Comments on Hybrid Resource Draft Final Proposal

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

AWEA-California appreciates CAISO’s continued efforts to implement rules for hybrid resource participation and to provide different options for resources to structure their participation in the CAISO market. AWEA-California also appreciates that CAISO is moving forward expeditiously with improvements to the Co-Located resource participation model and that CAISO recognizes that there will be a need to continuously improve and adjust participation options for Co-Located and Hybrid resources. Thus, AWEA-California appreciates that CAISO has already committed to opening up another stakeholder initiative on Hybrid Resources in late 2021 to consider improvements and adjustments for both market participation options based on actual operation experience with these models.

CAISO and market participants will gain additional experience with Hybrid and Co-Located Resources in the coming months. There will be substantial benefits to sharing that experience and relevant information on a regular and timely basis. Starting in late 2020, CAISO should establish a monthly stakeholder meeting where market participants can provide information on their experiences and the challenges they have encountered and where CAISO can share its operational experience with hybrid resources. This type of monthly forum will help better position stakeholders, market participants and CAISO for the next Hybrid Resources stakeholder initiative in 2021. While this type of monthly information sharing forum is not standard practice for CAISO stakeholder engagement, given the importance of hybrid resources and the increased reliance on them in the coming years, this type of forum is warranted and would provide significant benefits to stakeholders and to CAISO.

With respect to the Draft Final Proposal for Hybrid Resource participation, AWEA-California is concerned that the combination of tools and methods for Hybrid Resources to interact with the market are highly complex. In particular, the use of outage cards may result in the stranding of available capacity at times when it could be beneficial to the market and system operations. AWEA-California encourages the CAISO to explore a tool other than outage cards to communicate expected range of hybrid resource availability in the day-ahead timeframe to help address this concern. Additionally, the use of outage cards will inappropriately negatively impact hybrid resources RA contributions, by reducing their UCAP. AWEA-California also encourages CAISO to work to resolve issues with Hybrid Resources and provision of regulation. These issues are discussed in answers to CAISO’s specific questions regarding the Draft Final Proposal.

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

AWEA-California is concerned that the use of outage cards may cause a number of issues and encourages the CAISO to reconsider the use of outage cards for Hybrid Resources. CAISO should explore alternative structures for hybrid resources to communicate their expected range of availability to CAISO on a day-ahead basis. As discussed more under AWEA-California’s response to Question #9, the use of outage cards for Hybrid resources is likely to negatively affect a Hybrid Resource’s RA value (namely its UCAP value) even though that resource’s RA value has already been reduced by the CPUC in calculating its Qualifying Capacity (QC). CAISO should avoid double penalizing hybrid resources for their lack of grid charging and this can be achieved by not relying on outage cards for Hybrid Resources.

The use of outage cards may unnecessarily restrict CAISO’s ability to rely on resources that are available in real-time, simply because they were not expected to be available based on day-ahead expectations and, thus, an outage card was submitted. This could be particularly problematic in emergency conditions, such as those that have occurred this month, when CAISO requires additional capacity. For instance, assume that, based on day-ahead forecasts, a Hybrid Resource expects its solar output to be no more than 100 MW during hour-ending 18 and thus submits an outage card to CAISO for capacity above 100 MW for that hour. However, in real-time, the solar resource is actually capable of producing 115 MW. If CAISO is in need of additional capacity during that hour, will CAISO know that the additional 15 MW of capacity is available from this solar resource and be able to utilize it?  The use of an outage card could create confusion that could lead to that resource not being able to be called upon for the incremental 15 MW, even if the CAISO has the actual solar capability in the form of the High-Sustainable Limit? Even if the system isn’t in an emergency situation, there should be an ability for this incremental 15 MW to be utilized if it beneficial to the grid. Thus, CAISO should evaluate a different communication tool for Hybrid Resources that is less likely to have these downsides.

For these reasons, and the RA concerns further discussed in Question #9, it appears that the use of outage cards may not be the ideal mechanism for Hybrid Resource Scheduling Coordinators to communicate expected Hybrid operational characteristics to the CAISO on a day-ahead basis. CAISO should consider implementing a new tool/communication tool that is more flexible than outage cards for use by Hybrid Resources. A more flexible communication tool would allow Hybrid Resources to communicate their expected operational range to CAISO on a day-ahead basis but would not unduly restrict them from operating outside of that range in real-time, providing reliability benefits and supporting the state’s goals for maximizing clean energy output.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

While AWEA-California is disappointed that CAISO is not improving the aggregate capability constraint to allow it to address ITC-charging restrictions, we recognize that CAISO believes these restrictions should be addressed through use of the Hybrid participation model and/or through economic bidding. AWEA-California appreciates that CAISO has indicated it will work with resources that cannot recover ITC-related costs from economically bidding into the market and anticipates that, in those instances, CAISO would work with the resource to explore some sort of aggregate capability constraint that would prevent grid-charging. 

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

AWEA-California greatly appreciates that CAISO has moved this Co-Located model improvement forward as expeditiously as it has. AWEA-California supports the proposal to allow Co-Located storage resources to deviate from dispatch to absorb excess renewable energy production. This improvement supports the state’s clean energy goals and AWEA-California appreciates that CAISO is moving forward quickly, with implementation scheduled for February 2021.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

As currently structured, the Hybrid Resources Draft Final Proposal will double penalize hybrid resources that do not wish to charge from the grid (in order to address ITC-charging restrictions) and would inappropriately limit the RA contributions to hybrid resources. Under the CPUC’s new QC methodology for hybrid resources that have ITC-charging restrictions, the renewable resource component’s QC is “de-rated” to account for the energy to charge the storage device. But as these resources also submit outage cards to CAISO, as currently proposed in the Draft Final Proposal, to communicate periods when the resource’s full output is not available and to prevent grid-charging, those outages will negatively impact the Hybrid Resource’s UCAP value. This is likely to result in another “de-rate” to Hybrid Resource’s RA value for the same operational restrictions. This is inappropriate and will artificially lower Hybrid Resource’s ability to contribute to the CAISO’s RA needs. CAISO should commit to ensuring this outcome is avoided and, as suggested elsewhere in these comments, use of a tool other than outage cards may help address this concern.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

AWEA-California appreciates that various stakeholders have brought forward their operational experience with hybrid resource participation to better inform other stakeholders about Hybrid an Co-Located resource participation. For instance, during the August stakeholder meetings, the Western Power Trading Forum (WPTF) explained that it had learned that hybrid resources would be severely restricted in receiving regulation awards based on a resource’s actual operational experience. This type of information sharing is beneficial to all market participants and AWEA-California encourages CAISO to consider an ongoing information sharing forum for Hybrid Resources over the coming months. This would allow hybrid resource Scheduling Coordinators and the CAISO to share operational experience and discuss potential improvements as more experience with hybrid resources is gained. AWEA-California urges CAISO to implement a monthly stakeholder call on Hybrid and Co-Located resource experience. The calls could commence in late 2020 and continue until the next Hybrid Resources initiative kicks off in late 2021.

Additionally, with respect to regulation awards, AWEA-California understands that CAISO may not be able to implement a solution to this identified issue prior to finalizing this stakeholder initiative for Board and FERC consideration. AWEA-California encourages CAISO to explore potential solutions and be ready to provide those potential solutions at the beginning of the next Hybrid Resources initiative in 2021, if not earlier.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

CalCCA appreciates the CAISO’s continued efforts to develop and refine market participation rules for hybrid resources and co-located resources. CalCCA’s comments focus primarily on the following issues.

1. Improving CAISO’s ability to optimize storage resources in the real time market:

CalCCA encourages CAISO to redouble its efforts to identify a better real time solution than the proposed minimum charge requirement. If it is not feasible to have a longer RTD time horizon than 65 minutes, CAISO should consider one or two reruns of the DAM prior to the beginning of each day and/or prior to the start of the daily storage charging hours.

2. Addressing downward VER deviations for co-located resources:

CalCCA continues to support CAISO allowing for downward VER deviations to be offset by reduced co-located resource charging deviations to avoid unnecessary grid charging. These deviations are necessary to allow storage resources with Investment Tax Credit (ITC) charging restrictions to choose the co-located configuration without risking inadvertent grid charging that can occur because of VER forecast error between the time storage resource bids must be submitted and energy is produced by the VER in real-time.

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

CalCCA is concerned that CAISO’s “optimization” of hybrid resources in the day-ahead market will be suboptimal, since it will be limited by the collective educated guesses of the hybrid resource operators about which hours will be preferred for charging and discharging of the storage component. Because hybrid operators could face the risk of infeasible day-ahead discharge schedules, we anticipate that these operators may choose to essentially self-schedule day-ahead a potentially significant portion of their combined hybrid resource capability. Unfortunately, this result may be an unavoidable aspect of the hybrid structure, but it points up the importance of making the co-located configuration as attractive as possible for resource owners. This is because the co-located configuration allows the CAISO to optimize each component of the co-located resource. We therefore urge the CAISO to reconsider its decision to not allow co-located storage resources to deviate from dispatch instructions when necessary to avoid inadvertent grid charging as further described in our response to Question 6.

CalCCA reiterates its comments on the RA Enhancements 5^th Revised Straw Proposal that CalCCA continues to be concerned about CAISO’s inability to optimize storage resources in the real-time market. The examples in Tables 14 and 15 of the RA Enhancements 5th Revised Straw Proposal illustrate the inefficiencies that will be created by this failure. For example, Table 15 shows that 50 MWh of available bid-in storage energy that otherwise would have cleared the RTM for HE18 is blocked by the 80 MWh minimum charge requirement and then none of the energy that was being preserved by the minimum charge requirement clears any of the subsequent intervals. This outcome will result in increased costs for consumers and increased risks for generators. The minimum charge requirement is a poor substitute for a better optimized real-time market solution with a longer time horizon to avoid the suboptimal result illustrated by Table 15.

CalCCA encourages CAISO to redouble its efforts to identify a better real time solution. If it is not feasible to have a longer RTD time horizon than 65 minutes, CAISO should consider one or two reruns of the DAM prior to the beginning of each day and/or prior to the start of the daily storage charging hours. The results of the DAM rerun(s) would have the benefit of much better-informed load and VER forecasts, additional information regarding generation and transmission outages, and more up-to-date storage state of charge information from the RTM. The DAM rerun could then be used to set minimum charge requirements that would be better aligned with RTM conditions for the remainder of the RTM intervals.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

CalCCA supports CAISO’s forecasting and dynamic limits proposals, as described in the draft final proposal

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

CalCCA supports CAISO’s proposal to enhance the aggregate capability constraint for co-located resources, as described in the draft final proposal.

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

While the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation described in the draft final proposal is a step in the right direction, it falls short. CAISO also should allow for downward VER deviations to be offset by reduced co-located resource charging deviations. These deviations are necessary to allow storage resources with Investment Tax Credit (ITC) charging restrictions to choose the co-located configuration without risking inadvertent grid charging that can occur because of VER forecast error between the time storage resource bids must be submitted and energy is produced by the VER in real-time. Figure 1 attached illustrates how these forecast error deviations would occur if CAISO does not allow co-located storage resources to deviate from their Dispatch Instructions under the circumstance in which the co-located VER deviates in the downward direction below the level of charging Dispatch Instruction for the co-located storage resource. The inadvertent grid charging that would result either will reduce the ITC benefits of the storage resource or will motivate resource operators to schedule their co-located resources in such a manner that CAISO will not have as much storage capacity available to it or will have more upward uninstructed imbalance energy from VER resources. Neither outcome is desirable.

CalCCA urges CAISO to allow the co-located storage resource to deviate from its charging schedule as necessary to avoid inadvertent grid charging due to real-time market VER forecast error. We understand that there may be a concern that this will result in the co-located storage resource having a reduced state of charge for subsequent use. We believe that this concern does not acknowledge the likelihood that either i. some other storage resource that is providing regulation up will provide the energy needed to charge the co-located storage resource whose companion VER is producing less than forecast, or ii. a thermal regulating resource may provide the imbalance energy, resulting in increased GHG emissions. Either result is not desirable. Figure 2 attached illustrates that rather than charging from the grid, the unexpected downward deviation in solar output is offset with reduced storage charging in that interval. The result is that for the co-located resource shown, the state of charge is lower than was expected by the 5-minute forecast, however another storage regulation resource likely will have retained its state of charge to offset this deviation. Note that by allowing the storage resource to deviate from its charge schedule when solar output is lower than expected, the actual output at the point of interconnection (POI) for the co-located resource is closer to the expected schedule if downward deviations are allowed, and the amount of VER production and storage resource charging from the co-located resource is the same with or without the downward deviation rule.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

CalCCA supports CAISO’s metering proposal, as described in the draft final proposal.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

CalCCA supports eligibility of hybrid and co-located resources for providing ancillary services.

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

During the August 10 stakeholder call, some stakeholders noted that CAISO’s proposal to use outage cards for hybrid resources could result in these resources being double penalized by potential UCAP reductions and by CPUC counting rules. The CPUC’s hybrid counting rules already discount the VER portion in the ELCC calculations and for expected storage charging. Further reductions to UCAP resulting from the use of outage cards would unfairly penalize these resources. Additional work is needed to ensure CAISO’s treatment of hybrid resources is not inconsistent with the CPUC counting rules.

CalCCA also seeks clarification that hybrid resources that submit bids for the full range of their resource adequacy obligations will not need to submit outage cards for the amount of capacity reflected in their bids. For example, a hybrid resource with a solar forecast to produce at a consistent output of 80 MW for several hours that plans to use a 50 MW portion of that output to charge the on-site battery if prices are below a given level, but is willing to deliver the full 80 to the grid if prices are above a given level, would not need to submit an outage card for 50 MW for the VER component. Similarly, for the storage component, if there is available stored energy and the resource bids reflect a willingness to discharge the full 50 MW associated with the storage component if prices exceed a given level, no outage card would be needed even if the resource operator plans to charge the storage resource.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

CESA supports and appreciates the ISO’s efforts to provide clarity and certainty regarding the market integration of hybrid and co-located resources. With this initiative, the ISO has positioned itself as a nation-wide leader on the subject. In general terms, CESA is supportive of this initiative’s intent; nevertheless, CESA is also concerned with the following elements of this initiative:

• The interaction of this initiative’s proposal to use outage cards to signal unavailability as it relates to the CPUC’s Resource Adequacy (RA) Program, as well as the ISO’s RA Enhancements Initiative.
• The modeling of VER-based hybrids with marginal amounts of energy storage and no intention to use grid charging.
• The determination of treating all co-located storage deviations from dispatch as UIE.
• The prohibition to co-located storage devices from deviating from dispatch when providing ancillary services.
• The potential limitation of regulation and ancillary service awards to hybrid resources.

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

In Section 4.1, the ISO states that on-site charging is a feature that many hybrid resources have asked for, but comments that this feature inherently reduces the availability of a hybrid resource for dispatch from the ISO market.[1] Further, the ISO notes that this reduction in dispatch capability must be captured in outage cards, submitted to the ISO through the ISO’s outage management system.[2] As explained further below, CESA requests that the ISO reevaluate the use of outage cards to account for the charging behavior of hybrid resources as it could lead to a double penalization based on the CPUC QC rules for hybrid resources.

[1] Proposal, at 8.

[2] Ibid.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

CESA is supportive, with caveats, of the ISO’s forecasting and dynamic limits proposal. CESA appreciates the ISO’s work to make forecasting tools available to hybrid resources. Furthermore, CESA agrees with the need for a tool that allows the ISO to use forecasts in order to ensure dispatch instructions sent to hybrid assets are actually feasible. Nevertheless, CESA believes one core modification must be made within this section.

In Section 4.3, the ISO states that most, but not all, hybrid resources will be modeled as a non-generator resource (NGR).[1] The ISO goes on to state that modelling and interconnection requirements will be tailored to each interconnection request, using a gas-powered hybrid as an example for a hybrid resource modeled as a generator instead of an NGR.[2] This same logic should be applied for VERs that add marginal amounts of energy storage to normalize or stabilize their output. In these cases. the ISO must model these resources as hybrids under the VER model, assigning them eligible intermittent resource (EIR) or participating intermittent resource (PIR) status. This modification is necessary and useful, as it will address a potential use case where VER-based hybrids that do not seek to charge from the grid can still participate and provide grid value.

[1] Proposal, at 11.

[2] Ibid.

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

CESA offers no comments at this time.  

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

CESA supports the spirit of this modification, as it allows further operational flexibility and it could potentially maximize the utilization of renewable energy within the ISO’s footprint. While supportive of the inclusion of this topic in the Draft Final Proposal, CESA is concerned with the ISO’s intent to consider any deviation as uninstructed imbalance energy (UIE), thus attributing it flexible ramping charges. This treatment is contrary to the one currently applied to standalone VERs. Currently, variations from dispatch from VER resources are not considered UIE. In this sense, the ISO’s proposal here is inconsistent with the net impact of co-located storage deviation. If a solar or wind standalone asset deviates from its forecasted dispatch, this is not considered UIE because the usage of renewable energy has been maximized. In the case encompassed by this proposal, the net effect is the same: the storage modifies its behavior downward in order to maximize grid usage of renewable assets. In this sense, CESA considers it would be both counterproductive and contradictory to consider storage deviations as UIE without modifying the treatment of the same behavior for standalone VERs. Thus, CESA urges the ISO to revise this proposal and either exempt co-located storage deviations from UIE treatment until the settlement process modifications are done to ensure a netted settlement can be applied, or treat standalone VER deviations in the same manner, as UIE.  

Moreover, CESA is concerned with the ISO’s blanket prohibition of utilizing this feature when the co-located storage asset is providing ancillary services. It is clear that some ancillary services could be affected if a storage resource opts to use this feature; nevertheless, it is not reasonable to completely prohibit this case, as different types of ancillary services would be more or less compatible with this feature depending on the situation. As such, CESA urges the ISO to revisit this assumption.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

CESA offers no comments at this time.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

CESA urges the ISO to address issues related to the provision of regulation by hybrid resources. During the stakeholder call on August 10, stakeholders mentioned some hybrid assets have been unable to provide regulation due to the visibility of VER generation relative to the potential of on-site storage. In effect, the storage component of hybrid resources may be limited in its full ability to provide ancillary services due to the VER component in the market. CESA requests that these issues be addressed before all co-located and hybrid resources are eligible to provide ancillary services.

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

CESA opposes the use of outage cards within this section of the proposal as it could lead to a double penalization for hybrid resources. In the Draft Final Proposal, the ISO considers two ways to capture the variability of hybrid resources. First, to account for the charging behavior of the energy storage component and the hours of low or zero solar generation, hybrid resources will submit outage cards in the day-ahead (DA) market. Second, to account for the intra-hour variance of solar generation, hybrid resources will be subject to a dynamic limit tool in the real-time (RT) market, derived in part from the VER’s high sustainable limit. CESA agrees with the latter; nevertheless, the use of outage cards requires further consideration in the context of the CPUC’s hybrid resource QC methodology and the changes to the RA structure contemplated within the ISO’s RA Enhancements Initiative.

As currently drafted, the Draft Final Proposal expects to capture part of the variability of hybrid resources via outage cards. This approach could potentially hinder the UCAP value of hybrid resources due to the use of outage cards during hours where the on-site generation is set to charge on-site storage. The ISO should reevaluate this method due to its potential to derate hybrid capacity twice for the same charging behavior. This use of outage cards, as well as its potential UCAP consequences, may be duplicative of the California Public Utilities Commission’s (CPUC) determination on the qualifying capacity (QC) of hybrid assets, since charging considerations have already been incorporated in the CPUC’s methodology via a derate of the effective load carrying capability (ELCC) of the on-site VERs. Moreover, that UCAP evaluation hours are not know by asset owners and operators a priori, thus increasing said risk. As such, the method contained in the Draft Final Proposal should be reconsidered as it does represent an unfair discount valuation of the reliability contributions of hybrid resources.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

CESA offers no additional comments at this time.

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

Please see comments attached below.

2. Provide a summary of your organization's comments on this proposal:

Please see comments attached below.

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

Please see comments attached below.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

Please see comments attached below.

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

Please see comments attached below.

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

Please see comments attached below.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

Please see comments attached below.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

Please see comments attached below.

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

Please see comments attached below.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

Please see comments attached below.

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

Support this intiative and the commitment to conduct a future follow-on initiative using operational experience

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

support

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

support

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

support

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

support

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

support

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

support

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

support

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

Final proposal needs statement of principle that hybrids will be treated as single resource throughout the Interconnection, market operations, settlement and market monitoring processes.

Final proposal should state what changes, if any, should be made to WDAT and/or CAISO tariffs to allow market participation of hybrids where one element is retail load.

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

EDF-Renewables (EDF-R), the Large-scale Solar Association (LSA), and the Solar Energy Industries Association (SEIA) (collectively, the Developers) appreciate the opportunity to comment on the CAISO’s latest proposals in this initiative.  The Developers support many Proposal elements (though with some caveats), oppose others, and recommend more information and clarification for several.  Our feedback on the main issues is summarized below and explained further in the remainder of this document. 

(Note:  For brevity, these acronyms are used to reference the two mixed-fuel project configurations throughout this document: (1) CLR = Co-located Resource; (2) HR = Hybrid Resource.)

• Support with caveats:

1. CAISO adoption of our earlier CLR storage flexibility proposal, though we have concerns with some proposed restrictions, most notably the “blanket” prohibition against CLRs providing Ancillary Services while using the proposed storage flexibility.
2. The overall Aggregate Capability Constraint (ACC) framework, where we recommend that the CAISO provide additional information and clarification.

• Oppose (strongly):  The proposed HR availability/outage reporting framework, which is unworkable and unnecessarily complex, inconsistent with both CPUC policy and other CAISO proposals in this and other initiatives, and unduly discriminatory against resources in the HR configuration compared to the same technologies in stand-alone and CLR configurations.  This is the most problematic element of the Proposal and requires considerable revision to overcome our strong opposition.

• More information and explanation needed

1. High Sustainable Limit:  The White Paper is a reasonable start, but several questions we have asked multiple times are still not addressed.  The Developers recommend postponing this requirement until a more thorough discussion can be held.
2. HRs providing Regulation:  Stakeholders need further understanding about possible restrictions on the HR Regulation range and how any restrictions can be removed quickly.
3. HR 24 x 7 Must-Offer Obligation (MOO) proposal:  This concept seems unworkable where some of the NQC is from the VER component. 
4. Metering requirements:  Stakeholders need additional information on how DC meters would be configured, and clarification about any additional meters needed for storage charging energy.

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

(Note:  The comment categories in this template do not match the categories in either the Proposal or the stakeholder meeting presentation.  In particular, it’s not clear whether the proposed HR availability-reporting framework, through the Outage Card submittals and Dynamic Limit (DL) Tool, are “market interaction” proposals (to be covered here) or “forecasting and dynamic limits” proposals (Question #4 below).  Our comments on that framework are included under Question #4.)

24 x 7 HR Must-Offer Obligation:  This obligation would be problematic where some of the HR RA value comes from the VER component. 

For example, assume a 100 MW HR project with 100 MW of solar capacity and 50 MW of four-hour storage.  In a given month, the storage NQC would be 50 MW, and the solar capacity would add something more (call it “X,” since the solar profiles for the new CPUC-adopted methodology have not yet been released), so the total HR NQC would be (50+X) MW.

Solar availability would be zero at night, so there’s no way that the HR can submit a bid above 50 MW.  (If an Outage Card would be required in this situation, and that submittal would count against the resource UCAP value, please see arguments below about why this would be discriminatory (and double-count outages for UCAP purposes) compared to treatment of stand-alone VERs, which do not submit Outage Cards for fuel unavailability.)

 Grid charging of HR storage components:  The Proposal devotes considerable text to persuading Market Participants to bid HR storage component capacity into CAISO markets, even given the risk of losing ITCs.  The premise is that the current bid-price floor is sufficient to recover any lost ITCs.

The calculations of the bid-price needed to make up for ITC loss are complex, especially given the “cliff” for total ITC loss after the 25% grid-charging threshold is reached and the relevance of price “spreads” (and not just the bid-price floor level).  The Developers would be happy to work with CAISO in the future on this issue, e.g., when the CAISO is ready to consider further lowering the bid-price floor.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

High Sustainable Limit (HSL): 

The White Paper is a good start toward answering questions the Developers have been asking in numerous comments in this initiative, for many months.  For example, it clarifies that no new equipment will be needed to provide this measure.  However, it still does not address several fundamental issues, listed below. 

• What the CAISO is doing now.  It appears that the CAISO using the met data and information on available capacity to perform hourly forecasting and then using a “persistence” methodology for intra-hour forecasting.  Is this correct?  That is not clear in the White Paper.

• The CAISO’s current per-Generating Unit forecast accuracy and how much this additional requirement is expected to improve that accuracy.  If the CAISO is already performing well and/or the additional information won’t help much, there’s little justification for the additional requirement.

• How the HSL will be used.  For example, is the CAISO’s intent to simply use this value in place of the “persistence” measure in intervals when a resource receives a Dispatch Instruction?

• Why the CAISO itself (or its Forecast Provider) cannot incorporate this calculation as part of its forecasting function.  The CAISO will already have information on the amount of available VER capacity and met data from each project, so it is not clear why each and every VER CLR or VER HR component (or, eventually, each stand-alone VER) must modify its software to provide this information.  If the computational difficulty is the reason (especially given the proposed 10-second data granularity), then how does the CAISO expect each project to perform those calculations in the same timeframe?

• Most fundamentally, how the CAISO will ensure that each resource’s calculations are accurate and/or consistent with the CAISO’s forecasting methodology.

The CAISO already develops at least hourly forecasts using equipment availability and met data, with its Forecast Service Provider applying proprietary algorithms, global and other weather forecast data, information from nearby projects, etc.  However, the methods used by each resource to translate its equipment availability and met data into a 10-second forecast might not be the same as the CAISO’s provider, i.e., having each resource provide its own forecast could be “mixing apples and oranges.”  

This initiative is in the Draft Final Proposal stage, but the HSL issue is still in the White Paper stage (e.g., we have just received long-requested information and the CAISO is not near a Technical Bulletin yet).  Given the CAISO’s stated intent to examine expanding this requirement to all VERs in a future initiative, we suggest delaying imposition of this requirement to that future initiative, when the CAISO can provide more refined information and develop with stakeholders consistent policies across all the resources to which this requirement would apply.

HR outage/availability reporting proposal

• DL tool generally:  The Developers support this proposed tool.  The CAISO needs a system to inform it about VER production injected into storage, and the DL Tool seems well-designed to perform that function.

• Rest of the availability reporting framework:  The Developers strongly oppose this framework.  Specifically, the proposal for submission of availability information through both Outage Cards and the DL Tool, and for both lack of fuel (VER component) or State of Charge (SOC) (storage component), is:

• Unnecessary:  The DL Tool is the only one needed, and use should be limited, i.e., to: (1) VER injections into storage; and (2) real-time adjustments where the CAISO is not the VER forecast provider. 
  • Duplicative tools:  The two tools apparently provide the same information, but the DL Tool is more granular and better suited for the technologies involved.  The CAISO has not demonstrated any need for Outage-Card submittal also.
  • For VER capacity:  CAISO will have the same data for HRs as for VER CLRs and stand-alone VERs to calculate availability, other than use to fill storage; it readily does that for those facilities without the need for submission of additional information.  Thus, where CAISO is the forecast provider for the VER component, it should automatically adjust HR availability for VER fuel availability without the need for a DL Tool (or Outage Card) submittal, as it does for VER CLRs or stand-alone VERs.
  • For storage capacity:  CAISO will have the same data for HRs as from storage CLRs and stand-alone storage to calculate SOC/availability, and for which it readily does so without the need for submission of additional information.  Thus, CAISO should automatically adjust HR availability for SOC without the need for a DL Tool (or Outage Card) submittal, as it does for storage CLRs or stand-alone storages.

• Overly complex:  While the Outage Card submittal is supposed to cover unavailability that will “last through the Operating Hour” and the DL Tool is supposed to cover availability variations during the Operating Hour:”
  • Outage Cards and the DL Tool perform the same function – reporting availability to the CAISO – so the CAISO should not need both.
  • The combination only “works” in one direction, because the CAISO will use the lower availability indicated by these two tools.  So, Outage Cards can indicate a certain amount of Operating Hour unavailability, and the DL Tool can indicate additional unavailability within the Operating Hour.  However, if Outage Cards indicate a certain amount of unavailability, and the resource turns out to be more available than expected (e.g., higher VER production capability than forecast), then the HR must make a mid-hour Outage Card submittal for the higher production level, making the whole structure even more complex.

• Unduly discriminatory: 
  • The outage/availability process would not be required for CLR or stand-alone (VER or storage) resources using the same technologies.  The CAISO has not explained why the CAISO proposes these requirements for any reasons beyond VER capacity charging of storage capacity.  
  • The RA values of HR and CLR capacity would be different with the exact same technologies, availability, and performance (see below).  HRs would be subject to RAAIM applicability and UCAP reduction (see below) for weather-related VER variations and situations where the VERs are filling storage, while associated storage and solar CLRs would be not be subject to either for VER Resource IDs.

In addition, the RA impacts of the proposal:

• Are illogical, i.e.:
  • There is no reason why Outage Card submittals count for RAAIM/UCAP but DL Tool submittals don’t.
  • CLRs may have the exact same ITC limitations (storage can only be filled by VER capacity), but the RA value of neither the VER Resource ID nor the storage Resource ID would be reduced as a result.
  • If the HR VER capacity was not used to fill the HR storage capacity, other capacity on the system would have to be used for that purpose in order to make the storage capacity available to serve load reliably.  So, the use of VER capacity for this purpose is just as vital as the use of VER, gas, or other capacity from elsewhere to charge the storage capacity, and the net impact on the system is zero.

• Conflict with CPUC policies and procedures in its recent decision on RA value of mixed-fuel projects.  The CAISO proposal would:
  • Treat VER and storage capacity differently for RA purposes depending on whether they are configured as HRs or CLRs, though the CPUC decision clearly stated that RA value should be the same regardless of configuration.
  • Double-count RA value reductions due to ITC limitations.  The CPUC decision reduces VER Qualifying Capacity for mixed-fuel resources with ITC limitations to account for lower solar availability to the grid while filling the storage.  QC determines NQC and, for the proposed RA Enhancements framework, the new UCAP measure. 

The CAISO proposal would further reduce the UCAP value of HR VER components for exactly the same ITC limitations.

• Are inconsistent with the CAISO’s VER proposal under the UCAP framework.  The RA Enhancements Initiative would assign a UCAP to VERs (including VER CLRs) at the resource NQC, because the ELCC-based values that determine VER QC (and, therefore, NQC) already reflect forced outages.  However, the proposed availability-reporting system here would result in HR VER UCAPs below NQC if any forced outages are suffered, or even for normal weather-related variability, even though any QC values for HR VER components are also based on ELCC (and, therefore, are already adjusted for forced outages).

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

The Developers strongly support the ACC.  However, in past comments, we have provided to the CAISO many examples illustrating our understanding about how the ACC would work and requested that CAISO confirm the validity of these examples or provide its own.  The CAISO has done neither, to date. 

It was clear from the stakeholder meeting that there continue to be misunderstandings and lack of clarity even among otherwise-informed stakeholders.  This is disturbing when such an important initiative is at the Draft Final Proposal stage.

The Developers once again request that CAISO provide additional information and examples to show how the ACC would work.  At a minimum, we ask that CAISO confirm the general principles below.

• ACCs would only apply where multiple Resource IDs for a single Generating Facility “share” the POI capacity, or portions of it.  For example:

• Hybrid Resources assigned a unique portion of the Generating Facility POI capacity would not be included in an ACC, since their bids/schedules/Dispatch Instructions need not be optimized with other Resources at the same Generating Facility.

• “Stand-alone” VER Resource IDs assigned a unique portion of the Generating Facility POI capacity (i.e., that are not Co-located Resources) would not be included in an ACC, since their bids/schedules/Dispatch Instructions need not be optimized with other Resources at the same Generating Facility.

• VER and storage Co-located Resource IDs together (by definition) share a unique portion of the Generating Facility POI and have Pmaxes that total more than that POI capacity share.  Thus, they would be included in an ACC if optimization between them is necessary and if they desire that the CAISO provide that optimization through markets.

• A single Generating Facility can have multiple ACCs.  For example, a Generating Facility with two PPA off-takers could have two ACCs, one for each of two VER-storage CLR pairs.  Generating Facility owners would have flexibility to configure their projects with different mixes of ACC and non-ACC Resource IDs, and to change those configurations over time (e.g., as ITC limitations expire).

• A Generating Facility can have HRs (not in an ACC) and CLRs in one or more ACCs.  For example:

• The Generating Facility above with two PPA off-takers could have: (1) One Hybrid Resource ID for one PPA; and (2) two CLRs in an ACC for the other PPA.

• Another project could have: (1) One Hybrid Resource (not in an ACC); (2) one solar Resource ID (not in an ACC); and (3) two pairs of solar-storage CLRs, with each pair having its own ACC.  

• Generating Facility configurations can change over time as market rules and conditions,  PPA off-takers, and ITC applicability change.  Hybrid Resources can be reconfigured into Co-located Resources, and Co-located Resources can be reconfigured as Hybrid Resources.  CLRs can be re-grouped into different ACC groups as well.

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

The Developers appreciate CAISO’s inclusion of this proposal in Phase 2 of this initiative.  The CAISO’s proposal is conditioned on the following proposed rules (with some paraphrasing for clarity):

1. The flexibility would:

1. Be one-sided, i.e., apply only when the VER Resource ID is producing above its dispatch level.  The storage Resource ID could not increase output or reduce charging to make up for reduced VER output below Dispatch Operating Target (DOT).

2. Only apply when the additional VER energy would otherwise have to be curtailed.

2. No settlements changes would be provided, i.e.: (1) The Solar Resource ID would be paid for the positive imbalance; and (2) the storage Resource ID deviation would be charged as Uninstructed Imbalance Energy (UIE), including applicable uplifts e.g., FRP charges.

3. Prior approval is required, i.e., “capability must be demonstrated” to CAISO.

4. Neither resource can be providing Ancillary Services “at the same time.”

5. CAISO will not “share data” to enable this option, e.g., if two different SCs are involved, they must directly communicate information about the additional available VER Resource ID energy that can’t otherwise be produced, and any accommodating action by the storage Resource ID to enable that additional VER output.

Our comments about these conditions are below.

• Condition #1(b) – applicability:  Consistent with our comments on Condition #4 below, this condition should be refined to clarify that ACC capacity for the applicable CLRs be fully utilized for either Energy or A/S (once CLRs under an ACC can provide A/S), i.e. that the ACC POI capacity need not be fully loaded with Energy production to exercise this flexibility. 

For example, a 100 MW ACC containing 100 MW solar and 50 MW storage CLRs might have a solar Resource ID schedule of 50 MW of Energy and a storage Resource ID schedule of 40 MW of Energy and 10 MW of Regulation Up (headroom that must be left open at the POI to provide that service).  If the solar Resource ID can produce 60 MW in real time, the storage Resource should be allowed to reduce its Energy discharge to 30 MW to accommodate the additional solar production, leaving the 10 MW unloaded at the POI to preserve its ability to provide the Regulation Up service.

• Condition #2 – UIE vs. IIE:  The CAISO seemed uncertain about whether VER Resource ID production above DOT is considered UIE or IIE.  If this production is considered IIE, then logically storage Resource ID actions to accommodate the additional VER production should be considered IIE also.

• Condition #3 – Prior approval:  The CAISO should explain: (1) Why prior approval is needed; (2) how the “capability would be demonstrated to the CAISO;” and (3) when this demonstration would take place, e.g., in the New Resource Implementation Process (before COD) for new resources, and afterward for existing resources seeking this flexibility. 

• Condition #4 – A/S prohibition:  As a foundational matter, the CAISO should clarify that this prohibition would only apply to the intervals when the proposed operational flexibility would apply, and not that one or both Resource IDs could not be certified to provide A/S, for example.

More broadly, though, this “blanket” prohibition is unnecessary and should be revised to simply provide that exercise of this flexibility could not impair the ability of either resource to comply with any A/S awards. 

For example, a 100 MW storage CLR scheduled to provide 80 MW of energy and 20 MW of Regulation Up could reduce its output from 80 MW to 70 MW to allow an additional 10 MW of solar Resource ID production.  The 20 MW of “headroom” needed to provide the Regulation Up service would not be impaired in any way; in fact, because the storage SOC would be higher than otherwise, the storage Resource ID could be better able to provide that service.

• Additional accommodations:  Several stakeholders raised additional accommodations that the CAISO should consider to make the CLR configuration more attractive to owners and useful to the CAISO.  The Developers support this additional flexibility and encourage the CAISO to consider including these features in the CLR model.

• “One-way” flexibility (#1 above):  This condition is the same as in our proposal, and it is true that the two-way flexibility proposed by Flynn RCI at the stakeholder meeting would avoid VER curtailments and could leave storage Resource ID SOC below expected levels, raising concerns about ability to comply with later Energy or A/S schedules.   

Flynn pointed out that, if the storage Resource ID did not deviate to make up for the VER energy deficiency, some other grid resource must do that, e.g., a gas or another storage resource.  Thus, having the storage make up the VER deficiency wouldn’t leave the overall system any worse off.  The Developers believe that this argument is valid and ask that the CAISO consider this additional flexibility in this initiative.

• Netting deviations:  WPTF asked at the stakeholder meeting why CAISO could not net the positive solar and negative storage deviations.  The CAISO said that the current settlements software wouldn’t “know” that the two CLR Resource IDs were associated with each other.   

The Developers understand this limitation but believe that the CAISO should seriously consider this modification, since the net impact of the resources in the ACC on the CAISO system would be exactly the same with or without the deviations.  It should be included in this initiative if possible and, if not, in the next round of design modifications for mixed-fuel resources.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

•  DC metering:  The CAISO said at the stakeholder meeting that it is actively working on certifying a DC meter and expects that certification to occur around Fall 2021.  Developers with projects containing DC-coupled storage need more information about how this meter would be work under either the HR or CLR configurations, so that equipment can be successfully integrated into the respective project designs.

• Metering for storage charging energy:  Certain PTOs have recently added requirements for separate metering of charging energy for mixed-fuel resources, or at least HRs.  This requirement is not mentioned at all in the Proposal, and we do not understand the need for such requirements.  The CAISO should clearly explain the technical details and reason for this additional requirement, if any.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

The Developers would like to comment on an issue raised by WPTF at the stakeholder meeting, regarding the current CAISO practices for certifying VER-storage HRs to provide Regulation.  WPTF said that one of its members discovered that the CAISO would only consider the regulating range of the storage component and not the range for the entire resource.

The reason for this problem was not explained, and the CAISO could not say how or if the problem could be fixed.  Since stand-alone and CLR VER and storage projects can be certified to provide Regulation, it wasn’t clear why combining those technologies into a single Resource ID would cause problems, or why the Regulation range for one of the technologies would be disregarded. 

The CAISO did say that it believed that the problem could be fixed for provision of Operating Reserve (Spinning and Non-Spinning Reserve), so there shouldn’t be an issue with provision of those services by HRs.

It is highly problematic for such an apparently critical issue to surface so late in this process.

The CAISO should issue, as soon as possible (i.e., before issuance of the Final Proposal) a clear explanation of the Regulation problem and the options for quickly resolving it.  This information should also include confirmation that the problem does not exist for Spinning or Non-Spinning Reserve.
 

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

The Developers are puzzled by this question, since the Proposal did not appear to contain any Resource Adequacy information.  However, as noted above, we strongly oppose the application of Outage Cards, if required for HR availability reporting, to count against RAAIM under current RA performance framework and to reduce HR UCAP under the RA Enhancements Initiative proposed framework.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

Definitions and terminology:  The HR and CLR definitions, as well as much of the relevant terminology throughout the Proposal, were inconsistent with the CAISO’s proposed Phase 1 tariff language and also current CAISO tariff provisions.  (The Business Requirements Specifications suffered from many of the same inconsistencies.)  The Developers request that the CAISO use consistent terminology to refer to the same elements in the various CAISO documents, to prevent misunderstandings and confusion.

HR modeling

• NGR vs. GEN:  The CAISO’s 2016 Hybrid Resources Technical Bulletin stated that either the NGR or GEN model could be used, and it seems like the GEN model could apply where no grid charging of the storage component would be allowed.  The Developers asked in prior comments that the CAISO explain the conditions under which one model or the other would apply.

• VER vs. non-VER:  The Developers again ask the CAISO to explain why, when a gas-storage HR with a small amount of storage could still be treated as a gas generator, a VER-storage HR with a small amount of storage could not still be treated as a VER.  The CAISO has never acknowledged or explained this inconsistency.

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

Support with caveats

2. Provide a summary of your organization's comments on this proposal:

PG&E appreciates the opportunity to engage the CAISO and provide comments on the Hybrid Resource Initiative Draft Final Proposal. PG&E’s comments can be summarized as follows:

• Ancillary services eligibility requirements for hybrids should be the same as other participating resources.
• CAISO should provide more clarification on the optionality between the dynamic tool and outage cards, and whether automation can be accommodated within OMS system.
• CAISO should provide clarification as to whether the Pmax of a co-located resource can alone exceed the point of interconnection (POI).

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

The proposed use of outage cards requires more discussion by stakeholders.  PG&E is unclear if the CAISO is proposing additional outage notification requirements specifically for hybrid resources or if these requirements are parallel to other resource types.  Given the various and extensive data requirements (bids, high sustainable limits, dynamic limits, forecasts), PG&E would appreciate the CAISO mapping out how each of the data streams will be used in the market models.

The CAISO should also explore the maximum extent to which this information sharing can be automated.

PG&E appreciates the CAISO’s inclusion of Section 4.11. It would be further helpful to use standard conventions such as always indicating charging as negative.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

Please refer to the comments on the market interaction topic and the resource adequacy topic.

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

PG&E supports the Draft Final Proposal’s enhancement to include ancillary services in the aggregate capability constraint by Fall 2021.  However, PG&E’s support is based on an assumption that hybrid resources can be certified to provide ancillary services in exactly the same way as existing resources.  For example, regulation certification is based on a test of a resource’s capability to regulate between a minimum and maximum level which are then used to bound what market participants may set as minimum and maximum regulation limits in the CAISO’s master file.  Regulation can thus only be provided when the resource has a set point between the master file minimum and maximum regulation limits.  Any change to this definition of regulation capability would be a change in the requirements of regulating resources and should be reviewed by a wider range of stakeholders than just those developing hybrid resource projects; therefore, such changes should not be in the scope of the final proposal.

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

PG&E considers the list of circumstances (on page 16 of the Proposal) permitting a storage resource to deviate from dispatch reasonable. However, more clarification is needed regarding the numerical example provided on page 17. Specifically, the example should be modified and/or expanded to address the following items:

• The Pmax of the solar resource should not exceed the point of interconnection (POI) constraint. In the example, it is suggested that the solar resource has a maximum operating limit which exceeds the interconnection rights of the co-located project. The CAISO should respond as to whether this scenario is possible given the Pmax of such a resource is typically be clipped at the POI in the generator interconnection agreement. The CAISO has addressed the scenario where the aggregate values of maximum operating limits exceeding the POI, but not the situation where one resource’s output alone exceeds the POI.

Additionally, more details on the settlements calculation should be provided. PG&E understands that the intent of keeping the settlements for storage deviations unchanged is to allow the UIE charges applied to storage resources to be offset by the increase in RTD revenues from the additional VER output. However, the CAISO has not described the impacts to DA settlements—this further detail is necessary to understand how resources with DA schedules are affected.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

Also, the CAISO should explicitly state that both metering entity paradigms (ISOME and SCME as described in the BPM for Metering) will be maintained for hybrid and co-located resources.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

PG&E agrees with the CAISO that hybrid and co-located resources should be subject to the same ancillary service eligibility requirements as other participating resources. There should be no special case(s) made for hybrid and/or co-located resources that would allow them different treatment or an alternative certification process to that described in Appendix K of the CAISO tariff.

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

In general, it seems more appropriate to assess how much a hybrid counts towards resource adequacy in the calculation of its QC, rather than mandating a 24x7 MOO. Recently, the CPUC adopted a new dispatchable hydro counting methodology which reflects historical conditions. Resources that adopt this methodology do not face RAAIM. Hybrid resources with charging limitations may be a parallel to hydro with limited storage. As long as the QC reflects the charging limitations, the MOO should be similarly bounded.

PG&E appreciates the CAISO’s acknowledgement of the challenges regarding a 24x7 DA MOO for hybrid resources. Given the inherit uncertainty of the VER component, the CAISO should ensure that appropriate must offer obligations are put into effect which do not punish a hybrid resource for VER/EIR forecast error present in the DA timeframe. PG&E raised this concern in its comment on a previous version of the Straw Proposal (Page 9 found here: http://www.caiso.com/InitiativeDocuments/PG-EComments-HybridResourcesStrawProposal.pdf).

The introduction of the dynamic limit does have the potential to address this concern, so long as it is included in the calculation of the RT MOO. One way to do this is to define a hybrid’s RT MOO as the lesser of: (1) its DA MOO and (2) the upper economic limit submitted as a part of the dynamic limit tool.

Additionally, the calculation of a hybrid resource’s UCAP under the RA enhancements paradigm should include reductions in capability due to the dynamic limit submissions.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

none

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

SDG&E appreciates the opportunity to comment on the draft final proposal.  SDG&E believes the CAISO proposal creates tremendous administrative burden and could lead to sub optimal market awards for hybrid and co-located resources. SDG&E believes there are still some issues that must be addressed as some components of the proposal remain unclear; especially given the interaction with CAISO’s other initiatives such as day ahead market enhancements, energy storage and distributed energy resources phase 4, and resource adequacy enhancements, that also include proposal that impact energy storage, hybrids and co-located resources.  SDG&E believes the CAISO should consider all such changes and provide stakeholders a clearer understanding of how these resources would participate and be impacted by the various initiatives as a whole rather than piecemeal.    

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

High Sustainable Limit (HSL): SDG&E supports the proposal for the HSL for the variable energy resource (VER) component of a hybrid or co-located resource.  SDG&E understands that the HSL should provide the CAISO with the ability to create a more accurate forecast for market optimization, particularly for a co-located resource.  Without the HSL, the CAISO would either rely on the telemetry data or ignore the telemetry data for its forecast.  SDG&E requests the CAISO to respond to the following questions in the next iteration of the proposal:

• The HSL white paper includes definitions for Hybrid and Co-Located Resources.  It is confusing why the definitions in the white paper is different from the definitions in the proposal.  Is the CAISO proposing to change the definitions?
• The CAISO notes that HSL will improve the day-ahead forecast because of the data that will be provided through the SCADA system.  SDG&E requests the CAISO to clarify how the day-ahead VER forecast differs from the real-time VER forecast in its usage of the HSL.

SDG&E understands day ahead market interaction process for hybrid and co-located resources as follows:

For Hybrid resources, the CAISO will use information, such as the HSL, telemetry and state of charge (SOC), to dispatch the hybrid resource day ahead.  If the resource is unable to generate up to its PMAX, then the resource must submit an outage to inform the CAISO of such dispatch limitations.  In real time, the SC must update the outage card as well as use the dynamic limit tool to further limit real time awards.  SDG&E does not support the CAISO’s proposal to require SCs to submit outages during the day ahead process to reflect the output capability of the hybrid resource.  This results in sub optimal results for market awards because the ISO seems to only view the hybrid resource as a traditional thermal generator that limits its “pmax” capability rather than a true hybrid resource that has two or more fuel types.  SDG&E believes the CAISO should model the hybrid resource as a VER and allow the bids to dictate how much energy would be put onto the grid.  This is because the CAISO is still receiving or generating the forecast for the VER component as well as the SOC for the energy storage device.  By combining these two components as a “forecast”, the CAISO’s market optimization should yield a more efficient result day ahead solution.

For co-located resources, the CAISO requests similar resource information from both resources.  However, because the CAISO treats the two resources as unique resources, the CAISO will continue to provide forecasting services for VER while maintaining the SOC for the storage resource separately.  The only limitation is the point of interconnection (POI) in which the co-located resources must not exceed.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

Dynamic Limit Tool:  The CAISO proposes to create a Dynamic Limit Tool (DLT) for hybrid resources which can limit the economic dispatch of the hybrid resource for the real time market.  This dynamic limit would be submitted to the ISO once every 5 minutes, on a 5-minute interval in a three hour window.  The CAISO proposes to that SCs submit outage tickets for real time as well, similar to the day ahead process for an hourly window.  Then the SC would update the outage on an hourly basis but also update the DLT on a 5 minute basis.

While SDG&E does not find major issues with the DLT, SDG&E does object to the requirement to submit outages in addition to the submittal of the DLT information in real time.  The outage information is duplicative, administratively burdensome, and could potentially interfere with the DLT information.  If the outage derate lowers the output from 100 MW to 75 MW due to the solar forecast, but the DLT then later shows the resource output to be at 85 MW, then it seems the market optimization would limit the dispatch to only the outage derate because the ISO requires the SC to update the outage value once per hour for the entire hour.  If the SC must update the outage every 5 minutes to sync up with the DLT value, such updates would be extremely burdensome for the SC.  Additionally, even though updates submitted through the DLT would not be subject to resource adequacy availability incentive mechanism (RAAIM), the outage derates would subject the hybrid resource to RAAIM.  SDG&E believes the CAISO should NOT require the hybrid resource to submit outage derates to reflect forecast output of the hybrid resource.  Rather, SDG&E believes the CAISO should utilize information from the DLT, HSL, SOC and the resource’s bids to optimally dispatch the resource in real time.  It may be the responsibility of the SC to structure the bid such that the storage component charges from the on-site renewable resource rather than have the on-site renewable resource output to the grid until the CAISO gains the computational prowess to optimize the SOC of the storage component at a later time.

SDG&E requests the CAISO to provide additional details on the acceptable lag if the SC depends on the CAISO for the VER forecast.  It is unknown how much time it would take for the SC to receive the data and process it to create the DLT for each hybrid resource and then resubmit to the CAISO.  Additionally, it is unclear what happens if the ISO does not receive updated DLT every 5 minutes.

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

SDG&E supports the proposal to enable ancillary service for co-located resources by fall 2021.

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

SDG&E understands the need to limit output from co-located resources to produce below the POI limits.  However, SDG&E believes the CAISO must better explain its proposal for when the resource may not deviate and what occurs when that happens.  For instance, the CAISO proposes to limit deviation from only the storage resource when the co-located resources are producing above the POI limits.   The CAISO does not provide any details of whether the co-located resources would be allowed to deviate when the output does not exceed the POI limit.  In cases when the POI limit is not exceeded and the VER resource is producing below dispatch, would the storage resource be allowed to deviate to cover the gap?  In cases when the POI limit is not exceeded and the VER resource is producing above dispatch, would the storage resource be allowed to lower its discharge? 

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

SDG&E is generally supportive of the metering requirements.  SDG&E requests the CAISO to clarify whether separate metering will be required at the 12kV level only or could one meter be at 12kV while the others are at a 480V level.  Additionally, SDG&E would like to better understand how ancillary services would be monitored for the hybrid and co-located resource configurations.

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

No comments.

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

As noted above, SDG&E does not support the proposal to submit outage cards to notify the CAISO of non-mechanical outages for purposes of dispatch.  SDG&E believes the CAISO must clarify the proposal because it seems to contradict the need for such outage cards. 

The ISO further recognizes that the hybrid resources with variable energy components may not be able to bid the full resource adequacy capacity because of potential for variable underlying resources. Non-availability due to the variable nature of a hybrid component is understood by the ISO. These kinds of variability need not be reported to the ISO with an outage card, but may be captured in the dynamic limits of a hybrid resource to the extent that the variability is occurring intra-hour. If a portion of a resource is unavailable for the full duration of an hour, the resource is required to submit an outage card through the ISO’s outage management system (OMS). (p 26. Emphasis added)

The CAISO’s own examples show that these kinds of variability need to be reported to the ISO with an outage card for both day ahead and real time.  Yet the proposal language suggests it does not.  Assuming the variability of the VER must be submitted to the CAISO, this would subject the hybrid resource to RAAIM charges.  Given that the hybrid resource’s qualifying capacity value is already adjusted for outages as part of the expected load carrying capability (ELCC) methodology; including RAAIM charges would seem like a double penalty.  This is the exact reason to which the CAISO exempted Solar and Wind resources from RAAIM. 

SDG&E requests the CAISO to further discuss how these hybrid and co-located resources would participate under day-ahead market enhancements with the new capacity products.  Additionally, would the energy storage component of the co-located resource be required to utilize both the end of hour state of charge and minimum charge requirement parameters proposed in other initiatives?  If so, how would those work with the deviation limitations and the point of interconnection constraints?

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

SDG&E is concerned with the CAISO proposal to provide special exemptions for resources to not show the capacity in the market under the investment tax credit (ITC) section of the proposal.  SDG&E believes the CAISO should not create such exemptions because it undermines the RA program to ensure available capacity participates in the market. The CAISO has rejected a resource’s ability to withdraw from the CAISO market due to financial reasons in the past, SDG&E would like the CAISO to clarify why such exemptions should be granted now.

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

As a general matter, the Six Cities do not oppose the CAISO’s Draft Final Proposal and, as discussed in more detail in response to the various questions posed by the CAISO, support discrete elements of the proposal. 

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

The Six Cities do not have specific comments on this element of the Draft Final Proposal. 

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

The Six Cities do not have specific comments on this element of the Draft Final Proposal. 

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

The Six Cities do not have specific comments on this element of the Draft Final Proposal. 

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

The Six Cities support the CAISO’s proposal to permit co-located storage resources to deviate from the CAISO’s dispatch instructions in the event that the VER resource component is capable of producing additional energy above dispatch, as proposed in the Draft Final Proposal.  The Six Cities acknowledge the limitations placed on this proposal, including the requirement that the resource not be providing Ancillary Services and not otherwise produce above the point of interconnection limits.

Although the Six Cities support this element of the CAISO’s proposal, the Six Cities are concerned that the CAISO’s proposal to permit deviations from dispatch instructions in specified circumstances does not go far enough in accommodating deviations that are both reasonable and needed in connection with a resource’s accessing of the Investment Tax Credit.  Specifically, the CAISO should expand its proposal to permit storage resources that are charging to also reduce their level of charging activity in response to a reduction in production by the associated variable resource.  This is essential to ensure that storage resources with Investment Tax Credit-related restrictions on grid charging are not inadvertently exposed to grid charging if production from the co-located variable resource is reduced. 

The Six Cities are also concerned that, while deviations by storage resources from dispatch instructions are permitted if necessary due to fluctuations in the production by the associated variable resource, such deviations are being unduly penalized, because they will result in the assessment of Uninstructed Imbalance Energy (“UIE”) charges.  The Six Cities request that the CAISO re-evaluate if the imposition of UIE in response to storage resource dispatch deviations represents a reasonable policy choice. 

Finally, the Six Cities seek confirmation that this functionality is optional and may be elected on a resource-specific basis. 

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

The Six Cities do not have specific comments on this element of the Draft Final Proposal. 

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

The Six Cities do not have specific comments on this element of the Draft Final Proposal. 

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

The Six Cities do not oppose the CAISO’s proposals with respect to Hybrid Resources and Resource Adequacy (“RA”).  However, the Six Cities urge the CAISO to carefully consider the interrelationship between RA-related determinations in this proceeding and the changes under consideration in the RA Enhancements initiative.  As market participants seek to deploy battery storage technology in the coming years, it is critical that the CAISO and its stakeholders take adequate time to ensure that the CAISO’s market rules and the RA implications of batteries are well-understood.  The Six Cities believe that stakeholders would benefit from a discussion of the RA-related elements of the Hybrid Resources and RA Enhancements proposals, including information that provides a direct comparison of the RA obligations and requirements for storage resource components under both the Hybrid and co-located resource models.  The CAISO should be erring on the side of providing greater clarity and examples of how storage resources will be eligible to provide RA as storage procurement expands in the coming years.  Moreover, the Six Cities urge the CAISO to ensure that the RA rules are neutral as to both models and do not provide a preference or favor one model over the other.  The decision to use the Hybrid or co-located models should be driven by commercial considerations – including Investment Tax Credit requirements, which are of critical importance to the development of the storage resource component – and the CAISO’s RA rules should take into account such commercial limitations to avoid imposing conflicting requirements on how a storage resource may participate in the market. 

With respect to the proposal for a “24x7” Must Offer Obligation (“MOO”) for Hybrid Resources, the Six Cities note the CAISO’s acknowledgment that there will be times that a Hybrid Resource is incapable of bidding into the market.  The 24x7 MOO requirement presents even greater challenges for a co-located battery system.  A 4-hour or 6-hour duration battery is the industry norm today, and it will be nearly impossible for such a battery to meet the 24x7 MOO requirement unless CAISO provides clear flexibility and direction regarding the bidding rules.  The Six Cities understand the CAISO’s proposal is to use outage cards to reflect these periods of unavailability.  Although the CAISO has provided stakeholders with a limited example of how this outage process may work, the Six Cities urge the CAISO to continue to provide additional information and examples to educate stakeholders on the envisioned use of outage cards.  More fundamentally, however, the Six Cities are concerned that the outage card process proposed by the CAISO will be both administratively cumbersome and error-prone and result in inappropriate derates of storage resources’ UCAP values.  Under-counting the RA value of storage resources, particularly given the expectation of expanded storage resource deployment in future years, benefits no one.  The Six Cities urge the CAISO to address this concern and, if necessary, to consider use of an alternative mechanism or tool to reflect storage resource availability. 

The Six Cities do support the CAISO’s proposal that variability in the availability of a Hybrid Resource due to the variable components of the resource may be reflected in the resource’s dynamic limits and will not result in RA Availability Incentive Mechanism (“RAAIM”) penalties.

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

The Six Cities have no additional comments at this time. 

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

Southern California Edison (SCE) is generally supportive of the California Independent System Operator’s (CAISO) Final proposal[1] and reiterates its prior comments[2].

High Sustainable Limit (HSL)

SCE is supportive of this component and believes that the benefit from the HSL is significant. SCE understands that the CAISO should have information on the maximum production capability of the Variable Energy Resource (VER) component of a Hybrid Resource (HR) and a Co-Located Resource (CLR). All informational attributes of a VER are not necessarily present in outage cards and are not communicated to the CAISO through other means. Further, SCE supports that any relevant calculations toward determining HSL should be performed at the resource prior to communication.
SCE believes that to realize the benefits from such a proposal, the CAISO should allow SCs an option to automatically have the HSL data incorporated into the RT bids of both HRs and CLRs. The existing RT bid deadline of T-75 (and hourly updates) can be streamlined with a more efficient and accurate process of directly incorporating HSL information rather than unnecessarily requiring SCs to do so. As this would be an option, it still provides for SC involvement but with this option, more accurately incorporated data would essentially replace the VER forecast for CLR VERs and would allow more dynamic participation from both HRs and CLRs, benefiting the CAISO’s needs as well.

Dynamic Limit Tool (DLT)

SCE is generally supportive of this component contingent on the understanding that this remains an optional component. SCs have the option of using the DLT to report 5-minutely information to the CAISO, should they choose. However, SCE understands that SCs retain the right to only use the Outage Management System (OMS) if they wish to report any output capability that deviates from forecast capability. SCE also understands that any reported capability would be the minimum of the reported capabilities of either the OMS or the DLT.

However, SCE is still unclear on the understanding of the proposal regarding the DLT treatment against existing bid curve information. , The CAISO should clarify whether DLT will overwrite the resource’s  bid curve, and if so, then clarify the specific price-quantity function that is honored by the CAISO. The CAISO should elaborate on whether the price-quantity relationship specified in the bid curve is maintained even after a DLT specification truncates parts of the bid curve.

SOC submission

SCE supports the requirement for CLRs and HRs to provide SOC telemetry from their storage component to the CAISO.

CLR storage deviation from dispatch

SCE supports the CAISO’s approach in addressing this part of the proposal. Specifically, that all deviations are treated as UIE, that the capability is the burden of the SCs, and is only allowed when CLRs may produce above POI due to overgeneration of their VER components.  SCE believes that such prudent measures should provide sufficient safeguards against inappropriate behavior.

Regulation and UCAP

During the August 10, 2020 stakeholder call, issues were brought up regarding how the proposal may prevent a hybrid resource from providing regulation services and how the proposed application of outage cards may impact the UCAP value of the resource. These issues were not documented, nor addressed, in the Draft Final Proposal.  SCE believes that the issues surrounding the provision of Regulation from a hybrid resource should be within scope for this stakeholder process.  The issue of UCAP could be deferred to the CAISOs RA Enhancements Stakeholder process or could be addressed within this Stakehoder Process.  Either way, it should be addressed to provide the clarity necessary to market participants.

[1] http://www.caiso.com/InitiativeDocuments/DraftFinalProposal-HybridResources.pdf

[2] http://www.caiso.com/InitiativeDocuments/SCEComments-HybridResources-SecondRevisedStrawProposal.pdf

2. Provide a summary of your organization's comments on this proposal:

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

1. Please provide your organization’s overall position on the Hybrid Resources draft final proposal:

2. Provide a summary of your organization's comments on this proposal:

Overall Wellhead is very supportive of the CAISO’s proposal and only seeks clarifications on the necessity of outage cards and the use of SOC data

3. Provide your organization’s feedback on the market interaction for hybrid resources proposal, as described in the draft final proposal:

The CAISO should clairify why outage cards are needed when a hybrid battery is charges from its internal generator. If a hybrid resource submits economic bids that do not result in the dispatch of the resource in the positive output range, then the hybrid resource should “economically” store the excess energy by charging its internal battery. That is, to the extent a resource is following its dispatch (or lack thereof) no outage card should be required.

If the resource wants to self-schedule an “internal charge” an outage card or self-schedule may be required. The CAISO may want to examine self-scheduling in this case as an alternative to outage cards that function better in the UCAP environment.

Wellhead also requests the CAISO provide specific examples of how the CAISO will use the SOC data. As with “economic” self-charging example above, we just want to make sure that, provided the resource follows its dispatch, CAISO will not constrain hybrid operations.

4. Provide your organization’s feedback on the forecasting and dynamic limits proposal, as described in the draft final proposal:

Wellhead supports the CAISO’s proposed dynamic limits tool. 

5. Provide your organization’s feedback on the proposal to enhance the aggregate capability constraint for co-located resources, as described within the draft final proposal:

Wellhead supports CAISO’s proposal to enhance the aggregate capability constraint for co-located resources

6. Provide your organization’s feedback on the proposal to allow co-located storage resources to deviate from dispatch instructions to allow for offsetting VER variation, as described within the draft final proposal:

Wellhead supports this proposal understanding that it should seldom be required as under normal circumstances, and with appropriate bid sets submitted, the CAISO will naturally dispatch the two resources so that no deviation is required.

7. Provide your organization’s feedback on the metering topic, as described within the draft final proposal:

Wellhead supports the CAISO’s proposal for metering

8. Provide your organization’s feedback on the ancilliary services proposal, as described within the draft final proposal:

Wellhead supports the CAISO’s proposal for ancillary services

9. Provide your organization’s feedback on the resource adequacy topic, as described in the draft final proposal:

Wellhead supports the CAISO’s proposal for RA with 24 X 7 MOO

10. Provide any additional comments on the draft final proposal for the Hybrid Resources initiative:

Wellhead is concerned that using price spreads, instead of prices, to optimize hybrid NGRs may not be appropriate. Using price spreads could become overly complex when the hybrid unit’s charge range is not symmetrical with its discharge range. Wellhead requests that the CAISO engage with NGR and Hybrid NGR participants to further explore this topic