Parallel Operations: another milestone on the way to EDAM “Go Live”

We are very pleased to announce the official start of the Extended Day-Ahead Market (EDAM) parallel operations, which began the week of Feb. 3, 2026 and will continue through the market’s “Go Live” in May. This milestone represents a major achievement for the California ISO (CAISO) and our first EDAM partner, PacifiCorp. The scale of this effort is enormous, with multiple systems and dependencies and highly coordinated activities that affect every corner of our organization. Reaching this stage reflects the incredible collaboration, expertise and dedication across all ISO business units, and by our partners at PacifiCorp.

With parallel operations now underway, our emphasis shifts from the technical functions and system integration testing toward operator and business readiness. This phase is about validating end-to-end EDAM market functions and processes, including settlements, in a production-like setting. Both the ISO and PacifiCorp will be tracking progress using jointly established readiness criteria.

On the road to EDAM "Go Live", launching parallel operations covers several high-priority implementation projects:

• Day-Ahead Market Enhancements: a new imbalance reserve product intended to ensure sufficient ramping capacity is available in the real-time market. Given the uncertainty about loads and generation resources, the new reliability capacity market product is intended to schedule resources more efficiently to meet the difference between cleared net load and the net load forecast.
• EDAM: with multi-balancing areas market optimization, we can economically and reliably schedule resources in the EDAM market footprint.
• EDAM ISO Balancing Authority Area participation rules: this includes the net EDAM export transfer constraint, which is designed to allow each participating balancing area to manage the amount of supply exported to support EDAM transfers. Also, it includes the financial implications of passing or failing the resource sufficiency evaluation (RSE).
• PacifiCorp onboarding: this includes master file registration and EDAM-related data submissions as well as EDAM considerations on adjacent Western Energy Imbalance Market (WEIM) entities.

With our partners and stakeholders, we have designed, built, and operated the highly successful WEIM for real-time operation. The market has strengthened reliability and resulted in more than $8 billion in financial benefits to participants and their customers since 2014.

Now, with EDAM, we have designed, built and are in parallel operations with a soon-to-launch market that will meet the diverse needs of Western stakeholders. It will build on those WEIM’s benefits and fortify reliability with a day-ahead plan based on physics and economics.