CMWG 9/20/21 - CIMView

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CMWG 9/20/21

Table of Contents

Executive Summary

Two new NPRRs were proposed; one to require non-dispatchable (wind/solar) resources behind generic transmission constraints to follow base points when the constraint is close to binding, and the other to allow ERCOT to move the location of Resource Nodes in the model when the point of interconnection changes.  Both seemed reasonable.

ERCOT presented data discussing how big a problem congestion could be if gas prices are very high (an Exelon request).  This raised some eyebrows and ERCOT will probably provide suggestions on how to deal with this in coming months.

ERCOT presented their proposed solution to the one day overlap of credit requirements for monthly and seasonal CRR auctions.  WMS needs to approve a calendar change for this to go into effect, but look for it in the next 2-3 months.

There was continued discussion on the possible change of shadow price caps to shadow price curves.  This has some powerful interests (anyone who likes volatility, so batteries and traders) lined up against it and it is very technical, so not many people fully understand it.  No real conclusion was reached, with ERCOT very mildly coming out against it.  It will get moved back to WMS for a vote.



  • Constraint Management in EEA3 – Freddy Garcia from ERCOT shared that the details of how ERCOT manages constraints in EEA3 are in the Shift Supervisor and Transmission desk procedures.
  • LCRA Model Improvement Suggestions – LCRA wants the far ahead CRR models to be better.  They identified two problems, but it seems unlikely that anything will gain traction.  If you have a trading desk you might look into taking these inaccuracies into consideration for your congestion trades.
  • CRR Auction Credit Enhancement – Currently most months have one day where both the monthly and the long term CRR auction credit is locked up.  ERCOT proposes to release the monthly credit one day early to fix this.  This will need a CRR calendar change approved at WMS.  It is a good idea.
  • New NPRR (no number) to better manage wind and solar behind GTCs – ERCOT would like to require wind and solar resources behind GTCs to follow base points.  It is a good idea.
  • OBDRR 026 (Shadow Price Curves) – No news, but this will go back to WMS.  If approved it would reduce congestion price effects caused by small rating exceedances.
  • Congestion when prices are at the cap – ERCOT presented data about how congestion might cause significant under generation issues if all gas resources offer at the cap.  This could conceivably be a problem if there is a serious cold event in December 2021.  This topic will be discussed further.
  • Revenue Neutrality (RENA) Update – There was a net RENA credit of $2.3M to the market for June 2021 due to an underselling of wind and solar on the Day Ahead on 6/13 and 6/14 2021.

Discussed Issues