Comments on 2023 and 2027 local capacity requirements technical study draft results

1. Please provide your organization’s overall comments on the 2023 and 2027 Local Capacity Requirements Technical Study Draft Results:

PG&E appreciates the opportunity to provide comments on the 2023 and 2027 Local Capacity Requirements (LCR) Technical Study Draft Results.  Below please find PG&E’s brief comments.

At the March 9, 2022, stakeholder meeting, CAISO shared that they plan to publish a white paper on the study methodology used to assess battery storage charging constraints in LCR studies.  PG&E applauds this effort and recommends that the CAISO publish the white paper no later than the draft LCR report, in order that stakeholders better understand the assessment in time for reviewing the draft report.

1. Please provide your organization’s overall comments on the 2023 and 2027 Local Capacity Requirements Technical Study Draft Results:

SDG&E appreciates the opportunity to provide comments on the 2023-2027 Local Capacity Requirements – Technical Study Draft Results. CAISO’s approach to the LCR this year was sound and in line with the approach from previous year. However, we would like CAISO to publish information used to derive the LCR results. Specifically, it is very important for stakeholders to get a hold of the following documentation:

1. The final LCR power flow case. CAISO has published this case before and we would like CAISO to do this more regularly.
2. The analysis and spreadsheets that were the basis of the Load Serving Capability graphs that account for storage constraints.

In both cases, it is important for relevant stakeholders to review and analyze the data such that potential pitfalls and solutions might be identified early. This will also provide for a more robust TPP that is more inclusive of creative ideas.

1. Please provide your organization’s overall comments on the 2023 and 2027 Local Capacity Requirements Technical Study Draft Results:

Vistra Corp. respectfully submits these comments on the CAISO’s 2023 and 2027 Local Capacity Technical Study Draft Report and Study Results (“Draft Reports”) posted on March 7, 2022 and discussed at a public stakeholder call on March 9, 2022.

Our focus continues to remain on increasing transparency and understanding of the study used to estimate the storage characteristics for local resource adequacy purposes. In addition, it has come to our attention that there may be some confusion about the status of projects that are under construction for work necessary to complete the interconnection or that have long-term contracts executed that are pending regulatory approval.

In these comments on the Draft Reports, we will focus on four areas of the 2023 & 2027 Draft LCR Study Results Greater Bay Area[1]:

• Power Plant Changes (slide 4)
• Approximate storage in GBA – South Bay – Moss Landing LCR subarea (slide 16)
• Approximate storage in GBA – Oakland LCR subarea
• Feedback to improve digestibility of estimated battery storage characteristics analysis

Power plant changes clarifications (slide 4)

• Please confirm what MW amount and source of the expected additions is for the “OCEI Energy Storage” MW addition? Specifically, Vistra asks the CAISO to confirm the source of the 43 MW value shown on slide 17 for market/net seller/battery generation that appears to assume that the 110 MW of jet-fuel combustion turbine units are retired in 2023 and an additional 43 MW is being modeled as replacement batteries.
• Please confirm which projects described in the power plant changes contributed to the generation increase from market/net seller/battery projects at South Bay – Moss Landing LCR sub-area from 2,165 MW in 2022 LCR study[2] to 2,977 shown on slide 13.
• Please confirm the above increased generation between 2022 and 2023 LCR studies, includes the two phases of the Moss Landing Battery Energy Storage Facility that have achieved commercial operations, where 400 MW of the increased 812 MW of generation in the South Bay – Moss Landing sub-area is being contributed by Dallas Energy Storage units 1-4.

Approximate storage in GBA – South Bay – Moss Landing LCR subarea (slide 16)

• Please confirm our understanding from your verbal response during the stakeholder call that the approximate storage size that can be added to this area from a charging restriction perspective for local resource adequacy purposes are values that include the existing storage resources modeled in the case.
• Specifically, please confirm that if there is 400 MW of 4-hour storage in operations in a sub-area and the 2023 1 for 1 max 4-hour storage MW value is 465 MW that this means only 65 MW of additional 4-hour storage can provide local resource adequacy capacity, without increasing the total Local Capacity Requirement.
• Please confirm the 400 MW of battery storage at the Moss Landing 500 kV substation that achieved commercial operations in 2021 were modeled in the 2023 and 2027 LCR study.
• Please confirm if there was any additional battery energy storage generation modeled in the LCR sub-area that would increase the amount of battery storage online modeled as existing in this LCR sub-area and if so, what the total amount of battery energy storage generation is in this LCR sub-area as modeled in this LCR study.
• Please confirm whether for purposes of estimating the 1 for 1 replacement max 4-hour storage value, whether the CAISO is making assumptions on whether the battery is charging, discharging, or idle in order to estimate the value.

Approximate storage in GBA – Oakland LCR subarea

• In 2022 and 2026 LCR study results the CAISO identified the Oakland sub-area had a 22 MW, 181 MWh, and 11 4-hour 1 for 1 replacement MW for 2022 and had a 37 MW, 276 MWh, and no limit to 4-hour battery for 1 for 1 replacement in 2026. Please provide updated estimate values for the Oakland sub-area for 2023 and 2027.
• Please clarify why the values described above are not in the draft results at this stage?

Feedback to improve digestibility of estimated battery storage characteristics analysis

Vistra recommends the CAISO consider updating the load and resources information describing the inputs to the LCR study for generation assumption be enhanced to give greater transparency on the battery storage generation being modeled. It would be helpful to separate non-battery generation and battery generation into two separate values in the market/net seller/battery row. Given our understanding the estimated battery storage characteristics include the battery storage modeled as well, it would be beneficial for the CAISO to denote the MW and MWh of existing storage modeled in the case. It would also be useful to denote the amount of 4-hour storage in MW that is modeled in the case. This will make it easier for stakeholders to interpret the estimated storage characteristic values being reported considering whether the modeled existing generation is included in these values or not.

[1] 2023 & 2027 Draft LCR Study Results Greater Bay Area, March 9, 2022, http://www.caiso.com/InitiativeDocuments/Presentation-Draft2023and2027LCRBayAreaLocalArea-Mar092022.pdf.

[2] 2022 Local Capacity Technical Study, Final Report and Study Results, April 30, 2021, Page 71, http://www.caiso.com/InitiativeDocuments/Final2022LocalCapacityTechnicalReport.pdf.