Information Technology

The California ISO’s Variable Operations and Maintenance Cost Review (VOMCR) implementation has specific critical dates to meet in order to include corresponding changes in Master File.

• Market Participants to complete Variable Operations and Maintenance adders negotiations by end of day Dec. 17, 2021 for activation effective Jan. 1, 2022.
• Master File data freeze begins on Dec. 18, 2021.
• The ISO will prepare Master File data for Master File bulk upload before Dec. 20, 2021.
• The ISO will upload Master File data in between Dec, 20, 2021, to Dec. 22, 2021.
• The Master File data freeze ends and Master File will be available to market participants on Dec. 23, 2021.
• The ISO encourages market participants to review the updates to their Generator Resource Data Template (GRDT) to ensure that they match their expectations. Please select trade date Jan. 1, 2022, when retrieving the GRDT. The columns that were added with the VOMCR project are available in the GRDT, please see those identified as being associated with the VOMCR project on the Instruction tab.

Please note: The activation process places limitations on the ability to process Master File data changes; therefore, the ISO will honor a data freeze period. No Master File data change can be submitted effective from Dec. 8, 2021 through Dec. 22, 2021. Master File changes can resume after Variable Operations and Maintenance Master File data is loaded, subject to the normal 5 to 11 business day Master File change timeline.

For questions, please contact RDT@caiso.com.