1.
Please provide a summary of your organization’s comments on the Day-Ahead Sufficiency straw proposal:
The Public Advocates Office at the California Public Utilities Commission (Cal Advocates) is the state-appointed independent ratepayer advocate at the California Public Utilities Commission (CPUC). Our goal is to ensure that California ratepayers have affordable, safe, and reliable utility services while advancing the state’s environmental goals. Our efforts to protect ratepayers include energy, water, and communications regulation advocacy.
Cal Advocates recommends that the California Independent System Operator (CAISO) use this initiative to explore more cost-effective solutions for curing Resource Sufficiency Evaluation (RSE) shortfalls. Exceptional Dispatch Capacity Procurement Mechanism (CPM) designations should be a last resort solution for curing an RSE shortfall if other, more cost-effective solutions are not available.
7.
Additional comments:
An RSE shortfall occurs when insufficient energy is offered to the day-ahead market to meet the CAISO’s forecasted next-day needs in the CAISO Balancing Authority Area (BAA). The CAISO has considered a number of solutions, such as bid-insertion of Resource Adequacy (RA) resources and stand-in advisory assumptions.[1] The Straw Proposal also states that the CAISO “plans to use its existing Exceptional Dispatch authority to address any underlying reliability issues identified by the EDAM RSE.”[2] Exceptional Dispatch refers to either an out-of-market order to dispatch an RA resource within the day-ahead or real-time timeframes or a CPM designation of a non-RA resource.[3] Exceptional Dispatch CPMs would procure the greater of the Pmin of the designated resource or the volume needed to clear the shortfall.[4] The CPM would have a delivery term of no less than 30 days[5] and pay the CPM Soft Offer Cap of $7.34/kilowatt-month (kW-mo).[6] The CAISO is willing to consider alternatives due to prior stakeholder concerns that the cost of an Exceptional Dispatch CPM may be an inefficient solution for an RSE shortfall.[7]
The CAISO should consider more cost-effective alternatives to using an Exceptional Dispatch CPM to cure an RSE shortfall. A 30-day delivery term to cure what may be a single hour in a single day of the RSE is not a cost-effective solution. For example, a 20 megawatt (MW) shortfall in a single hour of the RSE when the locational marginal price (LMP) is $90/MWh has a value of $1,800. Curing the shortfall with a 30-day CPM designation would cost at least $146,800, not including any energy payments for actual dispatch.[8] Assuming a “Tier 2” failure and a maximum Mid-C or Palo Verde cost of $100/MWh,[9] the surcharge for failing to cure the RSE would be $6,000.[10] This surcharge estimate does not include the consequence of the CAISO balancing authority area (BAA) being evaluated individually, rather than as a pooled resource, at the real-time RSE due to an EDAM RSE failure.[11] The cost of curing an RSE shortfall should not be significantly higher than the cost of tolerating an RSE shortfall.
During the May 13 Working Group, Pacific Gas and Electric Company indicated that the Assistance Energy Transfer mechanism could apply as a potential solution for an RSE shortfall. The CAISO should explore this potential solution and other more cost-effective potential solutions in the course of this initiative. Exceptional Dispatch CPM should be a last resort measure to cure RSE shortfalls given the proportionally higher costs of a month-long CPM designation.
[1] CAISO, Day-Ahead Sufficiency: Straw Proposal, May 2024 (Straw Proposal) at 8. Available at: http://www.caiso.com/InitiativeDocuments/StrawProposal-Day-AheadSufficiency.pdf.
[2] Straw Proposal at 15.
[3] During the May 13 Working Group, CAISO staff indicated that either type of exceptional dispatch may be used to cure an RSE shortfall.
[4] CAISO Tariff 43A.2.5.2.1.
[5] CAISO Tariff 43A.3.6.
[6] The CPM Soft Offer Cap is currently $6.31/kW-mo but will increase to $7.34/kW-mo in June, 2024. CPM designations may be paid a lower or higher rate, but the Soft Offer Cap is the typical price paid to past CPM designations. CAISO Tariff 43A.4.1.1. See also CAISO, Resource Adequacy Working Group: Updated Discussion Paper & Draft Recommendation Plan, April 29, 2024 (RAMPD Draft Recommendation Plan) at 12, footnote 6. Available at: https://www.caiso.com/InitiativeDocuments/DiscussionPaper-ResourceAdequacyModeling-ProgramDesign-Apr29-2024.pdf.
[7] RAMPD Draft Recommendation Plan at 15-16.
[8] $7.34/kW-mo * 20,000 kW = $146,800. This assumes that the Pmin of the designated resource is below 20 MW.
[9] Administrative surcharges of RSE failures use a three-tier system that applies multipliers for higher severity. CAISO, Extended Day-Ahead Market Final Proposal, December 7, 2022 (EDAM Final Proposal) at 71. Available at: https://www.caiso.com/InitiativeDocuments/FinalProposal-ExtendedDay-AheadMarket.pdf.
[10] This example uses similar figures used in an example surcharge in the EDAM Final Proposal for convenience. EDAM Final Proposal at 73.
[11] Straw Proposal at 16.