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The Extended Day-Ahead Market is designed to deliver significant reliability, economic, and environmental benefits to utilities across the West.

Extended Day-Ahead Market (EDAM)

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

EDAM opens 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.

Western energy markets observations

Resources

Participants

Entities leaning towards EDAM

Implementation documents

Public Service Company of New Mexico (PNM)

Imperial Irrigation District (IID)

Turlock Irrigation District (TID)

Los Angeles Department of Water & Power (LADWP)

Balancing Authority of Northern California (BANC)

PacifiCorp

Portland General Electric

Contact us

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

Melissa Skelton
MSkelton@caiso.com

Map of the Western US, showing Extended Day-Ahead Market current and future participants and existing Western Energy Imbalance Market participants.

*These entities have publicly indicated a leaning towards EDAM as their preferred day-ahead market.
Map boundaries are approximate and for illustrative purposes only. Copyright ©2026 California ISO

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