The California Independent System Operator (ISO) Board of Governors has approved the ISO’s 2025-2026 Transmission Plan, recommending 38 infrastructure projects to accommodate rising electricity demand – and support the state’s energy goals. In addition to continuing to expand access to lower-cost resources, the plan prioritizes transmission needed to serve growing customer demand reliably and economically.

More than half the projects – and more than half the $6.7 billion estimated cost – are driven by forecasted load growth. Most of the remaining projects are needed to access resource development basins identified by the California Public Utilities Commission (CPUC) and to serve load and meet state reliability and greenhouse gas reduction goals.

Initial draft estimates released in April projected $7 billion in upgrades but updated cost assumptions have reduced the total projected costs to $6.7 billion at full buildout over the next decade.

Detailing on their views, Neil Millar, the ISO’s Vice President, Transmission Planning and Infrastructure Development, said, “We are constantly striving to find ways to meet system needs in the most affordable way possible. This year’s plan does that in a number of different ways while also making sure we have the right infrastructure in place to accommodate all of the new resources that are being added to the system.”