"Secure Grid '11 is the third in an ongoing series of exercises that National Defense University's Institute for National Strategic Studies (INSS) has conducted in conjunction with the Department of Homeland Security and U.S. Northern Command on the vulnerability of the North American Electric Grid. Previous exercises examined the ability of public and private institutions to work together to prevent and mitigate cyber and physical attacks on the grid. This year's game examined the threat posed to the grid by extreme solar weather. This type of event is considered a low-probability high-impact event, that is, while the probability of an event is low in any given year, the potential harm it could do to the United States and other countries is high. The exercise scenario was based on a space weather event with impacts similar in nature but less severe than those described by the National Academies of Science (NAS) 2009 Report Extended Summary 'Severe Space Weather Events -- Understanding Societal and Economic Impacts.' The NAS report described a possible geomagnetic disturbance (GMD) similar to a superstorm which occurred in 1921. This GMD produced a magnetic field change rate of 4800 nanoTeslas per minute (nT/min) at 50 degrees geomagnetic latitude. The NAS report explains that such an event occurring today could result in widespread power outages lasting for several years. By comparison, this exercise postulated a less severe event producing fewer long term power outages but still occurring at an unprecedented scale and duration. Additional scenario background is provided in the appendix to this document."
National Defense University: http://www.ndu.edu
Secure Grid '11: Electrical Grid Crisis Tabletop Exercise. National Defense University, Washington, D.C.. October 4-5, 2011