Extended Day-Ahead Market (EDAM)

Building on the demonstrated economic, reliability, and environmental benefits of the Western Energy Imbalance Market (WEIM), the California ISO’s EDAM will optimize the use of existing transmission and resources in the much larger day-ahead timeframe across an expanded Western footprint.

EDAM will open the door to significantly improved economic benefits through the commitment of least-cost generation across the market’s broad geographic footprint and enable improved situational awareness across balancing authority areas, enhance reliability, and lower greenhouse gas emissions.

Currently, four entities have informed the ISO of their interest in joining the EDAM: PacifiCorp, Balancing Authority of Northern California, Portland General Electric, Los Angeles Department of Water & Power. A fifth entity, Idaho Power has indicated it is leaning toward EDAM as its preferred day-ahead market.


Read the EDAM fact sheet.

Visit our EDAM Forum webpage to view presentations and the meeting recording.

Read the news release about federal regulators accepting changes to the ISO’s tariff allowing EDAM to move forward.

View comments from energy leaders across the West about the EDAM’s progress.

Follow and participate in the EDAM Policy Initiative.

Contact us

ISO staff is here to assist you. If you need additional information on participating in EDAM, please contact:


Adam Schultz