Dec. 2, 2022
Information Only
DMM WEIM Resource Sufficiency Evaluation Enhancements Phase 2: October 2022 evaluation report, revised final proposal supplemental comments

The California ISO Department of Market Monitoring (DMM) has posted the Western Energy Imbalance Market (WEIM) Resource Sufficiency Evaluation Report for October 2022 to the Market Monitoring reports and presentations webpage. This report also covers test accuracy and performance during the September 2022 heatwave, including new discussions and analyses on the following topics:


  • The estimated impact of excluding lower priority exports from ISO’s tests, per the proposal from phase 2 of WEIM resource sufficiency evaluation enhancements.
  • Reliability demand response resources in the capacity test.
  • Variable energy resources in the capacity test.
  • Demand-response-based load adjustments in the resource sufficiency evaluation.


DMM has also posted supplemental comments on the ISO’s WEIM Resource Sufficiency Evaluation Enhancements Phase 2 Revised Final Proposal. These comments include additional analysis to help different balancing areas and stakeholders assess the implications of the Revised Final Proposal. For this analysis, DMM performed a back cast of what the potential costs and impacts of the energy assistance program would have been if provisions of the Revised Final Proposal had been in effect during the critical period from Sept. 5 to 8, 2022.


Information related to market monitoring is available on the Market Monitoring webpage.


Please contact Kyle Westendorf at or the Department of Market Monitoring at (916) 351-2174 or with any questions.

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