2026 Effective Flexible Capacity values for Resource Adequacy Resources

The California ISO has posted the preliminary 2026 Resource Adequacy EFC data on its website. 

Comments and suggestions related to the EFC values must be submitted through CIDI with the subject line, “2026 EFC questions” by Aug. 20, 2025.

The ISO has not received attestation letters for several resources identifying the category of flexible RA the resource is physically capable of providing.  A copy of the attestation language is available at the resource adequacy webpage. Without this information, the ISO is unable to assign a flexible RA category to the resource and the resource is thus excluded from the draft list. Scheduling coordinators for such resources may provide an attestation by the Aug. 20 comments deadline and the ISO will evaluate if the resource can be added to the 2026 final EFC list.

If no modifications are requested for EFC by Aug. 20, 2025, the ISO will use the posted values for the RA compliance year 2026.

Scheduling coordinators may submit comments to the California Public Utilities Commission (CPUC) at RAFiling@cpuc.ca.gov.