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6.1
6.2
6.3
6.4
6.4.1
6.4.2
6.4.3
6.4.4 Procedures for Closing the Day-Ahead Market
Bidding for DAM is closed at 1000 hours on the day preceding the Trading Day.
Consistent with Sections 7.6 and 7.7 of the CAISO tariff, the following actions are taken in the event of market disruptions. Actions taken vary depending on the cause of failure, expected time of resolution, and the status of the submitted Bids at the point of failure:
Ø Postpone the closure of the market. Postponement may be accommodated for a maximum of approximately two hours without impacting scheduling and Balancing Authority Area check out processes.
Ø Closing of the market and manual copying of Bids or Schedules from previous Trading Day.
Ø Closing of the market and using submitted Bids to the extent possible. Note, CAISO recommends that Scheduling Coordinators have seven days of Bids submitted to SIBR as a default in case Bids are not able to be submitted for a particular Trading Day.
Ø Cancellation of the market with import/export schedules being determined by submittal of an e-Tag. Established WECC scheduling rules apply when a failure of an e-Tag occurs.
Ø Suspension of all Virtual Bids at specific Eligible Pnodes or all Eligible Pnodes to allow all physical Bids to be cleared.
Ø If cancellation of the market or suspension of all Virtual Bids occurs, CAISO may issue operating orders for resources to be committed and dispatched to meet Demand. In this case, CAISO will set administrative prices to be used for settling Metered Supply and Demand as reflected in Section 7.7 of the CAISO Tariff.
Validation for Bids at Transmission Paths with Zero Rated OTC in Both Directions
As further discussed in the BPM for Market Instruments, the ISO market systems will validate all System Resource Bids, including Self-Schedules, for each Trading Hour to ensure that Bids submitted at open ties (i.e., interties where the transmission path OTC is rated to zero in both directions) are not considered in the ISO market processes, as required by Section 30.8 of the ISO Tariff.
7.
7.1 Differences from IFM
In general, the RTM applications are multi-interval optimization functions minimizing the cost of dispatching Imbalance Energy and procuring additional AS, when applicable, subject to resource and network constraints. In this respect, the RTM applications are not much different than the IFM application. The main differences are the following:
Ø The IFM application uses hourly time intervals, whereas the RTM applications use sub-hourly time intervals within their Time Horizon.
Ø The Time Horizon of the IFM application spans the next Trading Day, whereas the Time Horizon of the RTM applications is variable (due to submission timelines limiting the availability of real-time bids beyond the end of the next hour) and spans the current and next few Trading Hours at most. The RTM applications run at periodic intervals, every 5 or 15 minutes, with a Time Horizon that ends at or beyond the Time Horizon of the previous run. Results for time intervals past the first one in the Time Horizon are advisory since they are recalculated the next time the application runs.
Ø The IFM application uses Demand Bids to clear against Supply Bids, whereas the RTM applications use CAISO Forecast of CAISO Demand and final scheduled exports. Demand Bids and Virtual Bids are not accepted in the RTM.
Ø The RTM applications use the latest available information about resource availability and network status; in fact, the optimal Dispatch is initialized by the SE solution that is provided by the Energy Management System (EMS).
Ø The IFM application commits resources optimally for the next Trading Day using three-part Energy Bids. Almost all resources can be considered for optimal commitment, except for resources with extremely long Start-Up and/or Minimum Run Times, because the full cost impact of commitment decisions for these resources cannot be evaluated within the IFM Time Horizon. Similarly, the RTM applications that have Unit Commitment capabilities can commit resources optimally within their Time Horizon, however, because that Time Horizon is short (a few hours at most), only Fast-Start, Short-Start and Medium Start Units can be committed. Consequently, any Long-Start Units that are not scheduled in the IFM or RUC, are effectively not participating in the RTM.
Ø Unlike the IFM application, the RTM applications need to interface with the Automated Dispatch System (ADS) to communicate financially binding commitment and Dispatch Instructions, and with the CAS for confirmation of System Resource Schedules and Dispatch.
Ø The RTM applications provide more control to the CAISO Operator with the capability to adjust the Imbalance Energy requirements (via adjustments to the Load forecast), block commitment or Dispatch Instructions, or issue Exceptional Dispatches. This CAISO Operator input is necessary to address any unexpected system conditions that may occur in Real-Time.
Ø The RTM applications also provide the functionality to the CAISO Operator to switch the system or individual resources into a Contingency state under which Contingency Only Operating Reserves are dispatched optimally to address system contingencies. Contingency Only Operating Reserves are otherwise reserved and not dispatched by the RTM applications.
Ø The CAISO Operator may augment or supplant the Dispatch Instructions generated by the RTM application with Exceptional Dispatches if necessary to address system conditions that are beyond the modeling capability of the RTM applications.
Ø The ISO market systems will validate Bids at transmission paths with zero rated OTC in both directions. The details of this procedure are provided in the BPM for Market Instruments.