Provide your organization’s comments on the ACC final proposal:
EXPEDITED TREATMENT OF ACC ELIGIBILITY EXPANSION
LSA and SEIA repeat their request from the last stakeholder meeting (supported by other attendees) that the CAISO ask for expedited processing for the ACC applicability expansion from FERC, and revise any needed internal procedures to accommodate implementation as soon as possible. Resources needing this feature are coming on line now and in the very near future; based on the HRI stakeholder process, developers of these projects expected that this capability would be available last Fall, and it is urgently needed for these new facilities.
The delay is also causing developers problems concluding Power Purchase Agreement (PPA) negotiations for future resources. PPAs are now “on hold” as off-takers wait for confirmation that they will be able to get the separate scheduling and settlement provisions they need from new contracted resources.
MSATER ACC REQUIREMENT
This requirement should be removed.
First, the CAISO should clarify that MFRs configured as CLRs do not need any ACCs at all (master or otherwise) if they have sufficient capacity at the Point of Interconnection (POI) to accommodate full output from both CLRs. While this configuration is not typical, the pre-ACC convention of dividing the POI limit between the CLR Resource IDs can be used, and therefore no ACC is needed.
Second, the CAISO has yet to explain the need for a Master ACC when all the Generating Facility capacity is covered under “Sub-ACCs,” or the prior practice for dividing capacity at the POI.
- Where all the capacity for a Generating Facility is covered under Sub-ACCs, each Sub-ACC would have a maximum limit for scheduling and real-time dispatch, and those limits would total to the POI limit of the Generating Facility. The required POI controls would ensure that real-time output of the entire Generating Facility does not exceed the limit.
- Where all the Generating Facility capacity is not covered under Sub-ACCs, the pre-ACC convention dividing up the POI capacity would yield the same result without a Master ACC. In other words, ACCs are only needed where POI capacity use for scheduling and dispatch covers shared POI capacity, and not otherwise.
For example, assume a 100 MW MFR Generating Facility with three Resource IDs: (1) Solar and storage CLRs with a 70 MW ACC limit; and (2) a Hybrid Resource (HR) Resource ID with the remaining 30 MW. The CAISO’s Master File rules would require the POI capacity to be split between the 70 MW ACC resources and the 30 MW HR.
The ACC would ensure that the CLR scheduling and dispatch do not exceed 70 MW, and the 30 MW Pmax for the HR would ensure that scheduling and dispatch for that Resource ID does not exceed 30 MW. Thus, there is no need for a Master ACC to ensure that scheduling and dispatch for the Generating Facility does not exceed the allowed levels.
Finally, the CAISO has not explained how or if a Master ACC would interact with Sub-ACCs, or why it would be needed given the rest of the resource configuration.
In summary, because all MFR Generating Facility Resource IDs would be covered by either Sub-ACCs or conventional Pmax splits, the requirement for a Master ACC should be removed. The CAISO should avoid superfluous requirements in the absence of any need for them.
BOUNDARIES BETWEEN ACCs
LSA and SEIA strongly believe that the CAISO should not “breach” the boundaries between ACCs at the same Generating Facility in real time except under the same conditions – System Emergencies – as for separate Generating Facilities. As explained further below: (1) There is no rationale for its proposal to breach ACC boundaries under less-dire circumstances (before the “power balance” constraint); (2) it is likely to lead to unintended consequences that the CAISO does not want; and (3) the CAISO’s proposal is unworkable.
Lack of rationale: CAISO’s own diagrams show that there is no rationale for its proposal to treat ACCs different from separate Generating Facilities.
Below is the diagram in Slide 7 of CAISO’s June 3 meeting presentation, showing CLRs in two different ACCs at one Generating Facility (“Situation 1”). Each ACC has its own part of the POI capacity, at 110 and 123 MW, respectively.
LSA and SEIA maintain that this is exactly the same diagram that would be used to illustrate two separate MFR Generating Facilities – 110 and 123 MW, respectively – sharing a single gen-tie line (“Situation 2”). The fact that Situation 1 CLRs would be under one GIA and Situation 2 CLRs would be under multiple GIAs has absolutely no bearing operationally.
In other words, more generally, multiple ACCs for a single Generating Facility and multiple Generating Facilities sharing a single gen-tie are “similarly situated.” Treating similarly situated resources differently without justification is the very definition of “unduly discriminatory.”
Unintended consequences: The above diagram makes is clear that developers could work around the CAISO proposal simply by installing the exact output-limit controls for Situation 2 as the CAISO mandates for Situation 1 – namely, software or equipment limitations that prevent ACC resource on the left collectively from physically exceeding their allotted share of POI capacity. The CAISO said at the June 3rd meeting that it “prefers” that developers not install these limitations, but it likely that they will become common should the CAISO adopt this proposal.
Lack of workability: The proposal is unworkable, because it:
- Would confound numerous already-executed PPAs. Most PPAs for resources coming on line now and in the next couple of years have been long executed, based on the CAISO’s long-standing historic treatment of multiple-Resource ID Generating Facilities to date and, more recently, representations in the HRI stakeholder process. The CAISO’s entirely new proposal here was obviously not contemplated when those contracts were negotiated, and the proposal has raised fears among off-takers that they will not receive the products and services they have contracted to pay for.
- Would make larger Generating Facilities less valuable, because presumably it would result in potential ACC boundary breaches more frequently than for System Emergencies.
It is extremely efficient, for both CAISO and Interconnection Customers, to structure new Generating Facilities as large projects in the interconnection request and study process, and then split them contractually later. Larger projects cost less to process than multiple smaller projects with the same collective capacity, and they impose lower workload burdens on the CAISO and PTOs in the study and GIA development process.
However, the CAISO proposal would provide more protection to off-takers for smaller but separate Generating Facilities than those that are portions or phases of larger Generating Facilities. The result could be a proliferation of smaller projects in the interconnection process – say, a Cluster 15 workload for the CAISO and PTOs of two or three time the 377 projects in Cluster 14.
- Lacks any recognition of practical implementation issues. For example, there is no indication of how frequently the specified conditions could occur, exactly what actions the CAISO may take under those conditions, or how or when Market Participants would be notified of these conditions or actions.
Conclusion: The proposal to allow ACC breaches “just before” the power balance is relaxed is unjust, unreasonable, unduly discriminatory, and unworkable. It is likely to draw a challenge at FERC for those reasons, and the CAISO should withdraw this proposal.
PSEUDO TIE ELIGIBILITY FOR ACCs
The CAISO should remove its prohibition on use of ACCs by Pseudo Tie resources. Like the ban on multiple ACCs per Generating Resource, this prohibition was included in the cover letter for the HRI Phase 1 tariff filing without any vetting or even mention in the stakeholder process, and there is no substantive reason for continuing it.
The CAISO tariff filing stated as follows, on p.9 (emphasis added):
For resources using other modeling constraints it may be problematic to apply an aggregate capability constraint that could conflict with existing constraints for purposes of issuing market awards or dispatch instructions. For this reason, and out of an abundance of caution, the CAISO has proposed that the following resource types will be ineligible to use the aggregate capability constraint: Multi-Stage Generators, Pseudo-Tie Resources, Proxy Demand Response, Pumped Storage Hydro Units, Metered Sub-Systems, and Use-Limited Resources. These resource types have yet to express an interest in using an aggregate capability constraint in the CAISO’s stakeholder initiative, and there are very few, if any, of each type in the CAISO interconnection queue.24 Expanding the aggregate capability constraint to these resource types would create significant additional complexity in implementing the constraint this year.
With all due respect:
- No evidence was presented (see above, e.g., no vetting in the HRI stakeholder process) to support any conclusion that “modeling constraints” related to these resource types could cause any conflicts with the ACC construct. Even the CAISO language only says it “may be” problematic, hardly a strong case for excluding resources from a vital market tool.
- The filing allows EIM Resources to qualify for ACCs, even though those resource are certainly subject to many “modeling constraints.” There appears to be no basis for concluding that those “modeling constraints” would be any less problematic for ACC eligibility than those for the resources listed here or, conversely, that the modeling constraints for the listed resources would be any more problematic than those for EIM Resources. At least the other resources (including Pseudo Tie Resources) are part of the CAISO BAA, unlike EIM Resources.
- With respect to potential MFR Pseudo-Tie Resources specifically:
- There would be no reason for developers of these resources to “express interest” separately from other developers in the HRI stakeholder process, since there was no indication that the CAISO had any intent of excluding them from ACC eligibility.
- Developers of these resources are often not different entities than developers of CAISO-area resources, who have actively participated in the HRI. Certainly, LSA members are developing MFRs outside California that will likely use the Pseudo Tie model to sell into California, in addition to CAISO-area resources.
- There is no way they can be listed in the CAISO Interconnection Queue, since they do not submit Interconnection Requests to the CAISO, only to their Host BAA.
- These resources simply will not be able to participate in CAISO markets if they cannot use ACCs, for the same reason that ACCs were needed for market participation by CAISO-area MFRs, i.e., the different fuel types could not share POI capacity.
- Any concerns regarding transmission reservations should be resolvable as part of establishing the Pseudo Tie and associated ACC. Instead of demonstrating that they have sufficient transmission reserved for the total capacity, they would have to demonstrate that they have sufficient transmission reserved for the interconnection-service capacity, and the ACC would "connect" the applicable Resource IDs for this purpose.
- These resources are at least part of the CAISO BAA, unlike EIM Resources, which are eligible to use ACCs.
Since the CAISO’s statements in the filing regarding Pseudo Ties (at least) cannot be supported, there is no apparent reason for excluding MFR Pseudo Tie Resources from ACC eligibility. Thus, the CAISO should revise this policy and allow Pseudo Tie Resources to qualify for ACCs.
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