INSIGHTi Electric Reliability and Power System Resilience May 2 2018 Electricity is vital to the commerce and daily functioning of the United States Nowhere has this been demonstrated more significantly than in Puerto Rico and the U S Virgin Islands where the effects of the widespread loss of electricity after Hurricane Maria are still being felt Subsequently there has been much discussion about electric system reliability and how electric systems can improve resiliency And while the effects were not as catastrophic the impacts of the Bomb Cyclone in January 2018 caused some to question whether the increasing retirements of coal and nuclear power plants could lessen fuel diversity and affect electric power system resilience While electric system reliability and system resiliency are related they differ both in scope and regulatory requirement Reliability according to the U S Department of Energy DOE is the ability of the system or its components to withstand instability uncontrolled events cascading failures or unanticipated loss of system components Resilience as defined by DOE is the ability of a system or its components to adapt to changing conditions and withstand and rapidly recover from disruptions Mandatory and Enforceable Rules for Reliability Congress gave the Federal Energy Regulatory Commission FERC authority to oversee the reliability of the bulk-power system under the Energy Policy Act of 2005 P L 109-58 EPACT05 Reliability standards were added as Section 215 of the Federal Power Act FPA to help ensure the reliable operation of the bulk power system so that “instability uncontrolled separation or cascading failures” will not occur as a result of a sudden disturbance Section 215 of the FPA also defines FERC’s jurisdiction in terms of “users owners and operators” of the bulk power system FERC can approve or remand back reliability standards proposed by the Electric Reliability Organization which bulk-power system owners and operators must follow to help ensure the reliable operation of the grid Reliability standards address programs ranging from vegetation clearances in electric transmission line rights-of-way to policies and procedures for critical infrastructure protection focused on the cyber- and physical security of power plants and supporting facilities The standards are both mandatory and enforceable in that violators of reliability rules may be subject to a civil fine of up to $1 000 000 per violation for each day that it Congressional Research Service https crsreports congress gov IN10895 CRS INSIGHT Prepared for Members and Committees of Congress Congressional Research Service 2 continues However Commission-approved reliability standards are only applicable to the continental United States and not to U S territories such as Puerto Rico Additionally DOE’s Office of Electricity Delivery and Energy Reliability has responsibility for the security and reliability of critical energy infrastructure not just electricity in emergency situations In the United States there are two main indices used to measure reliability The system average interruption duration index SAIDI represents the average amount of time per year that power supply to a customer is interrupted expressed in minutes per customer per year The system average interruption frequency index SAIFI represents the average number of times per year that the supply to a customer is interrupted expressed as interruptions per customer per year However there is a lack of consistency in how the inputs to these indices are measured since some jurisdictions consider storm-related outages as “extreme” or unusual events and thus do not include these in power outage statistics Resilience Must Be Planned According to the DOE there are no commonly used metrics for measuring grid resilience Electric system resilience is not mandated by federal law but the ability of the system to adapt to changing conditions and recover rapidly from disruptions is a key attribute of electric system reliability A 2016 report from several of DOE’s national laboratories focused on this changing environment and the need to maintain a resilient power system The report identified risks ranging from weather events that disrupt transmission or distribution to high impact low frequency HILF risks such as catastrophic hurricanes The report also built upon previous developments identified by DOE in the energy sector including growing potential threats from climate change energy security transitions from coal to natural gas generation increased deployment of distributed and renewable generation and rising investments to modernize the energy grid While the report acknowledged that electric power systems “are currently well-equipped to effectively manage a broad range of threats ” it recognized that some risks remain challenging and that “resilience efforts should shift toward these more complex risk management challenges ” Some of the key risks to resilience identified include    HILF threats associated with natural hazards particularly weather or space weather of historic intensity or large-scale physical cyber or electromagnetic attacks Combined or blended threats associated with simultaneous exposure of the electric grid to one or more natural threats in combination with a physical or cyberattack Threats that affect vulnerable components of the electricity system or that exceed critical thresholds For example distribution networks are often a weak link in the electric grid but disruptions and outages associated with distribution are often localized The report provided a number of recommendations “to guide future decision-making to enhance resilience of the U S electricity system ” These recommendations included Congressional Research Service     3 Build a greater understanding of HILF events and capability to incorporate HILF threats into risk assessment Scenario-based planning to explore multiple contingencies can be used to stress test the system and identify gaps in resilience Develop a robust and scalable system of resilience metrics for the electricity system Increase their capacity to assess and manage risks and their uncertainties which may change over time and geographic areas Future changes in not only the climate but also population technology and societal preferences have important implications for resilience Institute policies and practices that can help to streamline assessment and decisionmaking while enhancing coordination and communication can be just as important to resilience as the development of robust infrastructure and assets How electric power systems incorporate resiliency into reliability planning will depend on the evaluation of risk to the system and the financial and other resources available to system planners Given the potential consequences of long-term electric power failures Congress may consider further how various electric power systems incorporate resilience in reliability planning Author Information Richard J Campbell Specialist in Energy Policy Disclaimer This document was prepared by the Congressional Research Service CRS CRS serves as nonpartisan shared staff to congressional committees and Members of Congress It operates solely at the behest of and under the direction of Congress Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role CRS Reports as a work of the United States Government are not subject to copyright protection in the United States Any CRS Report may be reproduced and distributed in its entirety without permission from CRS However as a CRS Report may include copyrighted images or material from a third party you may need to obtain the permission of the copyright holder if you wish to copy or otherwise use copyrighted material IN10895 · VERSION 4 · NEW