The ISO provides resources and learning opportunities for the Western Energy Imbalance Market and Extended Day-Ahead Market participants and their transition customers

Resources

Western Energy Imbalance Market (WEIM) Participants

These resources are intended for WEIM entities and participating generators that are directly involved in the Western Energy Imbalance Market.

Business Practice Manuals

Business Practice Manuals contain implementation details through which the California ISO and market participants conduct business in accordance with the Tariff. The Business Practice Manual for Western Energy Imbalance Market contains information about all WEIM entity types.

Tariff

The Western Energy Imbalance Market is governed by the California ISO (ISO) FERC-approved Tariff. Each section or appendix of the tariff is maintained and updated independently according to effective dates of the FERC accepted tariff amendment

Integrate with the ISO full network model

The network model defines system parameters, price node and market scheduling limit mappings and planned network model updates.

Western Energy Imbalance Market Full Network Model Schedule - 2025 07/22/2025, 11:05 AM
Western Energy Imbalance Market Full Network Model Schedule - 2026 05/21/2025, 11:29 AM
Modeling Submission Checklist 09/10/2024, 4:31 PM
Western Energy Imbalance Market Generator Resource Data Template Version 18.0 08/02/2024, 2:08 PM
Western Energy Imbalance Market Full Network Model Late Scope Change Request Form 03/30/2023, 9:49 AM
Western Energy Imbalance Market Interchange Definition Template 12/16/2020, 10:24 AM
Western Energy Imbalance Market Full Network Model Scope Template 11/02/2020, 3:43 PM

Computer Based Training (CBT)

Learning center courses

Western Energy Imbalance Market training

Explore topics pertaining to the real-time energy imbalance market that enables participants to buy and sell energy when needed.