PacifiCorp Agrees to Join California ISO’s Extended Day-Ahead Market

by Paul Ciampoli
APPA News Director
December 13, 2022

PacifiCorp, a utility which operates in six states, recently announced its plan to join the Extended Day-Ahead Market (EDAM) being developed by the California Independent System Operator (CAISO), as well as the Western Power Pool’s Western Resource Adequacy Program (WRAP).

PacifiCorp is the first utility to sign on to the new Western day-ahead market.

PacifiCorp noted that it has been working with the CAISO and a wide range of stakeholders to develop the new day-ahead market. The EDAM builds upon CAISO’s existing Western Energy Imbalance Market.

Plans call for the EDAM to begin operation in 2024, subject to federal regulatory approval.

The current real-time WEIM optimizes the energy imbalances throughout the West by transferring energy between participants in 15-minute and 5-minute intervals throughout the day. The proposed EDAM builds on this real-time market by extending optimization to a high volume of resource commitments that must be made a day in advance, which are then re-optimized in the real-time WEIM as conditions change. 

CAISO on Dec. 8 noted that the final EDAM proposal was released on December 7 and the CAISO Board of Governors and Western EIM Governing Body will be briefed on the proposal on December 14.

The final proposal will be brought forward to the CAISO Board of Governors and WEIM Governing Body for a decision under the joint authority decision framework on February 1 and filed with the Federal Energy Regulatory Commission later in 2023.

Pacific Power, a PacifiCorp division, serves customers in Oregon, Washington and California.

PacifiCorp is also joining the Western Resource Adequacy Program, which is managed by the Western Power Pool. PacifiCorp said it has worked extensively with the Western Power Pool and other potential participants in the development of the WRAP, which is expected to provide regionwide reliability benefits to it participants by pairing regional diversity with common resource adequacy standards. 

This means WRAP participants will be held to common planning standards to serve winter and summer peak loads. The common planning standards and increased regional collaboration will create a pool of resources that can be used to serve load, if needed, thus increasing reliability for the entire region.