The NYISO Transmission Planning Advisory Subcommittee (TPAS) discussed stakeholder comments on possible improvements to the cluster study process and the system deliverability test process in response to presentations given in December 2025.
Stakeholders including the Alliance for Clean Energy New York and Granite Source Power asked for improvements to the pre-application process and increased training for interconnection customers. ACE NY asked for clarification to NYISO’s definition of “physical infeasibility” and for more information to be given to interconnection customers once a project is deemed infeasible. The organization asked NYISO to require that transmission owners provide interconnection customers with the studies that determined whether a project is infeasible.
GSP asked for greater standardization between transmission owners regarding site plan requirements and agreed with ACE NY that the physical infeasibility screening needed clarification.
RWE Clean Energy asked for a fast-track interconnection process for projects addressing reliability issues. Invenergy asked for an expedited capacity resource interconnection study mechanism for interconnection of co-located energy storage resources.
NYISO staff said in an earlier presentation that managing the reliability impact of the 70 GW of new generation in the queue requires numerous upgrades. The ISO previously stated that the first cluster study — the “transition cluster study” — had posed challenges to staff including many iterations of deficiency reviews due to inconsistent and inaccurate interconnection requests. The deficiencies led to withdrawals, which led to dispute resolution processes and model updates. The large volume of projects in the cluster study also poses significant challenges for validating interconnection requests and performing required evaluations on time.
The ISO presentation indicated it also wanted to pursue increased training for interconnection customers, simplify paperwork for interconnection requests and clarify the deficiency process.
Deliverability Test Recommendations
The deliverability test is a critical part of the interconnection process, which helps determine if a project is deliverable at its requested “capacity resource integration service” level, measured in megawatts. If a project cannot deliver, NYISO looks for system deliverability upgrades — upgrades to the grid — that would allow the project to function at its requested megawatt value and determines costs to the resource.
NYISO identified challenges with the deliverability test, particularly the establishment of a base case and unforced capacity factor assumptions in late 2025. Stakeholders submitted comments for discussion at the Jan. 5 TPAS meeting.
ACE NY asked for clarification of the implementation schedule of the updates to the deliverability test, citing possible confusion over when the new test would be in place. It added there was a risk of confusion with system deliverability upgrade cost estimates and asked NYISO to issue two separate ones based on the proposed new rules and the old rules.
The Market Monitoring Unit issued a memorandum in response to NYISO’s move to reform the deliverability test. The MMU has long argued that the current test penalizes new resources and is poorly suited to new technologies seeking to interconnect, specifically storage resources. The MMU asked NYISO to consider creating more capacity zones, reflect import bottlenecks in capacity accreditation factors and remove “highways deliverability test” from the cluster study.
Tony Abate, representing the New York Power Authority, said he didn’t think the MMU’s suggestions were possible to implement while the ISO is trying to reform the cluster study process. He said he appreciated the MMU’s “aspirational” stance but didn’t think new capacity zones could be delivered simultaneously with the other reforms.
Thinh Nguyen, senior manager of interconnection projects for NYISO, said the ISO is still in the process of reviewing comments and would get back to stakeholders at a future meeting.
In Other Business
TPAS heard system impact study scopes for two data center projects, both being developed by Turn Management in Herkimer County. Collectively, the two data center loads would be 500 MW on the same site. TPAS did not issue any objections and allowed both SIS scopes to move forward for Operating Committee consideration.
