2026 Variable operations and maintenance cost review

Started: May 20, 2026

Leads
Abhishek Hundiwale
Miheer Shah
Li He

Through this recurring triennial stakeholder process, the California Independent System Operator (ISO) will review the default variable operations and maintenance (VOM) adders and update these values as needed. The ISO will also introduce a new default value for the variable storage operations cost.

The VOM adder allows market participants to reflect their variable operations and maintenance costs in market bids. The ISO incorporates these adders into a resource’s proxy costs, which align with the three bid components used in the energy markets: default energy bids (DEBs), minimum load costs, and startup costs.

The variable storage operations cost allows market participants to reflect the variable cost of operating their battery storage resources in market bids. The ISO incorporates this adder into a resource’s storage default energy bid, and potentially into the negotiated DEB.

For an overarching view of where each initiative is in the development process, view the Policy Initiatives Timeline (updated weekly).

Status

Development Decision Implementation Completed/Closed
Aug 06, 2026 Paper posted
Aug 20, 2026 Meeting
Sep 03, 2026 Comments due
Oct 26, 2026* Board of Governors
Jul 07, 2026 Filed informational report

Activities

Web meeting


Presentation - 2026 Variable Operations and Maintenance Cost Review - Aug 20, 2026

Final Proposal - 2026 Variable Operations and Maintenance Cost Review (VOM)

Draft Tariff Language - 2026 Variable Operations and Maintenance Cost Review - Redlines

Submit comments Due: Sep 03, 05:00 pm

Web meeting


Straw Proposal - 2026 Variable Operations and Maintenance Cost Review - Jul 07, 2026

Presentation - 2026 Variable Operations and Maintenance Cost Review - Jul 09, 2026

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Web meeting


Issue Paper - 2026 Variable Operations and Maintenance Cost Review - May 29, 2026

Presentation - 2026 Variable Operations and Maintenance Cost Review - Jun 04, 2026

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