Comments on straw proposal

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

In 2021, the California Independent System Operator (CAISO or ISO) developed the Minimum State-of-Charge (MSOC) Requirement as part of the Summer 2021 Readiness Initiative, a reaction to the rolling outages that affected the grid during August 2020. The MSOC Requirement was adopted to address concerns about storage resources being unable to meet day-ahead (DA) discharge schedules in the real-time (RT) market because they were either not sufficiently charged or they were prematurely discharged in the RT market.

The adoption of this requirement was contentious and involved significant stakeholder engagement and negotiation at the highest levels of the ISO and the different parties involved in the aforementioned initiative. While the CAISO’s initial position was to apply the requirement in all days and for all storage resources with DA schedules, the proposal was eventually modified in response to stakeholder opposition. Use of the MSOC Requirement was restricted to resource adequacy (RA) resources on only the most constrained days and hours. In addition, the MSOC Requirement was adopted with a sunset clause, meaning that it would only be in place through Summer 2022 while committing the ISO and stakeholders to expeditiously collaborate and develop a successor mechanism to the MSOC Requirement. These changes to the original MSOC Requirement proposal convinced CESA to agree to its application as an emergency measure that would be timely replaced.

Since the MSOC Requirement was adopted, the ISO and stakeholders have concluded the Energy Storage Enhancements (ESE) initiative, the policy venue where the tools necessary to replace the MSOC Requirements were developed. Today, despite the fact that said policy was approved by the ISO’s Board of Governors over 5 months prior to summer 2023, the Straw Proposal notes that aspects of the replacement proposal will not be developed until the software release in fall 2023. Moreover, despite the fact that development of these features is now anticipated to be completed by the end of 2023, the Straw Proposal goes as far as to enable the MSOC Requirement to remain operational through September 30, 2024. This is deeply concerning to stakeholders that proactively engaged in good faith with the ISO through the Summer 2021 Readiness and ESE initiatives, dedicating time and resources to ensure the timely development of tools that would allow the CAISO to fulfill its promise and retire the MSOC Requirement by end-of-year 2022. In this context, CESA’s comments can be summarized as follows:

• CESA encourages the ISO to reprioritize their technology development work in order to ensure the timely substitution of the MSOC requirement.
  • CAISO operations already has ability to issue state-of-charge (SOC) exceptional dispatch (ED) as of September 2022 when the CAISO began issuing SOC ED to preserve state of charge going into critical hours.[1]
  • CAISO technology team should focus on improving its tools to more easily issue SOC ED separate from implementation of other elements approved as part of the ESE Initiative. Since the CAISO already has this authority there is no need to wait for ESE implementation, where if additional tool improvements are needed for operators to more easily issue SOC ED these are operational improvements that should be prioritized.
• If CAISO staff believes that the compensation components related to the SOC ED will be ready for Summer 2023, as stated in the Straw Proposal, the ISO should prioritize implementing the settlement components as well.
  • If the ISO’s Technology team is unable to fully implement the settlement components that will more fully make storage whole for its opportunity costs when it receives SOC ED by Summer 2023 but is able to develop a means to otherwise compensate storage resources being taken out of the RT market to reach and hold a SOC it should do so.  
• If, despite stakeholder opposition, ISO staff moves forward with extending the MSOC requirement, it should be for a single year (2023).
  • This aligns with the good faith efforts of stakeholders that have collaborated with the ISO since 2021 to ensure replacement tools and settlements for the MSOC Requirement.
  • Further delaying action on retiring the MSOC Requirement will impact storage policy development more broadly, significantly hindering the ISO’s efforts to integrate and take advantage of these resources.
  • If the ISO is successful in extending its authority to issue MSOC through 2023 or 2024, such authority should be paired with a compensation mechanism to compensate storage assets affected by the extension of the MSOC Requirement.
    • CESA does not object to this being done ex-post as a form of resettlement, if approved by Federal Energy Regulatory Commission. 

[1] CAISO Summer Market Performance Report for September 2022, Page 150

2. Please provide comments on the WEIM Governing Body classification.

CESA offers no comments at this time.

3. Please provide any additional input not included above related to the straw proposal.

CESA requests the ISO provides additional information on how MSOC and SOC ED have been used by operations in 2021 and 2022. There is insufficient information for market participants to understand the ISO’s stated need to extend the MSOC without this information. It is unclear how MSOC enforcement by CAISO operators is impacting storage operations even from the information provided in the market performance reports or on OASIS reports. As such, CESA urges the ISO to supplement this information gap by providing stakeholders data on the hours and magnitude of capacity under MSOC as well as the hours and magnitude of capacity under SOC ED, from May 2021 until November 2022. 

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

Please see DMM comments in PDF attachment at the end of this comment template. 

DMM comments will also be posted in the following location, under the heading "2023 comments on policy initiatives": http://www.caiso.com/market/Pages/MarketMonitoring/MarketMonitoringReportsPresentations/Default.aspx#comments

2. Please provide comments on the WEIM Governing Body classification.

Please see DMM comments in PDF attachment at the end of this comment template. 

DMM comments will also be posted in the following location, under the heading "2023 comments on policy initiatives": http://www.caiso.com/market/Pages/MarketMonitoring/MarketMonitoringReportsPresentations/Default.aspx#comments

3. Please provide any additional input not included above related to the straw proposal.

Please see DMM comments in PDF attachment at the end of this comment template. 

DMM comments will also be posted in the following location, under the heading "2023 comments on policy initiatives": http://www.caiso.com/market/Pages/MarketMonitoring/MarketMonitoringReportsPresentations/Default.aspx#comments

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

The Public Advocates Office at the California Public Utilities Commission (Cal Advocates) supports the California Independent System Operator’s (CAISO) proposal to temporarily extend the use of the Minimum State of Charge (MSOC) constraint until the new Exceptional Dispatch (ED) tools developed in the Energy Storage Enhancements Initiative have been implemented.[1]  Cal Advocates agrees with the CAISO that it is reasonable to continue using all available tools to maintain reliability in summer 2023 given the delay in implementing the new tools.  The MSOC is only used in critical hours during stressed grid conditions, and operators have the ability to suspend enforcement or overside the constraint with manual ED instructions if deemed necessary.  The temporary extension will provide CAISO operators continued access to the tools that were successfully deployed in the summers of 2021 and 2022 to maintain system reliability.    

However, to ensure that the new tools are implemented as expeditiously as possible, Cal Advocates recommends that the MSOC extension be limited to one year instead of two years as proposed by the CAISO.[2]

Moreover, Cal Advocates strongly supports the development of robust market-based mechanisms for optimally scheduling storage resources to maintain sufficient state-of-charge (SOC) to meet CAISO system reliability needs in the most cost-efficient manner.  Cal Advocates supports the development of market enhancements for SOC in the CAISO Price Formation Enhancements Initiative.

[1] CAISO Minimum Stat of Charge Extension Straw Proposal, February 2, 2023 (Straw Proposal) at 8-9.  Available at: http://www.caiso.com/InitiativeDocuments/StrawProposal-Minimum-state-of-charge-extension.pdf

[2] Straw Proposal at 6, 9.

2. Please provide comments on the WEIM Governing Body classification.

Cal Advocates has no comments at this time.

3. Please provide any additional input not included above related to the straw proposal.

 Cal Advocates has no additional comments at this time.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

EDF-R appreciates the opportunity to provide these comments on the CAISO’s Minimum State of Charge Extension Straw Proposal discussed with stakeholders on February 9, 2023. The CAISO is proposing to extend the use of the Minimum State of Charge (MSOC) constraint through summer 2023 and no later than September 2024. EDF-R does not support the extension.

The CAISO proposed the MSOC for battery storage resources during the 2021 Market Enhancements initiative. Since that first proposal EDF-R has held the opinion that this requirement is not supported by empirical data, and it has the potential for penalizing battery storage resources for response in the real-time market.  EDF-R does not support the extension of the MSOC for the following reasons:

1. The MSOC is unduly discriminatory to battery storage resources, applying restrictions to storage when traditional resources cannot meet demand
2. The CAISO already has in place the authority to issue storage resources exceptional dispatches to hold SOC, which obliviates the need for MSOC and is more transparent to market participants than the MSOC
3. CAISO has not demonstrated that the MSOC improves reliability, the September 2022 heat wave has showed that the MSOC may actually be contributing to reliability risks during the exact system conditions the tool was supposed to help maintain reliability

CAISO, the joint agencies, and stakeholders worked through the 2021 Market Enhancements initiative with the understanding that the proposed changes were required to address urgent reliability and supply concerns after the August 2020 blackouts. EDF-R supported the MSOC only with the caveat that CAISO incorporate a specific sunset date for the MSOC. The CAISO asked for and received reluctant stakeholder support on a serious austerity measure. EDF-R requests the CAISO meet its commitment to sunset the MSCO tool this year (2023).

2. Please provide comments on the WEIM Governing Body classification.

3. Please provide any additional input not included above related to the straw proposal.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

Middle River Power LLC (“MRP”) offers these brief comments on the CAISO’s February 2, 2023 Minimum State of Charge (“MSOC”) constraint Extension Straw Proposal.

Given the controversial nature of the MSOC constraint when it was implemented, given the CAISO’s original commitment to sunset the MSOC constraint after Summer 2022 (a commitment intended to help temper the controversy), and given the CAISO’s acknowledgement and the Vistra representative’s acknowledgement that the CAISO has already used Exceptional Dispatch to hold state of charge,[1] MRP respectfully urges the CAISO to sunset the MSOC constraint as originally proposed and accelerate its efforts to implement the counterfactual settlement and any other software modifications that may be required.   

MRP appreciates the opportunity to submit these comments. 

[1] On the February 9, 2023 call, Vistra’s Cathleen Colbert reported that the CAISO has used Exceptional Dispatch to hold state of charge on some Vistra storage resources – something the CAISO acknowledged on Slide 8 of the CAISO’s presentation for that call. 

2. Please provide comments on the WEIM Governing Body classification.

MRP supports the proposed classification.

3. Please provide any additional input not included above related to the straw proposal.

MRP has no further comments.  

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

PG&E appreciates the CAISO’s efforts preparing the Minimum State of Charge (MSOC) Extension proposal. PG&E’s opinions can be summarized as follows:

1. Extension of the MSOC is warranted if the CAISO requires this automated tool to ensure system reliability until the full implementation and testing of future software upgrades
2. The CAISO should offer more details as far as which energy storage enhancements (e.g. exceptional dispatch tools for resources to hold SOC) are currently available to operators

Extension of the MSOC is warranted until the full implementation and testing of the software upgrades

PG&E understands that the compensation (Settlements) mechanism for NGRs who were issued instructions to hold SOC is a software challenge that will take significant time to develop, validate and vet through market simulations. Thus, PG&E agrees with the CAISO that there is value in extending the MSOC if needed for reliability purposes, at least until the future Energy Storage Enhancement (ESE) software upgrades are fully implemented and tested.

The CAISO should offer more details as far as which energy storage enhancements (e.g. exceptional dispatch tools to hold SOC) are currently available to operators

PG&E agrees with both the CAISO and the broader stakeholder community that this extension would not be necessary if the changes from the ESE initiative were implemented, specifically the exceptional dispatch tools for non-generator resources (NGRs) to hold SOC. During the February 9^th stakeholder call, new information was presented by participants (e.g. Vistra, GDS Associates) which suggests that the exceptional dispatch ability of operators is multi-faceted, and that some functionality to issue instructions to NGRs to maintain SOC may already exist. PG&E requests that the CAISO formally respond to these claims and explain which (if any) tools operators already have at their disposal to deliver such instructions.

2. Please provide comments on the WEIM Governing Body classification.

3. Please provide any additional input not included above related to the straw proposal.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

REV Renewables (REV) opposes CAISO’s Straw Proposal to extend the Minimum State of Charge (MSOC) tool until September 30, 2024. As discussed in the Straw Proposal, in approving the MSOC, the CAISO committed to ensuring this was a temporary tool in place for no more than two years and would expire in 2022. Stakeholders worked diligently with CAISO in the Energy Storage Enhancements (ESE) initiative to develop a replacement for SOC, and the final proposal with new exceptional dispatch tools was approved by the CAISO Board of Governors and WEIM Governing Body in December 2022. Yet, CAISO notes that technology team currently anticipates that development of the compensation components of the policy would be implemented prior to summer 2023, but the remaining aspects of this policy will not be developed until the software release in fall 2023. While REV understands that software development and release is time-consuming, REV respectfully requests that CAISO keep its commitment to stakeholders and prioritize the new exceptional dispatch SOC tools in order to retire the MSOC as promised.

If CAISO is truly unable to fast track the new ESE tools, REV offers the following comments to further justify and limit the use of MSOC:

• CAISO should provide more data to justify why the existing exceptional dispatch tool to charge/hold a certain number of MWs (which CAISO can and does use for storage) is insufficient to support reliability and the MSOC tool specifically is necessary;
• CAISO should extend the use of the recently approved compensation for exceptional dispatch SOC mechanism to MSOC to make storage resources whole for the reliability service provided;
• If CAISO does extend the MSOC tool, CAISO should commit to no more than one additional year;
• CAISO should provide a clear and accelerated timeline by which the ESE solutions will be implemented, including the exceptional dispatch tools and the day-ahead default energy bid modification. Storage is a fast growing portion of the CAISO resource portfolio and it is critical to have these solutions in place to improve reliability and market efficiency.

2. Please provide comments on the WEIM Governing Body classification.

REV has no comments at this time.

3. Please provide any additional input not included above related to the straw proposal.

REV has no further comments at this time.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

SEIA appreciates the opportunity to comment on the CAISO proposal to extend the use of the temporary Minimum State of Charge (MSOC) requirement through summer 2024. SEIA understands the primary motivation for extending the MSOC is to provide system operators with a tool to manage battery resource state of charge under specific conditions when needed for reliability while CAISO works on implementation of the more robust exceptional dispatch tool developed under the Energy Storage Enhancements (ESE). SEIA appreciates this concern but asks that CAISO provide more specific justification for extending the MSOC when the exceptional dispatch tool is already available to system operators and has been applied to battery storage resources in the past.

SEIA believes it is crucial that battery storage resources are adequately compensated for following dispatch or operator instruction. Compensating resources for the lost opportunity costs incurred by holding state of charge, like the pricing methodology developed under the ESE, incentivizes resources to follow operator instruction and forgo higher real-time prices with the understanding that the resource will be made whole to lost revenues. This ensures the resource can provide energy for reliability economically. The MSOC, however, does not compensate resources for maintaining state of charge. The MSOC precludes certain battery storage resources from capitalizing on higher real-time prices that are signaling a reliability need and does not make the resource whole for lost revenues. SEIA appreciates that the exceptional dispatch compensation methodology will likely not be implemented in time for summer 2023 but asks that CAISO consider the potential for a resettlement for battery storage resources subject to exceptional dispatch prior to implementation.

2. Please provide comments on the WEIM Governing Body classification.

No comment.

3. Please provide any additional input not included above related to the straw proposal.

No comment.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

see attached

2. Please provide comments on the WEIM Governing Body classification.

3. Please provide any additional input not included above related to the straw proposal.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

During the multiple times Minimum State of Charge (“MSOC”) constraint has been used, it has been clear to Vistra that the use of MSOC does not achieve the CAISO’s goal to rationally reserve state of charge going into the critical need hours. In September 2022, the CAISO reports show that it enforced MSOC on nine days.[1] In its August 2002 report, the CAISO indicated that while a process gap led to CAISO operations not enforcing the MSOC in August 2022 that if the process gap had not occurred it would have been enforced on two days.[2] In 2021, the CAISO reported that the MSOC was enforced on three days.[3]

Vistra’s experience over the last two years suggests that MSOC has not resulted in the actual state of charge being preserved early enough to produce a rational way to manage state of charge.  We believe this is occurring because the real-time market optimization window that does not look out farther than 75 minutes in the future. In practice, operators issuing a hold state of charge exceptional dispatch (“hold ED”) appear to effectively preserve the state of charge during the middle of the day in advance of expected tight conditions in the evening net peak.

CAISO Summer Market Performance Report for September 2022 identified CAISO operators issued exceptional dispatches to “preserve state of charge for the peak hours”.[4] Figure 148 shows the use of exceptional dispatches to charge or preserve the state of charge on September 6, 7, and 8.[5]

As a storage owner and operator, we received hold EDs during September 2022 and found them the key to successful operations. Even on days with MSOC enforced we believe that CAISO will need to issue hold EDs earlier in the day to achieve the desired outcome of preserving the state of charge for the net peak hours. Before CAISO operations started issuing hold EDs, Vistra notified CAISO real-time operations that there were MSOCs enforced later in the day and they were dispatching storage sub-optimally to deplete the state of charge sooner than those hours. The real-time market window cannot ensure that the SOC required in the hours with MSOC limits are preserved sooner than one hour in advance. In contrast, an ED to hold SOC can ensure that the market does not drive charges during hours bordering under generation risks. After CAISO operations began issuing the EDs, we observed the state of charge begin to be used in a much more efficient way to better support net peak needs.

Without the hold ED the market can only issue charge instructions for the MSOC hour within one hour during an hour nearing shortage conditions, instead of earlier in the day during hours where the grid is less stressed. This observed performance appears to undermine reliability rather than to improve it.

We believe the real-time default energy bid (DEB) for energy storage fails to adequately reflect prevailing opportunity cost of the state of charge being used sooner than optimal. This suppressed DEB relative to other offers makes storage look more economic and mutes the signal to preserve its use for later hours. The DEB not sufficiently capturing real-time opportunity costs drives the need to use hold EDs to maintain state of charge.  Storage operator’s ability to bid to manage the state of charge is impeded during these periods since it is not allowed to bid above the $1,000/MWh based on its opportunity cost. The ability to manage state of charge faces even greater challenges when mitigated at levels well below real-time prices since the real-time default energy bid is based on day-ahead prices. These bidding limitations put storage at an operational disadvantage compared to other resources such as imports or transfers because it cannot request an energy reference level adjustment to reflect the opportunity cost of its use. Instead, it is seen as incorrectly more economic because its opportunity cost is not accurately being valued under mitigation or cost verified bids.

If CAISO is going to request a year extension, Vistra encourages CAISO to include in the changes reforms that allow us to make the MSOC workable in practice.  We believe changes to the DEB would be the most important near term complementary change.  We would like to share with the CAISO staff specifics about our experience with the MSOC to support why the change in the default energy bid, and the ability to request reference level adjustments based on opportunity cost above $1,000/MWh, will limit the unintended consequences of extending the MSOC.

[1] Summer Market Performance Report for September 2022, California ISO, Page 152, http://www.caiso.com/Documents/SummerMarketPerformanceReportforSeptember2022.pdf.

[2] Summer Market Performance Report for August 2022, California ISO, Page 83, http://www.caiso.com/Documents/SummerMarketPerformanceReportforAugust2022.pdf.

[3] Summer Market Performance Report for July 2021, California ISO, Page 108, http://www.caiso.com/Documents/SummerMarketPerformanceReportforJuly2021.pdf.

[4] Summer Market Performance Report for September 2022 at Page 150.

[5] Summer Market Performance Report for September 2022 at Page 151.

2. Please provide comments on the WEIM Governing Body classification.

WEIM Governing Body should have joint authority over this initiative because enforcing MSOC limits on batteries internal to California changes the real-time market dynamics in a way that can drive greater need for WEIM transfers to California to support California reliability due to limit the availability of internal generation during net peak hours.

3. Please provide any additional input not included above related to the straw proposal.

None at this time.

1. Please provide a summary of your organization’s general comments on the straw proposal and presentation for this initiative.

WPTF appreciates the opportunity to provide these comments on the CAISO’s Minimum State of Charge Extension Straw Proposal discussed with stakeholders on February 9, 2023. Through this effort the CAISO is proposing to extend the use of the Minimum State of Charge (MSOC) constraint through summer 2023 and no later than September 2024. While this may seem like a relatively straightforward effort – extend the existing Tariff provisions – it’s important to take this time and not only evaluate if the MSOC has been working as intended, but also consider the original discussions and agreements that took place when getting the MSOC to final approval.

WPTF is strongly opposed to extending the MSOC for the following three reasons and respectfully requests that the CAISO drop this initiative and retire the MSOC prior to Summer 2023 as originally scheduled.

1. MSOC was a temporary solution and is no longer needed as its replacement is already in place
2. MSOC may not function as intended and increase reliability risk during stressed system conditions
3. Storage has demonstrated an ability to charge and discharge consistent with real-time prices and grid need in all circumstances except when prices exceed $1,000/MWh. A better solution than an MSOC extension would be to allow storage to adjust their reference levels and thus bids when prices routinely exceed $1,000/MWh in a day. 

2. Please provide comments on the WEIM Governing Body classification.

3. Please provide any additional input not included above related to the straw proposal.

First, the MSOC was a temporary solution and is no longer needed as its replacement is already in place. When the CAISO first introduced the concept of the MSOC it was a highly contentious policy element. In the end, the CAISO was able to get the policy across the finish line by coming to an agreement with stakeholders that it will only be in place for two years while the CAISO works on a more permanent solution. During the stakeholder call the CAISO noted that the MSOC replacement is the ability to exceptionally dispatch storage resources to hold a state of charge and apply appropriate settlement treatment.

It is WPTF’s understanding that the CAISO operators now have the authority to issue exceptional dispatch instructions to storage resources to hold a certain state of charge – which is the MSOC replacement functionality. This was done during the September 2022 heat wave events.[1] First, WPTF would like the CAISO to confirm that operators today have the authority to issue exceptional dispatch instructions to storage resources to hold a certain state of charge. Given our understanding of current operator authority, WPTF sees absolutely no need to keep the MSOC in place given that its replacement is already being used by operators. While we understand that maybe what the CAISO was trying to explain during the stakeholder call is the settlement aspect of the MSOC replacement has yet to be filed at FERC, this is still not a reason to extend the MSOC. The CAISO can file the settlement element at FERC and implement before summer 2023, or in the event it’s not filed and approved prior to summer of 2023, simply settle any such EDs retroactively once it is approved and implemented. The key here is the ability for operators to exceptionally dispatch storage resources to hold a state of charge is the MSOC replacement, and the CAISO already has the authority to issue such EDs. In other words, the MSOC replacement is already effective so it would be redundant to then also extend the MSOC.

Second, the MSOC is not functioning as intended and is increasing reliability risk during stressed system conditions. The original idea of the MSOC was to provide operators with the ability, under certain system conditions, to ensure storage resources in real-time will have sufficient state-of-charge to meet their day-ahead schedules during critical hours. However, experience during the September 2022 heat wave has shown that the MSOC is not entirely effective in ensuring storage resources have sufficient SOC but may actually be contributing to reliability risks during the exact system conditions the tool was supposed to help maintain reliability.

The tool may not function as intended because the real-time lookout horizon is not long enough and by the time it sees the need to charge a storage resource to meet its day-ahead schedule, there isn’t enough time. For example, a resource may need to be at 80% SOC by HE 18 in real-time to support its day-ahead schedule. If operators enforce the MSOC, the real-time market may not “see” the MSOC constraint until there is 1-2 hours before HE18. Thus, if the storage resource is only partially charged and needs more than 1-2 hours to charge for it to get back to 80% SOC, there is no way the market is able to achieve that outcome. Similarly, it could end up with the entire fleet of storage resources unable to support their day-ahead schedules during critical peak hours, increasing reliability risk. During stressed system conditions its not uncommon to have higher energy market prices during hours leading up to the net load peak hours; energy prices may be high enough to discharge storage resources based on their offers. If the market ends up discharging storage resources in the hours leading up to the critical hours, it may end up with its entire fleet of storage resources needing to charge for several hours so they can support their day-ahead schedules when the MSOC is activated. However, as noted previously, the market may not “see” the MSOC early enough and thus end up with the entire fleet of storage resources unable to support their day-ahead schedules during critical hours.

To further improve the ability of the fleet of storage resources to support their day-ahead schedules during critical hours, the CAISO could consider allowing storage to submit reference level adjustments to update default energy bids and associated cost-based bids based on opportunity costs in that hour relative to the need to hold the state of charge for the future critical hours.

WPTF requests the CAISO provided more transparency into its historical use of MSOC and any hold ED on the days that MSOC were enforced. The CAISO should make available on its website for each month and hour whether MSOC was enforced, total number and capacity of storage assets online during that hour, total number and capacity of the storage assets providing RA, number and capacity of storage that received MSOC limits, number and capacity of storage resources that received charge exceptional dispatches, number and capacity of storage that received hold state of charge exceptional dispatches.

Third, storage has demonstrated an ability to charge and discharge consistent with real-time prices and grid need in all circumstances except when prices exceed $1,000/MWh. A better solution than an MSOC extension would be to allow storage to adjust their reference levels and thus bids when prices routinely exceed $1,000/MWh in a day. This was discussed in the CAISO stakeholder initiative catalog and described as an implementation issue; however, WPTF believes it would be more appropruate to change or clarify storage bid cap rules via a BPM change.

[1] Summer Market Performance Report for September 2022, California ISO, Pages 150-151, http://www.caiso.com/Documents/SummerMarketPerformanceReportforSeptember2022.pdf.