Council sets resource adequacy thresholds for Ninth Power Plan

 Following an extensive public engagement process with partners across the region, in 2023 Council adopted a new, multi-metric approach to planning for the Pacific Northwest power system’s resource adequacy. This new approach better protects the system’s resource adequacy, helping to ensure it has the power supply needed to meet periods of peak demand, including during a heat wave or cold snap, as well as the day-to-day energy needs of residents, businesses, and industries across the region.

At its April meeting in Portland, the Council set the thresholds for each metric, which are intended to protect the system from outages that are too frequent, too large, or too long in duration. These capture and reflect risk thresholds the region was comfortable with, based on the Council’s public engagement in its advisory committees and other processes over the past several years. (Read presentation | watch video)

For many years, the Council – like most power system planners in the U.S. – used a single criterion to ensure the Northwest’s electricity grid had adequate resources to meet daily energy needs as well as periods of peak demand. The lone criterion was a probabilistic metric, which worked well for a power system whose predominant resources were hydropower, thermal plants, and energy efficiency, where generation uncertainty was minimal. As the resource mix shifts in the Northwest and more renewable sources come online, a new approach was needed.

The multi-metric adequacy framework now provides insights into the frequency, duration, and magnitude of potential shortfall events. An adequate system means all metrics stay within their respective thresholds. This is a major advancement that will help the Council and the region plan for needed solutions in the Pacific Northwest. The Council developed this multi-metric approach through public engagement with utilities, energy providers, state and federal agencies, regulators, technical experts, tribes, and many others.

The Council uses one frequency metric:

• Frequency – Loss of load events (LOLEV) is used to prevent overly frequent use of emergency measures.

The next three metrics are designed to protect against extreme shortfall events 39 out of 40 years using the 97.5^th Value at Risk percentile. It means adequacy events do not last too long or have large magnitudes in most years.

• Duration – Duration Value at Risk sets a limit to protect against prolonged use of emergency measures. This helps to capture the risk of a summer heatwave or a winter storm.
• Magnitude – Peak Value at Risk protects against large magnitude emergency measure use.
• Magnitude – Energy Value at Risk protect against large aggregate use of emergency measures during a year.

For the upcoming Ninth Power Plan, the Council set the threshold for the frequency (LOLEV) metric at 0.1 in summer, 0.1 in winter, and 0.2 annually. This means it would limit adequacy challenges to one summer event and one winter event in 10 years, and one in five years overall.

For the protection against the more extreme shortfall events, the Council set the thresholds for duration at eight hours, for peak at 1,200 MW, and for energy at 9,600 MWh. This means that in an adequate regional power system, the adequacy standards will be protecting against events that at or below these thresholds 39 out of 40 years.

Council staff honored for adequacy work

Recently, the Energy Systems Integration Group - ESIG honored Council staff Dor Hirsh Bar Gai and Dan Hua, alongside former Council staff John Fazio with 2025 Excellence Awards for work on a national task force focusing on the need for power system planners in North America and around the world to adopt new resource adequacy criteria to better protect electricity grids from outages and adequacy challenges.

Hirsh Bar Gai, Hua and Fazio served on the task force, whose work culminated in a report published last year. In March, Hirsh Bar Gai traveled to Austin, Tex., to accept a 2025 Excellence Award from ESIG.

• Read more about how the Council plans for resource adequacy.
• Read the ESIG task force’s 2024 report.