The California ISO 2025-2026 transmission planning cycle involves key stakeholder activities from 2025 through early 2026. Each year, the ISO conducts its transmission planning process to identify potential system limitations as well as opportunities for system reinforcements that improve reliability and efficiency. The transmission planning process core product is the ISO Transmission Plan, which provides an evaluation of the ISO control grid, examines conventional grid reliability requirements and projects, summarizes key collaborative activities and provides details on key study areas and associated findings.
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Dec 30, 2024 30-day comment period begins
Feb 20, 2025* Draft study plan posting Feb 26, 2025* Hybrid stakeholder meeting Mar 12, 2025* Comments due Mar 31, 2025* Final study plan posting Aug 15, 2025* Preliminary reliability study results & mitigation solutions posting Aug 30, 2025* Scenario base cases posting Sep 24-25, 2025* Hybrid stakeholder meeting Oct 9, 2025* Comments due Oct 31, 2025* Final reliability study results posting Nov 2025* Preliminary assessment of policy & economic planning studies posting Nov 2025* Hybrid stakeholder meeting Dec 2025* Comments due Mar 31, 2026* Draft transmission plan posting Apr 15, 2026* Hybrid stakeholder meeting May 2026* Board of Governors meeting May 2026* Final board-approved transmission plan posting |
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Stakeholder comment period for 2025-2026 unified planning assumptions and study plan is Dec 30, 2024 through Jan 30, 2025. See the notice for more information.
Link to Dec 30 notice 12/30/2024
Letter - Data Request and Invitation to 2025-2026 Transmission Planning Process - Dec 30, 2024 12/30/2024
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