CAISO has entered a new chapter in its interconnection process with the launch of the 2025 Interconnection Prioritization Process, effective June 25, 2025. Approved by FERC as part of Track 3 of the Interconnection Process Enhancements, this reform is one of the most consequential changes to California’s grid planning framework in years.
Why is this important? Because California’s interconnection queue; a lineup of renewable and storage projects awaiting approval to connect to the grid, has become one of the most congested in the country. With gigawatts of projects competing for limited transmission access, the system has often favored volume over viability, leading to delays, attrition, and uncertainty for developers and investors alike.
By introducing a structured prioritization process, CAISO is shifting the focus toward readiness, policy alignment, and transmission feasibility. Projects that demonstrate real progress in permitting, site control, and financing, and that advance California’s clean energy and decarbonization mandates, will now have a clearer, faster path forward. This approach represents not only an administrative fix but also a strategic effort to align California’s grid with its ambitious climate and reliability goals.
CAISO’s Clean Energy Goals; Aim with the New Process
With more than 400 GW of projects sitting in U.S. interconnection queues, California’s reforms aim to bring order to a backlog that has long slowed renewable development. The 2025 prioritization process directly addresses:
- Transmission Bottlenecks – Aligning projects with available or planned transmission capacity.
- Project Readiness – Requiring stronger evidence of site control, permitting progress, and financing.
- Policy Alignment – Giving preference to projects supporting state decarbonization, reliability, and RPS goals.
- Transparency – Publishing eligibility lists, study plans, and results on fixed timelines.
Key Milestones
- June 25, 2025: Tariff revisions effective.
- May 1 & July 15, 2025: Draft and final eligibility lists of reliability network upgrades published.
- August 1 & August 15, 2025: Developer affidavits and scoring submissions due.
- October 1, 2025: Project rankings released to Participating Transmission Owners.
- December 2025: Developers notified of rankings and advancement status.
- January 2026: Final study reports published.
Interconnection Reform Implications for Developers & Investors
For developers, the new framework enforces earlier accountability: only the most credible and well-prepared projects will advance. For investors, it provides a clearer lens on which projects are likely to survive the queue, reducing capital risk and uncertainty.
Looking Ahead: The Future for CAISO’s Interconnection Queue
Looking forward, the 2025 interconnection reforms are more than a policy update, they are a litmus test for California’s energy future. If successful, this framework could serve as a model for other ISOs and RTOs struggling with backlogged interconnection queues and transmission bottlenecks. For developers, the message is clear: early preparation and strong documentation will separate viable projects from speculative ones. For investors, these changes create a more transparent environment, helping them allocate capital toward projects that stand the best chance of reaching commercial operation.
At the same time, the stakes are high. California’s ability to meet its renewable portfolio standards, integrate battery storage, and ensure long-term reliability depends heavily on how efficiently this new process functions. Delays in interconnection ripple outward, affecting everything from utility procurement to state climate reporting.
That’s where ZEG comes in. Our team helps stakeholders understand the regulatory nuances, transmission impacts, and project viability factors that define success in CAISO’s evolving interconnection landscape. Whether you’re a renewable developer aiming to advance your project in the queue, a utility aligning resources with future capacity, or an investor seeking clarity in a complex market, we provide the expertise to navigate these reforms with confidence. Contact us and get started today!
For details on CAISO’s challenges and reforms, explore our article on the topic, Inside CAISO’s Interconnection Queue: Challenges and Reforms Ahead.
Click here to learn more about CAISO and its’ interconnection reforms.
