Comments on phase 1B analysis presented during the April 1, 2022 stakeholder call

1. Please provide your organization's comments on the resource sufficiency evaluation load conformance impact analysis.

NV Energy appreciates the Resource Sufficiency analysis that CAISO has conducted on the load biasing impact and the comparison of uncertainty using the histogram and mosaic approaches. Additionally, NV Energy is supportive of utilizing analysis to determine where further Resource Sufficiency enhancements are needed.  

NV Energy provides the following questions and thoughts for consideration:  

In slide 3, NV Energy believes it would be helpful to see the total amount of bid in intertie capacity (System Resource), not including dynamics, from 2019 to 2022 to associate with the HASP and FMM bias graphs. We would like to understand if the increased need for load bias in HASP and FMM is related to the bid in intertie capacity.  

2. Please provide your organization's comments on the analysis for the flexible ramping uncertainty calculation in the WEIM.

Slide 23, “Performance comparison: M vs. H”, illustrates a comparison for each BAA for the Mosiac versus histogram approach calculation. It would be very beneficial if we could obtain this information on a monthly basis so that each BAA has an idea what the difference would be by month for a year.  The expectation is that the shoulder seasons would have a lot of improvement, meaning that each area should not have to carry as much capacity due to the shoulder seasons condition from the histogram calculation.  

Finally, we would be interested to know how easily the Mosiac model is configurable to the percentage of error for determining the final requirement. Currently, the 95% uncertainty component is a configurable value in the histogram and can be changed through BPM updates. Does the Mosiac have this same flexibility? 

3. Please provide your organization's input on the format of how the data in the RSE load conformance impact analysis is presented.

4. Please provide your organization's input on the format of how the data in the flexible ramping uncertainty calculation analysis is presented.

7. Please provide additional comments on the WEIM Resource Sufficiency Evaluation Enhancements Phase 1B analysis mentioned above.

1. Please provide your organization's comments on the resource sufficiency evaluation load conformance impact analysis.

PG&E supports the conclusions of the CAISO’s load conformance analysis and opposes proposals to incorporate load conformance into the RSE requirements

The main conclusion of CAISO’s analysis is that the use of load conformance does not enhance the CAISO BAA’s ability to pass the RSE tests.  The analysis found that, rather than benefiting the CAISO BAA, load conformance can be detrimental to the CAISO BAA’s ability to pass the RSE’s flexible ramping test (by reducing the amount of ramping capability that could otherwise be counted in the RSE).  Based on this analysis, PG&E believes there is no justification for proposals to add load conformance to the RSE requirements.  Both DMM and the MSC have also recommended that load conformance should not be incorporated in the RSE capacity test requirements.[1]   The relationship between load conformance and changes in different sources of supply was shown to be complex and highly variable, and PG&E agrees with CAISO’s warning of the “inherent difficulty and potential inaccuracies”[2] of attempting to derive a relationship that could be utilized in the RSE.  

The systematic use of load conformance by CAISO operators to gain additional ramping capability also highlights the importance of validating and implementing the planned improvements to the Flexible Ramping Product (FRP).  PG&E encourages the CAISO to prioritize successful implementation of the FRP improvements in the Fall of 2022.   

[1]

Motion to intervene and comments of the Department of Market Monitoring of the California Independent System Operator Corporation.  Docket ER22-1278.  April 1, 2022. Pg. 8 at http://www.caiso.com/Documents/Motion-to-Intervene-Comments-ER22-1278-WEIM-RSE-Enhancements-Apr-1-2022.pdf

Opinion on Energy Imbalance Market (EIM) Resource Sufficiency Evaluation Enhancements.  Members of the Market Surveillance Committee of the California ISO.  February 2, 2022.  Pg. 13 at http://www.caiso.com/Documents/MSCFinalOpiniononEIMResourceSufficiencyEvaluationEnhancements-Phase1.pdf

[2] “Load Conformance Impact on the Resource Sufficiency Evaluation.” Guillermo Bautista Alderete, Sheng Chen, Scott Lehnman.  CAISO Market Analysis and Forecasting.  Pg. 23 at http://www.caiso.com/InitiativeDocuments/Analysis-LoadConformanceImpactonResourceSufficiencyEvaluation.pdf

2. Please provide your organization's comments on the analysis for the flexible ramping uncertainty calculation in the WEIM.

3. Please provide your organization's input on the format of how the data in the RSE load conformance impact analysis is presented.

4. Please provide your organization's input on the format of how the data in the flexible ramping uncertainty calculation analysis is presented.

7. Please provide additional comments on the WEIM Resource Sufficiency Evaluation Enhancements Phase 1B analysis mentioned above.

1. Please provide your organization's comments on the resource sufficiency evaluation load conformance impact analysis.

Please see Powerex’s comments available at CAISO EIM RSE Enhancements Phase 1B Analysis Comments 

2. Please provide your organization's comments on the analysis for the flexible ramping uncertainty calculation in the WEIM.

Please see Powerex’s comments available at CAISO EIM RSE Enhancements Phase 1B Analysis Comments 

3. Please provide your organization's input on the format of how the data in the RSE load conformance impact analysis is presented.

Please see Powerex’s comments available at CAISO EIM RSE Enhancements Phase 1B Analysis Comments 

4. Please provide your organization's input on the format of how the data in the flexible ramping uncertainty calculation analysis is presented.

Please see Powerex’s comments available at CAISO EIM RSE Enhancements Phase 1B Analysis Comments 

7. Please provide additional comments on the WEIM Resource Sufficiency Evaluation Enhancements Phase 1B analysis mentioned above.

Please see Powerex’s comments available at CAISO EIM RSE Enhancements Phase 1B Analysis Comments 

1. Please provide your organization's comments on the resource sufficiency evaluation load conformance impact analysis.

Salt River Project Agricultural Improvement and Power District (SRP) appreciates the CAISO conducting Phase 1B of the WEIM Resource Sufficiency Evaluation Enhancements as requested by stakeholders.

The CAISO provided a summary of the Capacity and Flex Test input, which excludes the WEIM transfers. The data presented during the meeting only shows the supply side of equation related to these tests. The demand side of the test (the requirement) is dependent on the load forecast, variability, and uncertainty.

There is a divergence in utilization of load forecast during the RSE test and the expected load forecast, which includes load conformance. This may lead to passing the RSE when the forecast used is much lower, resulting in a lower RSE requirement.

SRP requests that the CAISO revisit the Capacity and Flex Test evaluation based on the load conformance used from the demand side perspective.

2. Please provide your organization's comments on the analysis for the flexible ramping uncertainty calculation in the WEIM.

SRP requests that the CAISO expand the analysis for the flexible ramping uncertainty calculation to include the demand side perspective.

3. Please provide your organization's input on the format of how the data in the RSE load conformance impact analysis is presented.

 No comments at this time.

4. Please provide your organization's input on the format of how the data in the flexible ramping uncertainty calculation analysis is presented.

 No comments at this time.

7. Please provide additional comments on the WEIM Resource Sufficiency Evaluation Enhancements Phase 1B analysis mentioned above.

SRP appreciates the CAISO’s efforts for Phase 1B and looks forward to further analysis and discussion.