New Berkeley Lab report provides guidance to conduct enhanced resource adequacy assessments that support reliable decarbonization

October 17, 2023

Resource adequacy (RA) – the ability of the power system to meet load whenever and wherever is needed – has come under scrutiny with recent widespread interruptions due to weather events and the challenges brought on by decarbonization. Our report titled “A Guide for Improved Resource Adequacy Assessments in Evolving Power Systems” proposes a technical-institutional roadmap to assist regulators, system planners, and system operators with revising RA practices across specific components identified in our resource adequacy framework (see below). This paper will be discussed during a webinar held on October 27th, 2023, at 2:00 ET / 11:00 PT. Register here:

First, the paper provides a critical review of current RA assessment practices based on interviews with practitioners. A review of recent technical literature reveals that:

  • RA may need to expand beyond capacity adequacy to ensure energy adequacy – relevant for energy-limited resources such as storage – and potentially some form of ancillary service adequacy (e.g. enough ramping-up and ramping-down capability in the system).
  • Chronological hourly simulations for all hours in the year is the current best practice.
  • Metrics and models used do not reflect economic criteria in system operation and loss of load.
  • There is a need to improve representation of weather dependencies.

Second, the paper reviews existing practices involving resilience assessments in planning and RA reports from several private and public entities that plan generation and/or transmission infrastructure in the continental U.S. We find no systematic treatment of the costs of extreme weather, resilience metrics, methods, or outcomes for resource adequacy purposes.

Third, the study develops a model for probabilistic RA assessment to explore how key choices about how to model power system operations affect the values that are obtained for RA metrics. We find that:

  •  Dispatch schemes that ignore economic objectives can lead to accurate RA assessments when coordinated with detailed operational strategies.
  •  Multi-year data is critical to capture a wide variety of system conditions.
  • Neglecting transmission limits in RA assessment could lead to substantial underestimation of traditional “expected value” RA metrics.
  • New RA metrics that capture event-specific shortfall characteristics should be used as supplements to traditional metrics.

Finally, we examine RA assessments and use this information to propose a guide of evolving industry standards for resource adequacy assessments in resource planning and transmission planning. We report minimum, best, and frontier practices for temporal resolution of assessments, metrics and targets, weather data, load forecasting, characterization of variable renewable resources, characterization of transmission and market transactions, RA modeling and integration with planning processes, and capacity accreditation.

We expect the RA framework and roadmap developed in this work will be useful to coordinate action across stakeholders to improve RA assessments, the way these assessments inform investment decisions, and the performance of power system assets under stress conditions.

For questions on the report, please contact JP Carvallo (510-467-2954; [email protected]).

We appreciate the funding support of the U.S. Department of Energy’s Grid Deployment Office in making this work possible.