduction in potential disruption impacts.

-- Electric power systems are relatively difficult to safeguard. With the exception of nuclear power plants, until recently, no generating station, sub-station, transmission or distribution lines have been constructed in the U.S. with a major emphasis on protection from terrorism.

The authors did not consider the value of lives lost, increased crime, psychological trauma, some infrastructure costs, and property damage.

"There is strong indication that people learn from disaster experiences and that options implemented for one type of disaster apply to others (e.g., purchase of backup electric generators in the aftermath of the Northridge Earthquake)," the authors said. "Thus, there is some cause for optimism that resilience to disasters will increase over time."

This research was supported by grants from the U.S. Department of Homeland Security and, in the case of the research on a possible blackout, by a grant from the National Science Foundation-sponsored Multidisciplinary Center for Earthquake Engineering Research.