System planners should evaluate the need for flexibility as conventional generation retirements are considered by industry and policymakers, according to NERC’s 2020 State of Reliability report.
Furthermore, retirement planning studies should consider interconnection-level impacts and sensitivity assessments associated with the loss of critical transmission paths and the loss of local generation in larger load pockets, the report said.
As noted in the document, the purpose of the annual report is to provide objective and concise information to policymakers, industry leaders, and the NERC Board of Trustees on issues affecting the reliability and resilience of the North American bulk power system (BPS). Analysis in the report is based on 2015-2019 data and provides a basis to evaluate 2019 performance relative to performance over the last five years, NERC noted.
NERC recommended that the Electric Reliability Organization (ERO) and industry continue improving their ability to model, plan, and operate a system with a significantly different resource mix, with priority given to understanding the implications of frequency response under low inertia conditions; contributions of inverter-based resources to essential reliability services; as well as increasing protection system and restoration complexities with increased inverter-based resources.
The ERO and industry should also develop comparative measurements and metrics to understand the different dimensions of resilience — for instance, withstanding the direct impact, managing through the event, recovering from the events, and preparing for the next event — during the most extreme events and how system performance varies with changing conditions, NERC said.
Another recommendation called for the ERO and industry to continue to work closely together to understand and share information on cyber and physical security threats and mitigate the risks posed by those threats through various approaches, including resilient system design, consequence-informed planning and operation, as well as practicing response and recovery processes.
NERC also noted that overall, 2019 was a “very good” year for BPS reliability, with performance trends in terms of generation, transmission, as well as protection and control measures being generally positive.
The electricity sector is undergoing significant and rapid changes to the generation resource mix that present new challenges and opportunities for reliability, NERC said, adding that persistent cyber and physical security threats present critical challenges to BPS reliability that require industry and regulators to remain vigilant.
Noting that metrics showed improvement in numerous areas, NERC said, for instance, that the impact of transmission outages on the bulk electric system (BES) is decreasing, and that the number of automatic transmission outages from AC circuits and transformers caused by human error is decreasing.
Of metrics that indicate declining performance, NERC noted that the count and severity of energy emergency alerts (EEAs) is increasing, and that the Planning Reserve Margin continues to not meet expected thresholds in some areas.
As noted in the report, the Planning Reserve Margin determines the amount of committed capacity a given assessment area expects compared to the projected net internal demand. Planning Reserve Margins cannot precisely predict capacity deficiencies, but areas below the Reference Margin Level indicate a higher probability of a capacity deficiency occurring than the desired target of 1-day-in-10 years, NERC said.
NERC also discussed key findings for 2019, including that in Texas, the projected capacity deficit remains a reliability risk in 2020, but better than expected performance from the generation fleet helped meet 2019 summer peak demand. NERC noted that Texas continues to have insufficient resources to meet the “Reference Margin Level” but still successfully met demand throughout the 2019 summer season. Despite having set a new system-wide peak demand record of 74,666 MW on Aug. 12, 2019, sufficient resources were available throughout the peak day to remain above reserve requirements, and that was primarily due to higher than average contribution from wind generation resources, as well as lower than average total generation outages, NERC said.
Another key finding is that NERC and industry stakeholders are advancing solutions to the addition of more inverter-based resources, which include solar photovoltaic (PV), battery storage, and many forms of wind generation.
As noted in the report, over the past 10 years, more than 100 GW of conventional generation capacity has retired, and 246 GW, 91 GW, and 30 GW of new natural gas, wind, and solar generation capacity has been added to the BPS, respectively.
Some inverter-based resource performance issues have been significant enough to result in grid disturbances that affect the reliability of the BPS, such as the tripping of a number of BPS-connected solar PV generation units that occurred during the 2016 Blue Cut fire and 2017 Canyon 2 fire disturbances in California, NERC said. The ERO continues to focus resources on addressing potential reliability issues associated with the ever-increasing penetration of inverter-based resources, NERC noted.
NERC added that despite continually evolving threats to the BPS, no cyber or physical security incidents led to unauthorized control actions or loss of load occurred in 2019. The industry should continue to drive improvements in its security posture through technological hardening, growing a culture of security, and increasing effective information exchange between entities, the Electricity Information Sharing and Analysis Center (E-ISAC), and trusted partner organizations, NERC said.
Three threat sources dominated the physical security environment throughout 2019, including activist group threats, NERC said, noting that social media campaigns tied to environmental, social, and political causes dominated 2019 and occasionally targeted the electricity industry. While those campaigns rarely escalated to direct action, the potential for associated physical security threats remains, NERC said.
NERC also noted that certain underlying tactics observed across the broad cybersecurity industry continued through 2019, with those tactics including social engineering, which involves targeted phishing and other forms of social engineering that exploit human fallibility and trust to gain an initial foothold into targeted systems. The number of cybersecurity events shared with the E-ISAC from all sources nearly tripled in 2019 to 684. The typical organization experiences thousands or millions of events every day, with very few of those events being incidents, NERC said, adding, “Therefore, while the significant increase in available information in 2019 has improved our understanding of the environment, it does not necessarily mean that there were more (or more impactful) incidents in 2019 compared to prior years.”
Among other things, NERC also noted that an in-depth evaluation of any impacts due to the COVID-19 pandemic on BPS operations in 2020 will be a focus of the 2021 State of Reliability report, which is typically published mid-year.