The ISO is delaying posting of the draft final proposal until it completes further internal assessments on the technical feasibility of changing day-ahead market scheduling from hourly to 15-minute granularity. Concurrent with the stakeholder initiative, the ISO has been conducting performance testing on the day ahead market solve time under 15-minute scheduling granularity. The results to date have raised concerns on whether the system performance levels can meet the required market timelines. In Q4 2018, the ISO will continue to attempt to resolve the system performance issues and will also evaluate additional implementation approaches that require less computer processing resources. The time to perform additional technical studies does not change the planned
implementation date of fall 2020. In addition, there is no impact to the 2019 Draft Policy Initiatives Roadmap discussed with stakeholders on Sept. 18, 2018.
Information related to this initiative is available on the ISO website at http://www.caiso.com/informed/Pages/StakeholderProcesses/Day-AheadMarketEnhancements.aspx.
The ISO will brief the Board of Governors and EIM Governing Body at their next meetings to provide an update on the day-ahead market enhancements initiative. The decision on changing the day-ahead market scheduling from hourly to 15-minute granularity will be made in Q1 2019.
