PDCWG Meeting - NPRR315

September 28, 2011
09:00 AM - 05:00 PM
ERCOT Austin
8000 Metropolis (Building E), Suite 100
Austin, TX 78744
RM 206B
Teleconference: 888-894-0587
Meeting number: 652 842 853
Meeting password: PDCWG123!!!



9:00 am

ERCOT Antitrust Guidelines For Members of Committees, Sub Committees & Working Groups

  • Antitrust Admonition v3.17.09: ERCOT strictly prohibits Market Participants and their employees who are participating in ERCOT activities from using their participation in ERCOT activities as a forum for engaging in practices or communications that violate the antitrust laws. The ERCOT Board has approved guidelines for members of ERCOT Committees, Subcommittees and Working Groups to be reviewed and followed by each Market Participant attending ERCOT meetings. If you have not received a copy of these Guidelines, copies are available at the Client Relations desk. Please remember your ongoing obligation to comply with all applicable laws, including the antitrust laws.
  • Introduction of meeting participants
  • Agenda Review

Sydney Niemeyer









9:05 am

Review of NPRR315, Revision of Responsive Reserve Measure to High Emergency Limit (formerly Revision of Responsive Reserve Measure to Net Dependable Capability)

  • Summary of TAC Discussion:
  • On 9/1/11, ERCOT Staff reiterated their concerns related to the use of HEL for calculating RRS; stated that using HEL could create a reliability concern due to the difference in HEL and HSL; that if HEL is used, ERCOT would need to require extensive testing of all Resource HELs to verify for accuracy before implementing; and requested that NPRR315 be rejected.  Some participants clarified that the HEL is only used for the calculation of RRS and that units would still be deployed to their HSL.  TAC requested that ROS/PDCWG continue to review NPRR315, including providing a reason for the use of the 20% to calculate RRS provided from a Generation Resource; and that ERCOT study the proposed solution.
  • Comments from ROS:
  • At its September 15, 2011, ROS considered Nodal Protocol Revision Request (NPRR) 315.  After discussion, ROS voted to request that PRS table NPRR315 to allow further review by the Performance Compliance Disturbance Working Group (PDCWG).  All Market Segments were present for the vote.





  • TAC request: Provide reason for use of 20% to calculate RRS
  • Intent of NPRR what benefit or relief does this provide?
  • ERCOT concerns (Review)

o   HEL is not sustainable.

o   RRS calculations based on HEL may not have ability to meet NERC Contingency Reserve requirement.

o   RRS is frequency responsive reserve.

o   Using HEL may lead to undeliverable RRS.

o   Using HEL may result in RRS awarded to fewer resources

    • Ramp limit?

o   Previous emergency events have shown that HSL is appropriate

o   No evidence to support use of HEL.

  • What impact does using HEL vs HSL have

o   Real Time system changes, proxy curves, EOCs

o   COP validation

o   Day Ahead procurement changes/differences between DA & RT

o   CRR - ?

o   RUC - ?

o   DRUC - ?

o   Keeps dispatch off of ducts

o   Manually adjustable HASL can fix?

  • Are there entities that set the HEL equal to the HSL?

o   What is their impact?

  • Is HEL an achievable value?

o   If not what is the point of listing it?  How is it used

  • If HEL is allowed

o   Is testing required over and above the HSL values?






12:00 pm




1:00 pm

Compile answers to morning questions.  Develop report/comments to NPRR which outlines the issue, summarizes the reliability and market concerns, proposed solutions to reliability and market concerns.  Recommendation(s) of open meeting attendees. 



5:00 pm



Scheduled pdcwg Meetings

Key Documents

Sep 21, 2011 - doc - 102.5 KB

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