The ERCOT Wholesale Market Subcommittee (WMS) met on September 11 to discuss key operational updates, market revisions, and transmission elements. The meeting focused on proposed changes for 2025, congestion revenue rights (CRR) auction challenges, and load interconnection reports, among other topics. Discussions were framed around improving transparency, market design, and system performance, with a strong emphasis on collaboration with ERCOT staff and stakeholders.
Technical Advisory Committee (TAC) Update
TAC updates primarily focused on improvements to the stakeholder process, which has been a point of concern. A workshop scheduled for September 5 was canceled and will now be the first topic discussed at the upcoming TAC meeting on September 19. The first two hours of this meeting will focus solely on improving the stakeholder process. Additionally, the WMS report was well received, with commendation from TAC Chair Caitlin Smith on the collaboration with the Independent Market Monitor (IMM) on the state of the market report.
Proposed Changes to Ancillary Service Methodology for 2025
ERCOT staff presented proposed changes to the Ancillary Service (AS) methodology for 2025. Key changes include a shift from net load ramping to using forecasted net load error for regulation service, and adjustments to the generation to be dispatched (GTBD) application to incorporate net load forecast error. Specific updates to ERCOT’s methodology include removing the 90th percentile minimum for sunset hours and adjusting the frequency recovery portion of historical load to the 70th percentile. Additionally, non-spin service will now use a 4-hour net load forecast error for low peak hours. The updated methodology is expected to result in new minimum reserve requirements, with changes to the minimum RSPFR limit increasing from 1,185 MW to 1,365 MW for 2025. Concerns about potential regulation shortfalls during winter mornings were raised, but general support was expressed for the proposed changes. The methodology was endorsed and will be presented at TAC for further review.
Congestion Revenue Rights Auction Mitigation
ERCOT staff discussed challenges with long-term CRR auctions, especially those spanning three years. Recent performance issues have caused significant delays, with one auction taking 363 hours to converge. Proposed solutions include setting limits per time of use (TOU) to ensure timely auction solutions. Other potential changes discussed include lowering per-account holder limits, increasing minimum bid prices, and modifying capacity percentages for long-term auctions. Stakeholders expressed concern over the potential impact these changes could have on congestion hedging strategies and urged ERCOT to provide more transparency and feedback.
Large Load Interconnection Report
ERCOT reported continued growth in both standalone and co-located large load projects. The total queue capacity increased by 4,439 MW over the past month, with most projects slated for in-service dates by 2028. While there was a slight decrease in planning studies approved, a total of 5,496 MW has been approved to energize. Stakeholders raised concerns about transparency in reporting and the potential for double-counting loads. There was also a request for clearer timelines for projects expected to come online. ERCOT acknowledged the need for more detailed reporting and transparency moving forward.
NPRR1235 Dispatchable Reliability Reserve Service
The group discussed NPRR1235, which relates to the introduction of Dispatchable Reliability Reserve Service (DRRS) as an ancillary service. There was no consensus reached on adding Energy Storage Resources (ESRs) to this service, and further discussions are expected later in the year. ERCOT committed to reviewing the issue and potentially moving forward with filing an NPRR.
NPRR1229, CMP Payment Policy
NPRR1229, related to payment policy for constraint management plans (CMPs) affecting generators, was discussed in detail. ERCOT staff and stakeholders raised policy concerns, noting that the issue may need to be escalated to TAC or the PUC for resolution. There was no specific incident prompting the proposal, but there is a need to clarify what actions should be taken if a unit trips offline during a CMP.
Other NPRRs and Updates
Several other NPRRs were discussed, including NPRR1238 related to voluntary registration of loads with curtailable capabilities, and NPRR1241 regarding firm fuel supply services. NPRR1238, while important, was seen as being aligned with real-time co-optimization efforts and may be set aside for now. NPRR1241, dealing with hourly standby fees for firm fuel service, will require further discussion and refinement before moving forward. NPRR1230 will be handled by CMWG, and further input is awaited from ERCOT staff.
Demand Side Working Group (DSWG) Update
The DSWG provided updates on ADER and various NPRRs. A particular focus was placed on the 4CP adjustment, with two potential solutions being discussed: increasing transparency through daily reports or removing WSL from certain calculations. Discussions about the impact of WSL on pricing and load data will continue in future meetings.
