The California ISO, under its existing tariff authority in section 29.34(l)(5), will be suspending the net-load uncertainty adder from the capacity test within the Western Energy Imbalance Market (WEIM) resource sufficiency evaluation on the new effective date of Feb. 15, 2022. The ISO may issue further notices on a potential revised expected effective date, should testing on the implementation deem a revised date necessary.
Net-load uncertainty was added to the resource sufficiency evaluation’s capacity test’s requirement as part of the Market Enhancements for 2021 Summer Readiness initiative. While the addition of uncertainty had stakeholder support, concerns were raised regarding the existing methodology for calculating uncertainty; these concerns remain unresolved. With broad stakeholder support as detailed in the comments received in the WEIM Resource Sufficiency Evaluation Enhancements Phase 1 initiative, the ISO is moving under its existing authority to suspend this provision from the capacity test. The ISO will look to reconsider net-load
uncertainty within the capacity test in a future phase of the WEIM Resource Sufficiency Evaluation Enhancements initiative.