Americans' safety, productivity, comfort, and convenience depend on the reliable supply of electric power. The electric power system is a complex "cyber-physical" system composed of a network of millions of components spread out across the continent. These components are owned, operated, and regulated by thousands of different entities. Power system operators work hard to assure safe and reliable service, but large outages occasionally happen. Given the nature of the system, there is simply no way that outages can be completely avoided, no matter how much time and money is devoted to such an effort. The system's reliability and resilience can be improved but never made perfect. Thus, system owners, operators, and regulators must prioritize their investments based on potential benefits. Enhancing the Resilience of the Nation's Electricity System focuses on identifying, developing, and implementing strategies to increase the power system's resilience in the face of events that can cause large-area, long-duration outages: blackouts that extend over multiple service areas and last several days or longer. Resilience is not just about lessening the likelihood that these outages will occur. It is also about limiting the scope and impact of outages when they do occur, restoring power rapidly afterwards, and learning from these experiences to better deal with events in the future.

Americans' safety, productivity, comfort, and convenience depend on the reliable supply of electric power. The electric power system is a complex "cyber-physical" system composed of a network of millions of components spread out across the continent. These components are owned, operated, and regulated by thousands of different entities. Power system operators work hard to assure safe and reliable service, but large outages occasionally happen. Given the nature of the system, there is simply no way that outages can be completely avoided, no matter how much time and money is devoted to such an effort. The system's reliability and resilience can be improved but never made perfect. Thus, system owners, operators, and regulators must prioritize their investments based on potential benefits. Enhancing the Resilience of the Nation's Electricity System focuses on identifying, developing, and implementing strategies to increase the power system's resilience in the face of events that can cause large-area, long-duration outages: blackouts that extend over multiple service areas and last several days or longer. Resilience is not just about lessening the likelihood that these outages will occur. It is also about limiting the scope and impact of outages when they do occur, restoring power rapidly afterwards, and learning from these experiences to better deal with events in the future.

" In light of increasing threats to the nation's electricity grid, national policies have stressed the importance of enhancing the grid's resilience-its ability to adapt to changing conditions; withstand potentially disruptive events, such as the loss of power lines; and, if disrupted, to rapidly recover. Most of the electricity grid is owned and operated by private industry, but the federal government has a significant role in promoting the grid's resilience. DOE is the lead agency for federal grid resiliency efforts and is responsible for coordinating with DHS and other relevant federal agencies on these efforts. GAO was asked to review federal efforts to enhance the resilience of the electricity grid. This report (1) identifies grid resiliency efforts implemented by federal agencies since 2013 and the results of these efforts and (2) examines the extent to which these efforts were fragmented, overlapping, or duplicative, and the extent to which agencies had coordinated the efforts. GAO reviewed relevant laws and guidance; identified a list of federal grid resiliency efforts; sent a questionnaire to officials at DOE, DHS, and FERC to collect information on each effort and its results; analyzed questionnaire responses and agency documents to assess whether federal efforts were fragmented, overlapping, or duplicative and how agencies coordinated those efforts; and interviewed agency"

The Resilience of the Electric Power Delivery System in Response to Terrorism and Natural Disasters is the summary of a workshop convened in February 2013 as a follow-up to the release of the National Research Council report Terrorism and the Electric Power Delivery System. That report had been written in 2007 for the Department of Homeland Security, but publication was delayed because of security concerns. While most of the committee's findings were still relevant, many developments affecting vulnerability had occurred in the interval. The 2013 workshop was a discussion of the committee\'s results, what had changed in recent years, and how lessons learned about the grid's resilience to terrorism could be applied to other threats to the grid resulting from natural disasters. The purpose was not to translate the entire report into the present, but to focus on key issues relevant to making the grid sufficiently robust that it could handle inevitable failures without disastrous impact. The workshop focused on five key areas: physical vulnerabilities of the grid; cybersecurity; mitigation and response to outages; community resilience and the provision of critical services; and future technologies and policies that could enhance the resilience of the electric power delivery system. The electric power transmission and distribution system (the grid) is an extraordinarily complex network of wires, transformers, and associated equipment and control software designed to transmit electricity from where it is generated, usually in centralized power plants, to commercial, residential, and industrial users. Because the U.S. infrastructure has become increasingly dependent on electricity, vulnerabilities in the grid have the potential to cascade well beyond whether the lights turn on, impacting among other basic services such as the fueling infrastructure, the economic system, and emergency services. The Resilience of the Electric Power Delivery System in Response to Terrorism and Natural Disasters discusses physical vulnerabilities and the cybersecurity of the grid, ways in which communities respond to widespread outages and how to minimize these impacts, the grid of tomorrow, and how resilience can be encouraged and built into the grid in the future.

The electric power delivery system that carries electricity from large central generators to customers could be severely damaged by a small number of well-informed attackers. The system is inherently vulnerable because transmission lines may span hundreds of miles, and many key facilities are unguarded. This vulnerability is exacerbated by the fact that the power grid, most of which was originally designed to meet the needs of individual vertically integrated utilities, is being used to move power between regions to support the needs of competitive markets for power generation. Primarily because of ambiguities introduced as a result of recent restricting the of the industry and cost pressures from consumers and regulators, investment to strengthen and upgrade the grid has lagged, with the result that many parts of the bulk high-voltage system are heavily stressed. Electric systems are not designed to withstand or quickly recover from damage inflicted simultaneously on multiple components. Such an attack could be carried out by knowledgeable attackers with little risk of detection or interdiction. Further well-planned and coordinated attacks by terrorists could leave the electric power system in a large region of the country at least partially disabled for a very long time. Although there are many examples of terrorist and military attacks on power systems elsewhere in the world, at the time of this study international terrorists have shown limited interest in attacking the U.S. power grid. However, that should not be a basis for complacency. Because all parts of the economy, as well as human health and welfare, depend on electricity, the results could be devastating. Terrorism and the Electric Power Delivery System focuses on measures that could make the power delivery system less vulnerable to attacks, restore power faster after an attack, and make critical services less vulnerable while the delivery of conventional electric power has been disrupted.

In light of increasing threats to the nation's electricity grid, national policies have stressed the importance of enhancing the grid's resilience—its ability to adapt to changing conditions; withstand potentially disruptive events, such as the loss of power lines; and, if disrupted, to rapidly recover. Most of the electricity grid is owned and operated by private industry, but the federal government has a significant role in promoting the grid's resilience. DOE is the lead agency for federal grid resiliency efforts and is responsible for coordinating with DHS and other relevant federal agencies on these efforts. GAO was asked to review federal efforts to enhance the resilience of the electricity grid. This report (1) identifies grid resiliency efforts implemented by federal agencies since 2013 and the results of these efforts and (2) examines the extent to which these efforts were fragmented, overlapping, or duplicative, and the extent to which agencies had coordinated the efforts. GAO reviewed relevant laws and guidance; identified a list of federal grid resiliency efforts; sent a questionnaire to officials at DOE, DHS, and FERC to collect information on each effort and its results; analyzed questionnaire responses and agency documents to assess whether federal efforts were fragmented, overlapping, or duplicative and how agencies coordinated those efforts; and interviewed agency officials and industry group representatives. This report contains no recommendations.