Comments on Scoping document

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

ACP-California appreciates CAISO ongoing efforts to improve the interconnection process and help promote timely interconnection of new resources. Generally, ACP-California believes that CAISO’s IPE 5.0 Scoping Document has captured the items that it committed to revisit during the last IPE initiatives and associated discussions. ACP-California looks forward to reviewing CAISO’s forthcoming IPE 5.0 Straw Proposal. We are particularly interested in continuing to consider opportunities for Energy Only projects to re-enter the queue and be studied for deliverability as well as consideration of appropriate treatment of long lead-time resources, such as allowing deferment of their first opportunity to seek a Transmission Plan Deliverability (TPD) allocation. We look forward to engaging with CAISO on the IPE 5.0 proposals.

In addition to the items included in the IPE 5.0 Scoping Document, ACP-California urges CAISO to add another item for consideration within IPE 5.0. This item would be used to explore – over the course of the IPE 5.0 initiative and as progress occurs on near-term procurement – whether any necessary process changes are appropriate and required for Cluster 14 (or earlier) projects. Given recent changes to federal rules, it is likely that Cluster 14 projects are the last set of CAISO-queued solar and wind resources which may be able to secure tax credits under the Inflation Reduction Act (“IRA”).[1] And these projects will need to demonstrate commercial readiness on an expedited timeline. Per current CAISO proposals from IPE 2023 Track 3, projects that receive a Group B or D allocation as part of the upcoming 2025 TPD allocation cycle will need to be able to attest to having an executed PPA ahead of the Q1 2027 TPD affidavit deadline, or they will be converted to Energy Only. In order for resources to achieve this milestone, and to continue forward with full tax credit eligibility, procurement needs to be initiated in the next few months. ACP-California is actively working within the CPUC’s Reliable and Clean Power Procurement Program (“RCPPP”) to support CPUC action on near-term procurement and is optimistic that this type of CPUC procurement activity could be accomplished in time to support PPA execution for Cluster 14 and earlier projects by the Q1 2027 deadline. However, there remains significant uncertainty and ACP-California urges the CAISO to leave an open item in IPE 5.0 to explore, as the CPUC’s RCPPP process moves forward, whether any additional modifications/timeline adjustments are needed for Cluster 14 (or earlier clusters) to address 2028-2032 system needs and maximize ratepayer benefit through access to IRA tax credits.

In addition to adding an item to consider the immediate procedural needs of Cluster 14 projects, ACP-California urges CAISO to use the IPE 5.0 initiative to resolve the fundamental commercial and regulatory impasse created when projects are assigned Long Lead-Time Deliverability Network Upgrades (LLT DNUs). The current framework can assign an 8 to 10+ year upgrade timeline to a project that can be energized in 2 to 4 years, which creates a situation that is nearly impossible to navigate, from a commercial perspective. This, in turn, undermines market certainty and jeopardizes California’s ability to meet its reliability and clean energy goals. CAISO has already acknowledged the severity of this issue in past IPE discussions. And in its IPE 2023 Track 3 Final Proposal, CAISO noted that developers facing LLT DNUs “may withdraw before incurring additional financial risk”[2] which is not a long-term solution to the current challenge. Failure to develop solutions outside of withdrawal is highly problematic and effectively places the burden of a systemic grid planning deficiency onto individual interconnection customers. The time to consider potential solutions to this ongoing issue is now, otherwise we risk unnecessarily prolonging ongoing challenges with resource interconnection and energization in California, jeopardizing the state’s ability to deliver reliable and clean power. We look forward to working with CAISO and stakeholders to develop these critical solutions.

[1] Pre-Cluster 14 projects still in the queue are also candidates for these tax credits, but Cluster 14 will likely be the last set of CAISO queued solar and wind projects with a potential to secure them.

[2] See IPE 2023, Track 3 Updated Final Proposal, March 2025, pg. 34.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

The California Community Choice Association (CalCCA) appreciates the opportunity to comment on the California Independent System Operator’s (CAISO’s) Interconnection Process Enhancements (IPE) 5.0 Scoping Document. IPE 2023 made transformative changes to the interconnection process to address the flood of projects seeking to interconnect to the CAISO system in support of the state’s policy goals. CalCCA appreciates the CAISO’s undertaking IPE 5.0 to continue to make incremental improvements to the interconnection process.

Specifically, CalCCA supports the CAISO’s commitment to revisiting the ability for operational energy-only (EO) projects to re-enter the interconnection process to be studied and to seek deliverability. While IPE 2023 policy prohibits EO projects in Cluster 15 and later from seeking a deliverability allocation, there are legitimate reasons why projects may pursue interconnection via the EO process, such as a willingness on the part of both developers and load-serving entities (LSEs) to contract for a period of time for EO deliveries.[1] At the same time, CalCCA understands and supports the CAISO’s intent of preventing developers from utilizing the EO pathway to circumvent a competitive deliverability allocation process. 

If a project enters the queue and comes online as EO, the project should be allowed to submit a new interconnection request and follow the intake and study process for obtaining deliverability. This approach could help expand and expedite opportunities for developers to finance and construct projects without a deliverability allocation while ensuring projects cannot circumvent the interconnection intake process, in which projects seeking deliverability and projects seeking EO are scored separately. Constructed and operational projects are more viable than earlier-stage projects under development and therefore may offer more affordable and timely pathways for additional deliverable supply. Especially at the current time, when there is a critical need for more affordable and deliverable capacity, these projects should be allowed to compete against other projects in the interconnection intake process and deliverability allocation process to contribute to the state’s resource adequacy (RA) requirements.

To avoid an EO resource from unduly benefitting from its EO status, the new interconnection queue request for deliverability should be evaluated using all the criteria that the CAISO has developed. In doing so, demonstration of a PPA should require the capacity element of the resource (i.e., RA) and not the existing EO contract that it had previously signed. The stakeholder process should also consider a reasonable limit on the number of times that an EO resource can seek deliverability, with a reasonable length of time between study requests, to ensure that the resources do not unnecessarily congest the queue and prevent more competitive resources from being studied.

In summary, projects that have achieved commercial operation as EO should be allowed to submit new interconnection requests, apply for deliverability allocation, and be scored along with all other projects seeking deliverability.

[1]               For example, the EO pathway has been used to get projects online in time to comply with grant timelines for grant-funded projects.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

The California Energy Storage Alliance (CESA) appreciates the opportunity to comment on the IPE 5.0 scoping memo.  In the scoping memo, CAISO identifies commitments made in the prior IPE initiatives.  For Track 3, CAISO has included "consideration of allowing long lead-time resources to defer their first attempt to seek deliverability."   However, in response to comments from Clearway, Invenergy, LSA and Terra-Gen, CAISO's committment was broader than described in the scoping memo.  CESA requests CAISO to confirm that IPE 5.0 will address all the issues raised by the stakeholders above.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

CAISO IPE 5.0 Scoping Comments

Clearway appreciates CAISO’s ongoing efforts to improve the interconnection process and help promote timely interconnection of new resources. Generally, Clearway believes that CAISO’s IPE 5.0 Scoping Document captures the items that CAISO previously committed to addressing in a subsequent IPE initiative. Clearway looks forward to reviewing and engaging in a subsequent IPE 5.0 Straw Proposal.

In addition to the items included in the IPE 5.0 Scoping Document, Clearway urges CAISO to take up a few additional items for consideration within IPE 5.0.

1. Enhancements to the intra-cluster prioritization process resulting from 2023 IPE Track 3
   1. Building on the success of the last IPE initiative, CAISO should consider expanding intra-cluster prioritization beyond RNU headroom. Intra-cluster prioritization enables projects to come online earlier instead of waiting for transmission upgrades. Clearway recommends considering an expansion to include DNU headroom that is dependent on long-lead-time upgrades. Like the RNU headroom allocation, CAISO could evaluate project “readiness” to allocate interim deliverability that projects can access prior to all deliverability upgrades being in-service, to ensure that all available deliverability can be used as soon as possible.
      
      With projects being asked to show commercial readiness early in the process while upgrade durations stretch farther out, getting contractable assurance of deliverability well in advance of COD is becoming important for timely offtake and financing of projects. While the interim deliverability associated with intra-cluster prioritization could be lost in subsequent years as earlier clustered projects come online, even this limited ability to achieve COD and access deliverability without waiting for delayed network upgrade  would be extremely valuable.
       
   2. CAISO should take measures to reduce the impact of LGIA execution delays in the existing RNU headroom intra-cluster prioritization process. Due to limited staffing, it is taking up to 10 months for PTOs to tender LGIAs. Clearway recommends adding a milestone to the process when an interconnection customer requests an LGIA. If the customer has requested an LGIA but has not yet been tendered, they should receive points in the RNU headroom evaluation.
2. Merchant zone to TPD zone transition framework

Clearway suggests that the CAISO consider a framework to optimize any TPD made available in a zone that is classified as a merchant zone during one interconnection cycle and becomes a TPD zone in a following cycle. Currently, if no merchant projects enter a merchant zone, any transmission capacity created by a TPP project in that zone will go unused for several years due to the lag in the interconnection process. To maximize the use of available TPD, Clearway encourages CAISO to create a pathway for projects that entered as EO projects in merchant zones to seek TPD if that zone later becomes a TPD zone, if there is capacity left unused after allocating TPD to any merchant projects. For example, if CAISO approves a policy-driven upgrade in the 2025-2026 TPP in a C15 merchant zone and creates TPD, then C15 projects that entered this zone as EO projects should be allowed to seek TPD in the 2027 TPD allocation cycle. Not doing so will leave this transmission capacity stranded from 2026 through 2029 until C16 projects successfully enter the queue and go through TPD allocation in 2029.

3. Pathway to EO resource buildout

CAISO should reconsider the ability for a project that fails to obtain TPD to convert to EO. Now that the IPE 2023 reforms have successfully reduced the size of the interconnection queue, it is essential that the queue maintains enough resources to support a reliable and clean system for LSEs. A recent filing by PG&E in the CPUC IRP docket shows that LSEs are facing a multi-GW need for new generating resources in the 2030 timeframe.[1]  It is essential that the interconnection queue has enough resources to meet near-term energy needs. Given that projects eligible to seek TPD entered the queue after qualifying through several “readiness” criteria and have committed significant development capital, a pathway for a project to convert to EO after failing to obtain TPD is a reasonable arrangement to ensure the queue meets the changing needs of load. To prevent non-viable projects from holding on to their queue positions, CAISO could develop Commercial Viability Criteria to limit the duration EO resources could stay in the queue.

4. Interconnection feasibility data availability prior to queue entry

Clearway commends CAISO for providing significant information prior to queue entry as part of C15. Building on that effort, CAISO should consider adding information about interconnection feasibility at substations. This information should include aspects such as substation access, known reliability limitations, and known long-lead upgrade concerns related to short-circuit duties or bus limitations. This will result in more educated and informed project entry into future queue clusters. CAISO could limit the scope of this work to only those substations that feature into CPUC’s portfolio busbar mapping. Most of these POIs have been evaluated for physical interconnection across several clusters by the PTOs. This information used to be provided to individual Interconnection Customers as part of project-specific cluster scoping meetings, which have now been eliminated. Clearway recommends that this database should be made available to stakeholders well in advance (~12 months) of queue entry.

5. MMA timelines

CAISO should add a simplification process for Material Modification Assessments (“MMAs”) into IPE 5.0. Clearway appreciates the changes made by CAISO to this process as part of IPE Track 3 and urges CAISO to explore further process efficiencies. While in 2024, the average time (in days) per completed study was 66 days, the MMA validation periods were much longer in our experience. Data validation adds weeks and sometimes months to the MMA process due to the administrative burden of multiple rounds of comments via Excel workbooks. Clearway urges CAISO to address the MMA validation process in this round of IPE and find ways to expedite the process.

[1] PG&E Opening Comments on Reliable and Clean Power Procurement Program Staff Proposal, filed July 15, 2025, in CPUC Docket 20-05-003.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

EDF power solutions (EDFps) appreciates the opportunity to comment on the Interconnection Process Enhancements (IPE) 5.0 Scoping Document. We commend CAISO for its ongoing efforts to refine the interconnection process. However, we impress upon the CAISO that this initiative will be fundamentally incomplete if it does not scope and address a significant structural barrier to new resource development: the commercial viability predicament created when projects are assigned Long Lead-Time Deliverability Network Upgrades (LLT DNUs).

The current CAISO-tariff, which includes FERC Order No. 2023 and IPE 2023 Track 2 reforms, creates a structural market barrier. The interconnection study process can assign an eight year or more DNU timeline to a commercially-viable project that requires only 2-4 years to construct. This disconnect between the grid planning timeline and the commercial development timeline renders projects un-contractable and un-financeable, forcing the withdrawal of needed resources and the developer forfeiting millions of dollars in financial security and creating a chilling effect on investment in California.

CAISO has previously acknowledged this fundamental misalignment. In its IPE 2023 Track 3 Final Proposal, the ISO noted that solutions would "need to extend beyond track 3" and that it looked forward to the CPUC’s Reliable and Clean Power Procurement Program (RCPPP) to "further inform the ISO’s efforts to better align planning, procurement, interconnection, and deliverability awards." This underscored an expectation that a robust, multi-year forward (beyond four years from COD) procurement program from the CPUC was the anticipated solution to the LLT DNU impasse.

That hope has not materialized. The record developed in the CPUC’s RCPPP proceeding makes it evident that a consensus on a long-term forward procurement framework that solves this issue is not forthcoming. With no external solution on the horizon, the responsibility to address this market failure returns squarely to CAISO. The problem is rooted in processes within CAISO’s exclusive jurisdiction: it is the CAISO study that identifies the upgrade, the CAISO tariff that dictates the milestone obligations, and the CAISO-administered market where the resulting commercial impasse occurs.

This flaw creates severe market inefficiencies. It strands development capital and prevents the most cost-effective resources from reaching commercial operation. We strongly urge CAISO to add the structural challenges, commercial viability impacts, and market efficiency consequences of LLT DNUs as a priority item within the IPE 5.0 scope. We look forward to working with CAISO and stakeholders to develop these critical solutions.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

Please see the attached comments from Invenergy.  We have provided them in both PDF and Word format.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

Please see the attached comments.  We have provided them in PDF format for posting, and in Word format for your ease in "cutting and pasting."

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

NextEra Energy Resources, LLC (NEER) appreciates CAISO’s ongoing efforts to streamline its interconnection, prioritization, and coordination processes. In addition to the items included in the IPE 5.0 Scoping Document, NEER requests CAISO consider expanding its scope to address the critical misalignment between transmission planning and generator interconnection processes that has created systematic Transmission Plan Deliverability (TPD) shortfalls in constrained areas. Specifically, CAISO should:

1. Resolve TPD Threshold Inconsistency: The threshold used to determine policy/reliability projects needed in transmission planning is lower than the threshold used to determine TPD availability in the interconnection process. This disparity has resulted in approved interconnection projects but insufficient TPD unlocking, particularly impacting the SDG&E region where limited TPD availability prevents resource integration across multiple clusters.

2. Implement Enhanced Sensitivity Analysis: CAISO should incorporate sensitivity scenarios in the Transmission Planning Process (TPP) that specifically address areas with severe deliverability constraints spanning multiple interconnection cycles, including the Desert Area Corridor in the SCE system and the SDG&E 230 kV network. These scenarios must trigger the same constraints identified in generator interconnection studies and ensure timely transmission solutions are developed and Board-approved to prevent chronic TPD deficits.

3. Strengthen TPP-Interconnection Coordination: CAISO should establish formal mechanisms to monitor TPD shortfalls by geographic region and implement expedited transmission planning processes when systematic deliverability deficits are identified, ensuring transmission infrastructure development keeps pace with generator interconnection approvals.

These enhancements are essential to resolve the persistent deliverability challenges that have prevented renewable resource integration in California's most constrained transmission areas.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

NCPA appreciates CAISO’s continued efforts to improve its interconnection process and procedures. While the 2023 Initiative was an important step in the right direction, there is still work to do and a number of issues that were flagged for further consideration.

NCPA believes the IPE 5.0 Scoping Document includes a comprehensive list of topics for this new stakeholder initiative, although particular elements may be further refined or adjusted as the stakeholder process progresses. While NCPA does not comment on each element at this scoping stage, we highlight certain important topics for CAISO to consider. For example, the Scoping Document lists “Reserve TPD for long lead-time resources to ensure transmission availability and transparency” as an item stakeholders have suggested for consideration. It is not clear from the Scoping Document what changes to the existing process for reserving TPD for certain long lead-time resources that fulfill specific public policy requirements may be contemplated under this item, but it is important that CAISO provide more detail and transparency around TPD reserved for long lead-time resources in future transmission planning and interconnection cycles. NCPA requests that IPE 5.0 include consideration of how this information will be provided, such as identifying how much TPD is being reserved for such purpose down to the specific busbar. NCPA also requests CAISO lay out the circumstances under which the reserved capacity will be released from reservation such as projects missing milestones.

NCPA particularly supports the inclusion of “Revisit the cap on full allocation election to small LSEs and revise as appropriate” in the scoping document. This cap was a late addition to CAISO’s filing with FERC and undermines the purpose of the Full Allocation Election—which is to allow small LSEs a reasonable ability to express commercial interest in resources. Because of the relatively large size of most new generation compared to the capacity of small LSEs, a cap of 150% of the LSE’s capacity allocation could prevent small LSEs from reflecting full interest in new generation. Small LSEs often require intermittent procurement of large projects (as opposed to more frequent acquisition of smaller projects), and it is important that CAISO’s scoring rules align with this reality so that they accurately indicate project viability.

Finally, while NCPA supports CAISO monitoring the issue of the “LSE allocation process,” NCPA believes this process is working well. In order to participate in this process, LSEs must adopt and use publicly-available criteria and provide certain other information. LSEs are experienced in administering competitive solicitation processes, and there is no need for CAISO to micromanage how LSEs allocate commercial interest points. Indeed, doing so risks undermining the purpose of commercial interest points—reflecting the actual interests of LSEs in order to indicate project viability.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

PG&E appreciates this opportunity to comment on the Scoping Document for IPE 5.0. 

Through the successful implementation of reforms from previous IPE iterations, CAISO has achieved a significant reduction of volume in the queue for Cluster 15, focusing study attention on the most viable and shovel ready project applications.  PG&E believes, as a next step in the reform process, CAISO should use this IPE to consider the disposition of older applications, from Cluster 14 and prior, including establishing a process for determination of which applications may rightly be removed from the queue due to time limits and changing circumstances.

• Time-in-queue limits: One of the issues identified in the IPE 5.0 process is “Managing the impact of the accumulation of stagnant projects in the queue”. The final proposal for the 2023 IPE Track 2 included a recommendation to implement time-in-queue limits for all projects submitted prior to the QC15 cycle. However, this recommendation was not incorporated into the tariff language for the 2023 IPE implementation. PG&E respectfully requests that this proposal be adopted or, alternatively, that CAISO provide a rationale for its exclusion.
   
• Eliminating projects from the queue: EO projects that have met all the posting requirements and continue to meet development milestones but have not received TPD after 3 years could still be allowed to remain in the queue in order to seek TPD after coming online. However, there should be safeguards in place to make sure such projects come online when they originally requested and are removed from the queue if they remain there beyond 7 years.
   
• Treatment of TPP Projects: For Cluster 15, Participating Transmission Owners (PTOs) were instructed to include the approved 2024–2025 Transmission Planning Process (TPP) projects in the base case assumptions. These projects have not yet undergone study through the TPP process. Consequently, any network upgrades potentially triggered by these TPP projects may be incorrectly assigned to Cluster 15 projects. These upgrades would later be removed if the TPP study identifies them as associated with the proposed TPP projects. However, the differences between the TPP and GIDAP base case assumptions can result in misattribution of upgrade responsibility. This highlights the need to revise the methodology used to study the grid impacts of TPP projects.
   

• Long-lead time projects: PG&E agrees that more process is needed around the reservation of TPD for long-lead time projects, including when TPD may be reserved when a policy-specific upgrade has not been triggered.  If these long-lead time projects are enabled by reliability upgrades or other projects dropping out of the queue, such TPD should also be reserved, with a process for releasing the TPD.
   
• Data transparency: The CAISO should explore simple fixes to ease data access. For example, addition of a column that shows if TPD is available by POI, versus just showing the constraints, would make digesting various versions of the interconnection constraints file easier. Additionally, PG&E suggests that contact information be made available for all projects in the queue, for example, to ensure notification of interested parties for LSE procurement RFIs.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

SDG&E Comments Regarding IPE 5.0

1. Deliverability-Seeking WDAT Treatment: SDG&E agrees with CAISO’s position outlined in the Scoping Document regarding WDATs seeking deliverability. SDG&E has long maintained that treatment of WDAT projects seeking deliverability was not fully addressed in the adopted IPE enhancements to date. Incorporation of WDATs seeking deliverability into the intake scoring process and the 150% study cap, as highlighted in the scoping document, will ensure consistent treatment amongst all types of resources. SDG&E encourages CAISO to maintain this position through implementation. As a secondary note, it may be prudent for CAISO to clarify that only WDATs seeking deliverability are in the scope of this proposal.
2. Queue Management requirements from IPE Track 2: SDG&E encourages CAISO to implement the requirements in the Queue Management section of IPE Track 2 (Section 3 of the Final Proposal document) that were approved by the Board of Governors. The provisions relating to Time-in-Queue, Shared Network Upgrades, First Notice to Proceed, among others, are all significant enablers to meeting the IPE’s goals of a streamlined process and more accurate study results.
3. Initial Commercial Readiness Deposit Process: SDG&E proposes a more consistent approach to collecting initial Commercial Readiness Deposits (CRD) that are more practical and customer-friendly than the options available today. To this end, SDG&E proposes the following options:
   1. CAISO collects CRDs: This is SDG&E’s preferred option, as it would provide the most seamless and consistent process between projects. This process could be similar to CAISO’s current role in collecting study deposits.
   2. Shifting the CRD Collection Timeline: Alternatively, SDG&E hopes CAISO will consider shifting CRD collection to after the initial application completeness review, but prior to the start of the study. If adopted, this approach would help relieve the current time constraints around reviewing financial security documents during the initial application window.
4. LGIA execution after TPD allocation: SDG&E cautions against imposing unnecessary administrative strain given the hard deadlines involved.  An example is whether the 30-day Tender timeline in Appendix KK might be unduly encroached upon while TPD allocation results are finalized. SDG&E encourages CAISO to consider and remedy any such examples that may cause unnecessary administrative strain.
5. Cap on Full Allocation to Small LSEs: SDG&E supports CAISO revisiting the cap for small LSEs exercising their ability to fully allocate their points to a single project. A modification that could be considered would be to change the election cap for small LSEs lacking sufficient points to match the capacity of that project, from “one hundred fifty percent (150%) of the Load Serving Entity’s most recent coincident peak demand forecast from the California Energy Commission”, to a maximum of that cap or the delta between MWs eminently retiring and MWs under contract yet to achieve COD. This increased flexibility would allow small LSEs to secure procurement needs (including resource retirement) via full allocation of the single project; while ensuring they are not indicating commercial interest beyond what is prudent.

1. Please provide your organization's comments on any other items that should be considered for IPE 5.0.

SCE appreciates the CAISO’s issuance of the IPE 5.0 Scoping Document to address commitments made during IPE 2023. SCE is pleased with the inclusion in the Scoping Document of “incorporation of WDAT projects into the intake scoring process and the 150% study limit accounting”, as part of the IPE 2023 Track 2 commitments to revisit elements of the interconnection request intake process.  In addition to the scoring process and the 150% study limit issue, the IPE 5.0 should include the applicability of other IPE elements which implicate the CAISO to WDATs (e.g., application of shared network upgrade requirements in GIDAP Section 11.3.2.6).