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Proposed Revision Request Detail Help
PRR Life Cycle*******Final Decision**
PRR Details
PRR #
1678
Title Clarification on how storage resources are subject to ancillary service state of charge constraints and envelope constraints
Date Submitted 5/29/2026 3:45 PM
PRR Category B
Priority Normal
Owner Martin, Michael (CAISO)
Status Final Decision
Status End Date 8/18/2026 11:59 PM
Related BPM Market Operations
BPM Section 4.2.9 Ancillary Service Constraints for Storage Resources
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Existing Language

​See Attached

Proposed Language

​​See Attached​

Reason For Revision

This update details how State of Charge (SOC)​ constraints in Day Ahead ensure adequate SOC to cover all energy, ancillary services, and capacity products in each hour and how in Real Time SOC constraints ensure sufficient SOC to cover all energy, ancillary services, and flexible ramping awards in each interval​.

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BPM PRR Submitter

Martin, Michael (CAISO)
Modified BPM language proposed by the PBM Chnage Management Coordinator

Identification of the authorship of comments

NA
Action

Approve the BPM PRR as submitted

NA
Statement of apparent requirements of the BPM PRR

NA
Priority and rank for any BPM PRR requiring a CAISO system change

NA
Proposed effective date(s) of the BPM PRR

Other recommended actions

Approve as submitted
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Final Decision

Approve as modified
Stakeholder Comment

During the Change Management PRR meeting, the CAISO received a request to monitor the new SOC envelope constraints to ensure they do not cause excessive buyback of imbalance reserves. 
The MVQA team agreed and will update any such concerns in their MVQA Quarterly meetings.

Effective Date

8/4/2026
Action

Adopt the recommendation as modified

Version 2 was slightly modified with formula and example corrections.
Announcements
Please refer to the attached "BPM_SOC_constraints_in_EDAM_Final_v2.docx" which contains additions, clarifications, and formula updates.
Posted On - 7/9/2026 9:39 AM
Impact Analysis
PRR 1678 Impact Analysis Form.doc    
Notes:
Initial Comments
No Initial Comments available for this PRR.
Recommendation Comments
No Recommendation Comments available for this PRR.
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