CAISO launches Extended Day-Ahead Market with PacifiCorp
Updated
Updated · Energy-Storage.news · May 5
CAISO launches Extended Day-Ahead Market with PacifiCorp
12 articles · Updated · Energy-Storage.news · May 5
The market went live on 1 May, extending CAISO’s Western trading model into day-ahead planning; Portland General Electric is due to join in October.
CAISO says batteries across the western US can participate in energy scheduling, frequency services and imbalance reserves, helping manage the solar-driven duck curve and improve reliability.
The launch builds on WEIM, which CAISO says has delivered $8.5 billion in benefits since 2014, while new safeguards aim to limit reliability risks and handle differing state greenhouse-gas rules.
Will CAISO's new market unify the West, or will a rival platform create a permanent grid divide?
Does connecting more states strengthen the Western grid or create a new single point of catastrophic failure?
Will the new energy market create a boom for batteries or erase the profits they are designed to capture?
Extended Day-Ahead Market (EDAM) Debuts, Promising $8.6 Billion in Benefits and Major Grid Reliability Gains
Overview
On May 1, 2026, CAISO and PacifiCorp launched the Extended Day-Ahead Market (EDAM), covering a six-state region to improve cost savings, grid reliability, and renewable energy integration. Building on the success of the Western Energy Imbalance Market, EDAM introduces a financially binding day-ahead market with new products like imbalance and ramping reserves, benefiting battery storage and reducing renewable curtailment by removing transmission wheeling charges. Governance is evolving from CAISO to the independent Regional Organization for Western Energy by 2028, ensuring fair regional representation. While operational complexity and governance challenges remain, EDAM’s expansion and innovative design promise a more efficient, reliable, and cleaner Western power grid.