2027 Effective Flexible Capacity values for Resource Adequacy Resources

The California ISO (ISO) has posted the draft final Effective Flexible Capacity Report for Compliance Year 2027 to the Resource Adequacy webpage. 

Comments and suggestions related to the EFC values must be submitted through CIDI with the following subject line “2027 EFC questions” by Sep. 3, 2026.

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 on 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 Sep. 3, 2026, comments deadline and the ISO will evaluate if the resource can be added to the 2027 final EFC list.

If no modifications are requested for EFC by Sep. 3, 2026, the ISO will use the posted values for the RA compliance year 2027.

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

Please contact Melanie Bogen at mbogen@caiso.com with any questions.