Through this triennially recurring stakeholder process, the ISO will review the default variable operations and maintenance adders and, if necessary, update these default values.
| Proposal Development | Decision | Implementation | Completed/Closed |
|---|---|---|---|
|
Aug 23, 2023 Final proposal posted
Aug 23, 2023 Draft tariff language posted |
Nov 21, 2023 FERC approval (ER23-2956)
Sep 28, 2023 Tariff amendment (ER23-2956) Sep 20, 2023 Board of Governors approval |
Dec 1, 2023 Activation
Implementation milestones
Outcome statement: The California ISO received FERC approval for the tariff amendments associated with the Variable Operations and Maintenance Cost Review 2023 initiative. To implement these tariff amendments, the ISO updated the default variable operations and maintenance adders effective Dec. 1, 2023. The variable operations and maintenance (VOM) adder and major maintenance adder (MMA) currently in place allow market participants to include their VOM and major maintenance costs in their bids. The CAISO includes these adders in the resource’s “proxy costs”, which mirror the three parts of market participants’ bids into the energy markets: default energy bids (DEBs), minimum load costs, and startup costs. The VOM adder is included in DEBs under the variable cost-based methodology and in minimum load costs under the Proxy Cost option. MMAs are included in minimum load costs and startup costs under the Proxy Cost option. This implementation changed the structure of how operations and maintenance (O&M) costs are estimated for use in the CAISO markets. This implementation is composed of three scope items: • Scope 1: Defining the O&M cost components, including how to differentiate between fixed and variable O&M costs. • Scope 2: Redefining the Operations and Maintenance (O&M) adder components. • Scope 3: Allow market participants to bid in all of their variable maintenance costs through a new default maintenance adder in lieu of the current MMA. |
Completed |