Grid Horizon
From CAISO’s new intake scoring to MISO’s first SUGAR-based study window, major interconnection shifts are underway across the U.S. This month, we’re tracking critical updates across PJM, NYISO, ISO-NE, CAISO, MISO, and TVA — including new cluster-based reforms, study tool transitions, and upcoming decision points. We also preview how Nira is helping customers stay ahead with early deliverability insights, automated scenario modeling, and updated regional tools. Whether you’re in the queue or prospecting your next site, now is the time to get aligned with the latest changes.
ISO-NE Transitioning to Cluster Process Under FERC Order 2023
ISO-NE is transitioning to a new cluster-based interconnection process in compliance with FERC Order Nos. 2023 and 2023-A. Below are key updates to be aware of as we approach the October 10, 2025 deadline.
Key milestones:
🗓 August 11, 2025: ISO-NE begins reviewing Transitional Cluster Study (TCS) packages for completeness
🗓 October 10, 2025: Final deadline to submit a fully executed TCS Agreement package, including: Site control documentation (100% site control in the IC’s name) Required technical data Study and Commercial Readiness Deposits Interconnection service selection (NRIS/CNRIS or NIIS/CNIIS)
After October 10, ISO-NE will begin evaluating technical data and issuing deficiency notices, with 15 business days to cure any issues.
Additional considerations:
Projects that withdraw after entering TCS could face a Transitional Withdrawal Penalty (up to 9x study costs, capped at the Commercial Readiness Deposit).
If a project elects to automatically option from CNRIS to NRIS due to thermal constraints in the TCS Agreement, this will be enforced and cannot be reversed
A new version of Planning Procedure 5-6 (PP5-6), including stricter model test requirements, goes into effect after the October 11 start date.
📌 Why it matters: This is a make-or-break window for projects in ISO-NE. Projects should confirm data completeness, finalize site control, and get their full TCS package submitted by October 10 to avoid costly delays — or the need to restart in the next cluster. Nira will continue to closely monitor this update and how it can impact our customers.
MISO Update: SUGAR Officially in Use for DPP-2022
MISO’s 2022 Phase 1 Decision Point window is now open, closing July 29. This is the first active cycle using SUGAR as the official study tool, replacing TARA.
📌 Why this matters: After multiple rounds of revisions, MISO has finalized its System Impact Study (SIS) report and study models. With SUGAR now live, developers must adapt quickly to changes in model behavior, upgrade assumptions, and result interpretation.
Looking Ahead: DPP-2023 Launch Pending FERC Ruling
MISO expects to launch the DPP-2023 cycle on August 9, but this is contingent on a key FERC ruling due August 3 (Docket ER25-2418-000). The decision will determine whether JTIQ upgrades are included in DPP-2023 starting models.
What to expect:
🗓 August 5, 2025: MISO will post prescreen results for DPP-2023
Developers have 14 days to decide whether to stay in or withdraw
📌 Why this matters: The inclusion of JTIQ upgrades could substantially affect upgrade costs and project competitiveness. Understanding model changes early is critical.
✅ How Nira helps:
Our MISO platform is already updated for SUGAR and will support:
SUGAR vs. TARA comparison
Dropoff and withdrawal scenario testing
Upgrade cost forecasting under both base model conditions (with and without JTIQ)
Let us know if you want help navigating this pivotal decision window.
TVA Moves to Cluster Studies with New TARA Module
PowerGem and TVA have completed development of a cluster-based interconnection automation tool. This puts TVA on a similar path to MISO, SPP, and PJM — moving away from serial studies and toward a more scalable cluster approach.
📌 Why this matters: The inclusion of JTIQ upgrades could substantially affect upgrade costs and project competitiveness. Understanding model changes early is critical.
NYISO: Transition Cluster Delayed, Nira’s Deliverability Preview Coming Soon
NYISO has officially delayed Decision Period 2 for the Transition Cluster (C24) by 60 days, citing continued delays in National Grid’s Phase 1 study reports.
What’s changed:
Of the 89 National Grid projects under study, 65 now face report delays: 26 draft reports expected by September 1, 2025 39 draft reports expected by October 1, 2025
The full Transition Cluster timeline has been pushed back, including the start of the next cluster’s application window.
📌 Why it matters:
Phase 1 reports do not include deliverability results, making it difficult to assess project competitiveness before Phase 2.
For developers, this delay creates a valuable window to evaluate risk and readiness ahead of key financial commitments.
✅ How Nira is supporting TC developers:
Nira’s In-Queue NYISO module will roll out in three phases to help developers prepare:
Byway Deliverability Results Preview
Drop-off Scenario Analysis
Highway Deliverability Results
If you’re participating in TC24 and need help navigating deliverability ahead of Decision Period 2, reach out — our team is here to support.
PJM Update: New Reform Cycle Underway, RRI Projects Included
What’s happening:
Transition Cycle 1 is in Phase 3 — the final stage for AE1–AG1 projects under the legacy study process.
Transition Cycle 2 is officially underway — the first cycle using PJM’s 2022 Reform Process.
TC2 includes 51 projects under the Reliability Resource Initiative (RRI) — a one-time inclusion of generation resources PJM fast-tracked to address near-term reliability needs.
📌 Why it matters:
The inclusion of RRI projects in TC2 was controversial, with many developers pushing back before FERC approved it.
Developers are still adjusting to PJM’s reformed process, which introduces complex cost allocation rules and new study phases.
✅ How Nira is supporting PJM developers:
Our In-Queue PJM product tracks all procedural changes and integrates PJM’s evolving cost allocation methodologies. We’ve supported developers across both TC1 and TC2 by helping them:
Model complex scenarios under new queue rules
Understand the impact of RRI inclusion on upgrade triggers
Prepare for the full queue reform rollout in 2026
If you're navigating PJM’s new cycles or the evolving queue structure, our team can help make sense of the process and plan accordingly.
CAISO: Cluster 15 Intake Results Shape What’s Ahead for Cluster 16
CAISO’s new scoring-based intake process for Cluster 15 has significantly reduced queue volume — and shaped expectations for how Cluster 16 will be evaluated.
What happened:
CAISO’s intake scoring ranked projects by commercial interest, viability, and system need.
For each transmission constraint, projects were accepted into the queue in score order until the 150% Transmission Plan Deliverability (TPD) cap for that constraint was reached.
The queue dropped from 541 initial submissions (2023) to 255 resubmissions (2025), with only 177 accepted projects after intake scoring, a 31% reduction.
CAISO has indicated they’re satisfied with the outcome and do not currently plan to adjust scoring criteria for Cluster 16.
Project scoring details (e.g. zonal averages) will remain confidential under CAISO’s tariff, unless stakeholders pursue a change.
📌 Why it matters:
This intake process fundamentally changes how to successfully enter the queue in CAISO. It’s no longer about just submitting — it’s about siting strategically to maximize your project’s score and clear the constraint-specific TPD threshold.
✅ How Nira is helping developers prepare for Cluster 16:
This quarter, Nira is launching a new CAISO prospecting tool that gives developers an early look into TPD availability at Points of Interconnection (POIs). With this data, developers can site projects where they’re most likely to be accepted under the new Cluster 16 scoring process.
If you’re planning for Cluster 16, now’s the time to get your siting strategy right — and we’re building the tools to help you do it.
