NOTICE DATE: August 19, 2015

NOTICE TYPE: W-B081915-01 General

SHORT DESCRIPTION: Monthly Responsive Reserve (RRS) requirements in July and August 2015

INTENDED AUDIENCE: All Market Participants

DAY AFFECTED: July 1, 2015 to August 17, 2015

LONG DESCRIPTION: The “ERCOT Methodologies for Determining Ancillary Services Requirements” document (effective January 1, 2015) requires that ERCOT publish a monthly RRS requirement for each four hour block for the upcoming year. ERCOT has identified that the Responsive Reserve (RRS) amounts procured for the month of July 2015 were different than the published monthly RRS amounts noted in the document “ERCOT Monthly Responsive Reserve Requirements beginning June 1, 2015” which is posted on the Market Information System (MIS) Secure Area.

In most hours (except Hour Ending (HE) 11 – 14), the RRS amounts procured were more than the monthly published RRS amounts for July 2015, as shown in Table 1 below.

Table 1
Projected Ancillary Services Requirements of RRS for July 2015		Amounts of RRS that were actually procured for July 2015		Prior Summer – 2014 (for comparison)
HE	Total RRS MW	HE	Total RRS MW	HE	Total RRS MW
23-02	2480	23-02	3002	23-02	2800
03-06	2696	03-06	3002	03-06	2800
07-10	2696	07-10	2808	07-10	2800
11-14	2702	11-14	2696	11-14	2800
15-18	2538	15-18	2696	15-18	2800
19-22	2538	19-22	2696	19-22	2800

Additionally, on August 17, 2015, ERCOT issued an Ancillary Service posting notice on the MIS Secure Area to inform Market Participants of the increase in HE 22 RRS requirements for the remainder of August beginning Operating Day August 18, 2015. ERCOT had identified that the RRS amount procured for HE 22 for Operating Days August 1 – 17 was lower than the monthly published RRS amount for that same hour, as shown on Table 2 below.

Table 2
Projected Ancillary Services Requirements of RRS August 2015 HE 22	Amounts of RRS that were actually procured for August 1-17 for HE 22
2538	2480

The Ancillary Service Plans for July and August 2015 which are posted daily in accordance with Protocol Section 4.2.1.1 did include the procured RRS requirements shown above. These procured RRS requirements were used in the clearing of the Day-Ahead Market (DAM) and the DAM Market Clearing Prices for Capacity (MCPCs) for RRS were consistent with the procured requirements.

ERCOT has analyzed reliability impacts of these procurements and determined that at no time was reliability of the ERCOT System affected. Based on the reserves procured and the overall system response to disturbance events during the impacted periods, ERCOT system performance met all reliability criteria.

ERCOT has conducted a root cause analysis and determined that the procured RRS requirements used for July 2015 and HE 22 for Operating Days August 1 – 17, 2015 were related to a failure in the manual process of communicating the monthly Ancillary Service Plan requirements to ERCOT staff in the Grid and Market Operations divisions. As a result of this communication, ERCOT procured a different quantity of RRS than the monthly published RRS amounts for July 2015 and HE 22 for Operating Days August 1 – 17, 2015.

ERCOT has submitted a system change request to allow pre-population of future months’ Ancillary Service Plan requirements. This system change will allow systems to import the monthly projected Ancillary Service Plan eliminating manual processes of communication and data entry. Additionally, this change will allow ERCOT to run a report of the Ancillary Service Plan in the system against the published monthly projected values on the MIS Secure Area for validation before implementation. In the interim, ERCOT has added additional manual verifications until the system changes are implemented. ERCOT will discuss this issue in more detail and answer questions from stakeholders at the August 27, 2015 Technical Advisory Committee (TAC) meeting during the ERCOT Operations, Planning, and IT Report.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at [log in to unmask].

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