Secure Grid '11 Overview
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.
Secure Grid '11 was held on October 4-5, 2011 at National Defense University in Washington D.C. and attended by leading figures from industry, state and federal agencies, and the scientific community. The exercise entailed a crisis simulation with the goal of exploring how private and government agencies would respond to a solar storm causing widespread damage to the grid, how they might cooperate during such a crisis, and to explore what steps could be taken to mitigate such severe events. The scenarios in the exercise were designed by a team of experts from industry, the Department of Homeland Security, U.S. Northern Command, and the National Oceanic and Atmospheric Administration.
The tabletop exercise was conducted in three modules using a guided seminar structure to explore relevant questions and issues. After opening comments on the morning of October 4th, participants were assigned to four separate breakout groups containing a diverse mix of representatives. Each group was instructed to address a specific set of broad questions in each stage, which consisted of an early warning stage, an event occurrence stage, and a post-event damage assessment/consequence management and mitigation stage. Groups were given two hours to address each stage over the course of the first day. The second day, October 5th, consisted of post-exercise analysis, which brought each team into plenary session to debrief the entire group on their findings, insights, and recommendations.
On the second day of the event, all participants were able to hear and discuss the findings of the individual groups. The afternoon outbrief session provided a forum to present the game's results to senior officials.
Although the details of the lessons learned and recommendations that resulted from each group's participation and immersion in the experience are discussed in detail below, the most important findings are summarized here.
The broadest consensus reached by the participants was that in an event as severe as the one posited by the exercise, prevention is preferable to response and recovery. Improvements in early warning, especially the replacement of the Advanced Composition Explorer (ACE) satellite, hardening of critical equipment, stockpiling of replacement transformers, and improved resilience in the grid were identified as crucial components of any effort to minimize the probability of long term grid outages resulting from a GMD.
The biggest unresolved question concerns the type of damage such an event might cause to critical grid components, especially large extremely high voltage (EHV) transmission transformers. Although the effects of ground induced current (GIC) on transformers have been studied, significant technical uncertainty surrounds questions regarding whether typical in service transformers would catastrophically fail in GMD conditions. This factor complicates efforts to accurately estimate the possible extent of equipment damage and related grid failure that might occur. EHV transformers are very large, extremely heavy, and highly difficult to transport to the remote sites where they are typically installed. The numbers of existing spares are not sufficient to recover from a GMD that damages a significant fraction of the national or international fleet. Global supply chains would be unable to produce replacement EHV transformers at a rate needed to meet demand if large numbers were suddenly required to recover from a GMD affecting several industrialized countries.
Extensive stockpiling of replacement transformers is a highly expensive proposition, both in terms of manufacture and storage. Further, given a catastrophic event, the just-in-time production systems currently in place would be vulnerable to the cascading effects of a broad, long-term power outage, making it difficult to obtain replacements post-event. These two factors create a conundrum in which stockpiling prior to an event is expensive and problematic, while replacement post-event would also be highly problematic and extremely time consuming when time is of the essence. Thus, neither option is palatable for industry to address, particularly given the low-probability of such an event occurring. Therefore, it was the consensus of the exercise participants that industry especially requires a more developed understanding of exactly how likely such an event is, as well as how much damage is likely to occur from a severe GMD.
To read the full report, please click here.
The views contained in this report are those expressed during the tabletop exercise by participants and do not reflect the official policy or position of National Defense University, the Department of Defense, or the U.S. Government.