ERCOT Files Notice Of Protocol Violations Related To SCED Logic, A/S Postings
In a filing with the Texas PUC, the Electric Reliability Council of Texas, Inc. (ERCOT) notified the Commission of violations of certain posting requirements in 16 TAC § 25.505 as well as an inadvertent disclosure of certain generator interconnection information in violation of ERCOT Protocol Section 1.3.1. ERCOT also provided notice herein of a recently discovered inconsistency between logic used in Security Constrained Economic Dispatch (SCED) and ERCOT Protocol Section 188.8.131.52(4).
Posting of Ancillary Services Offer Information Following High-Price Events
16 TAC § 25.505(f) requires ERCOT to post certain market-related information on its website, either on a fixed schedule or when certain high-price events occur. If the Market Clearing Price for Energy (MCPE) or the Market Clearing Price for Capacity (MCPC) exceeds the "event trigger" during any interval, the rule requires ERCOT to post the portion of every Market Participant's price-quantity offer pairs for balancing energy service and each other Ancillary Service that is at or above the event trigger for that service and that interval seven days after the day for which the offer is submitted. The event trigger is a calculated value for each interval that is equal to 50 times the Houston Ship Channel natural gas price index for each operating day, expressed in dollars per megawatt-hour (MWh) or dollars per megawatt per hour (MW/h).
ERCOT said that, on June 6, 2017, as part of an internal review of ERCOT's adherence to Commission rules, ERCOT discovered that it had not been posting price-quantity offer pairs for Ancillary Services for intervals in which the MCPC exceeded the event trigger, as required by 16 TAC § 25.505(0(3)(B)(ii). After investigating the matter, ERCOT determined that it had ceased posting the required information as part of the implementation of the nodal market systems on December 1, 2010, and that this change occurred because the underlying posting requirement had inadvertently not been carried over from the Zonal Protocols to the Nodal Protocols. ERCOT determined that, between December 1, 2010 and June 7, 2017, there were approximately 108 days on which the Day-Ahead Market (DAM) MCPC was greater than 50 times the event trigger, and approximately 64 days on which the Supplemental Ancillary Services Market (SASM) MCPC was greater than 50 times the event trigger.
On July 26, 2017, ERCOT posted NPRR843, Short-Term System Adequacy and AS Offer Disclosure Reports Additions, to add the posting requirement in accordance with 16 TAC § 25.505(0(3)(B)(ii). NPRR843 was approved by the ERCOT Board of Directors at its December 12, 2017, meeting. The estimated time to implement NPRR843 is approximately four to six months following its approval.
Inconsistency between SCED logic and ERCOT Protocol 184.108.40.206(4).
ERCOT said that it recently discovered an inconsistency between the logic used in its systems for the creation of proxy energy offer curves for SCED and ERCOT Protocols section 220.127.116.11(4), which governs the creation of proxy energy offer curves for certain resources and scenarios. Protocols section 18.104.22.168(4)(a)-(d) requires that 1 MW be added or subtracted from certain values to create these proxy energy offer curves. However, this parameter has been programmed for SCED at 0.01 MW, rather than 1 MW, since December 1, 2010, the date of nodal market implementation.
This inconsistency impacted proxy energy offer curves for the small group of resources referenced in Protocols sections 22.214.171.124(4)(a)-(d), which are primarily intermittent renewable resources and dynamically scheduled resources that do not submit their own energy offer curves, ERCOT said. ERCOT has corrected this discrepancy in its systems, and the correct value of 1 MW has been used to create the applicable proxy energy offer curves for SCED since December 11, 2017. ERCOT issued a market notice on December 7, 2017, to inform market participants of this issue and of ERCOT's corrective action.
"This identified inconsistency may have affected SCED dispatch as well as prices to some extent; however, ERCOT is unable to determine with sufficient accuracy how prices may have been impacted due to the applicable parameter being set to a value of 0.01 MW. Any effort to recalculate new prices for operating days from December 1, 2010, to December 10, 2017, using the correct value of 1 MW to recreate the affected proxy energy offer curves would require significant assumptions about the operating condition of ERCOT System resources. This would necessarily call into question the accuracy of any recalculated prices," ERCOT said in its filing
Inadvertent Disclosure of Certain Generator Interconnection Study Information
Section 1.3.1 of the ERCOT Protocols prohibits ERCOT from disclosing information classified as "Protected Information" under the Protocols. Section 126.96.36.199(1)(l) provides that "information related to interconnection requests" is Protected Information until that status expires pursuant to section 1.3.3 following a request for a Full Interconnection Study by the project developer.
ERCOT said that, on August 16, 2017, an ERCOT employee accidentally sent an email containing one project developer's screening study report to another project developer. ERCOT staff immediately identified the error and notified the affected developer of the inadvertent disclosure. The recipients of the original email confirmed that they had permanently deleted the disclosed information. ERCOT has apologized to the affected parties for the inadvertent disclosure.
"ERCOT takes its responsibilities under the Commission's rules and the ERCOT Protocols seriously and appreciates the Commission's understanding in overseeing ERCOT's administration of these requirements. ERCOT is prepared to discuss these matters in further detail at the Commission's request," ERCOT said in its filing