14 Ancillary Services
Requirements
Figure 111 illustrates the IFM daily average ancillary service requirement for regulation up, regulation down, spinning and non-spinning. Figure 112 shows the IFM hourly average ancillary service requirement for regulation up and regulation down.
Figure 111: IFM (Day-Ahead) Ancillary Services Average Requirement
Figure 112: IFM (Day-Ahead) Hourly Average Regulation Requirement
Procurements
Figure 113 illustrates the IFM daily average procurement of regulation up, spinning and non-spinning ancillary services.
Figure 113: IFM (Day-Ahead) Upward Ancillary Services Procurement
Figure 114: IFM (Day-Ahead) Regulation Down Procurement
Figure 115 illustrates the real-time daily average procurement of upward ancillary services. It includes regulation up and regulation down procured in real-time unit commitment (RTUC), and spinning and non-spinning procured in RTUC. (Does not contain HASP like original metric catalog.)
Figure 115: Real-Time Upward Ancillary Services Procurement
Figure 116 illustrates the RTUC daily average procurement of regulation down.
Figure 116: Real-Time Upward Ancillary Services Procurement
The ISO procures 100 percent of its ancillary services requirements in the IFM (day-ahead) based on the IFM load forecast. Incremental procurements in the real-time market occurs under two scenarios. First, ancillary services requirements have changed in real-time market motivated by a change in the real-time load forecast. Second, if a unit which was awarded an ancillary service in IFM (day-ahead) is unable to provide that service in real-time. The market will automatically procure additional services to replace that service. Figure 117 displays the percentage of real-time procurement with respect to the IFM (day-ahead) procurement for all four types of ancillary services. The real-time procurement of regulation down and regulation up is actually the procurement in RTUC, while the real-time procurement of spinning and non-spinning is the sum of procurement in both RTUC and HASP. The percentage for each type of ancillary service is calculated as: (hourly average of real-time (RTUC and HASP) procurement in 15 minute intervals) / (hourly IFM (day-ahead) procurement).
Figure 117: Proportion of Real-Time Procurement as Percentage of Day-Ahead Requirement
IFM (Day-Ahead) Average Prices
Figure 118 and Figure 119 illustrate the IFM daily and hourly average price for regulation up, regulation down, spinning and non-spinning ancillary services. The average price for each type of ancillary services is calculated as: sum (non-self scheduled AS MW * ancillary services marginal price $/MW (ASMP)) / sum (non-self scheduled AS MW).
Figure 118: IFM (Day-Ahead) Ancillary Service Average Price
Figure 119: IFM (Day-Ahead) Hourly Average Ancillary Service Price
Figure 120 illustrates the real-time daily average price for ancillary services, including the average price for regulation up and regulation down procured in RTUC, and the average price for spinning and non-spinning procured in both RTUC and HASP. The average price for each type of ancillary services is calculated as: hourly average of [sum (non-self scheduled AS MW * ancillary services marginal price $/MW (ASMP)) / sum (non-self scheduled AS MW)] for each of the 15 minute intervals.
Figure 120: FMM (Real-Time) Ancillary Service Average Price
Average Regional Ancillary Service Shadow Prices
Figure 121 through Figure 124 display the IFM daily average regional ancillary service shadow prices (RASSPs) for regulation up, spinning, non-spinning and regulation down.
Figure 121: IFM (Day-Ahead) Regulation Up (RASSP)
Figure 122: IFM (Day-Ahead) Spinning (RASSP)
Figure 123: IFM (Day-Ahead) Non-Spinning (RASSP)
Figure 124: IFM (Day-Ahead) Regulation Down (RASSP)
