Maintaining reliability while navigating unprecedented uncertainty: a synthesis of and guide to advances in electric sector resource adequacy

TL;DR

The paper addresses the mismatch between traditional resource adequacy (RA) frameworks and the deep uncertainty facing modern power systems with high renewable penetration and electrification. It defines RA, clarifies its relationship to resilience, and presents a taxonomy of uncertainty (parametric vs structural) with levels 1–5, advocating probabilistic RA for level-2 uncertainties and stress-testing for deeper uncertainties. It details operational details essential for accurate RA modeling (transmission, storage, flexible load), and links RA assessments to procurement via capacity accreditation using ELCC, discussing central planning and market-based pathways. The work provides a practical navigation guide and a roadmap for future research, including climate-integrated reliability planning, identification of critical operational details, and alternatives to ELCC-based accreditation to support reliable, low-cost procurement in an uncertain future.

Abstract

The reliability of the electric grid has in recent years become a larger concern for regulators, planners, and consumers due to several high-impact outage events, as well as the potential for even more impactful events in the future. These concerns are largely the result of decades-old resource adequacy (RA) planning frameworks being insufficiently adapted to the current types of uncertainty faced by planners, including many sources of deep uncertainty for which probability distributions cannot be defensibly assigned. There are emerging methodologies for dealing with these new types of uncertainty in RA assessment and procurement frameworks, but their adoption has been hindered by the lack of consistent understanding of terminology related to RA and the related concept of resilience, as well as a lack of syntheses of such available methodologies. Here we provide an overview of RA and its relationship to resilience, a summary of available methods for dealing with emerging types of uncertainty faced by RA assessment, and an an overview of procurement methodologies for operationalizing RA in the context of these types of uncertainty. This paper provides a synthesis and guide for both researchers and practitioners seeking to navigate a new, much more uncertain era of power system planning.

Figures (7)

• Figure 1: A schematic of the various types of uncertainty affecting power system reliability, organized into uncertainty affecting both the supply and demand sides.
• Figure 2: The relationship between resilience, and its key components in the context of the electric grid: RA, operating reliability, and contingency preparedness.
• Figure 3: A taxonomy of the 5 levels of parametric uncertainty as conceived by Cox cox_jr_confronting_2012 and adapted by Thissen thissen_public_2013.
• Figure 4: A schematic of the dimensions of uncertainty presented here, along with a depiction of where the key types of uncertainty affecting power system RA fall in this categorization.
• Figure 5: A schematic of the four categories of operational details discussed in this section, showing the current industry standard practices and best practices associated with each, along with the estimated direction and magnitude of impact on reliability if each is left out. A "+" in this last column means that leaving this detail out will lead to an overestimate of reliability.