CMWG 2/21/22 - CIMView

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CMWG 2/21/22

Table of Contents

Executive Summary

The CMWG meeting focused on two topics today.  The first topic, nodal prices for load resources, was basically a list of issues with giving nodal prices to controllable loads and discussion about those issues.  No consensus was reached on anything, but the discussion and any follow up with Sai is likely  to inform the NPRR that ERCOT will put forward in a few months.  The second issue was informational only; ERCOT has changed its methodology for computing the Panhandle GTC limit in a way that should increase transfer capability.



    • Nodal prices for Load Resources-  ERCOT (Sai Moorty) presented a white paper detailing issues and a tentative approach to nodal pricing for Controllable Load Resources (CLRs). The bulk of the time was spent figuring out how to give nodal prices to resources if they are co-located with generation or “normal” loads. Some other issues that were touched on but not resolved are:
      • What will eligibility be (size, controllable range?)
      • Does the procedure for a load resource declaring itself OUT need to change?  Should it be included in outage coordination?
      • Will this be for just resources connected at the transmission level, or at the distribution level as well?
      • Will CLRs be forced to ramp evenly over four minutes like other resources, or will they be allowed to ramp more quickly?
  • Panhandle GTC Limit- ERCOT (Jian Chen) gave a short presentation about changes to the way that ERCOT calculates the Panhandle GTC Limit.  First some background on Voltage Stability Analysis Tool (VSAT).  A VSAT study is performed by ramping up generation in one area (in this case the panhandle) and ramping down generation in another area (or ramping up load) until one of two things happens; 1, the study predicts a voltage collapse, or 2) the tool runs out of resources to ramp.  At that point the VSAT tool records the flow going across a determined interface and calls it (case 1) the stability limit or (case 2) the dispatch limit.  Obviously case 1 is a problem, whereas case 2 isn’t really an issue.  However, prior to December 2021, ERCOT would include the result of the VSAT study in the limit setting process whether it was the dispatch limit or the stability limit.  In December ERCOT started only including the stability limit in its limit setting process for the Day Ahead market. In March 2022 ERCOT will stop including the dispatch limit in the Real-Time market.  


Discussed Issues