Control center modernization is enhancing reliability
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The ISO commends the California Legislature, Governor Newsom, and the diverse coalition of stakeholders for their leadership in advancing this important legislation. This marks a crucial next step toward independent governance of Western electricity markets — a milestone shaped by years of successful and evolving regional collaboration.
As the Pathways Committee develops the framework for the new regional organization, the ISO will coordinate closely to ensure alignment with legislative requirements. The ISO remains fully committed to the successful launch of the Extended Day‑Ahead Market and will offer technical support throughout the transition.
The western energy markets encompass the Western Energy Imbalance Market (WEIM) and the Extended Day-Ahead Market (EDAM). Developed in partnership with stakeholders from across the West, these markets have been designed to reflect and respect the region’s diversity.
A west-wide energy market is essential for the efficient and reliable distribution of electricity across the West. Coordinated management of diverse resources across a broad footprint has led to substantial cost savings to customers, improved reliability, and significant environmental benefits.
The Western Energy Imbalance Market is a stand-alone market platform for balancing authorities in the West, enabling real-time balancing of supply and demand leveraging the diverse resources in the region. Since its launch in 2014, WEIM has expanded to include 21 balancing authorities outside of the ISO across 11 western states.
Learn more about WEIM
Set to launch in 2026, the Extended Day-Ahead Market extends market operations into the day-ahead timeframe. Available to entities participating in WEIM, EDAM will assist balancing authorities in the West in pre-positioning supply to meet forecasted electric demand for the following day.
Learn more about EDAM