California Unveils $6.7B Transmission Upgrade Plan
The California Independent System Operator (CAISO) Board of Governors has approved its 2025–2026 Transmission Plan, outlining 38 infrastructure projects with an estimated full-buildout cost of $6.7 billion.
The updated plan reflects a slight reduction from an earlier $7 billion draft, following revised cost inputs from transmission owners. According to the report, more than half of the proposed projects and associated costs are driven by projected electricity demand growth across California.
The California Energy Commission (CEC) estimates that statewide electricity demand will increase by 15 gigawatts (GW) by 2035 and 20 GW by 2040, primarily due to electrification of buildings and transportation, industrial expansion, and large energy users such as data centers.
The plan includes 12 reconductoring projects designed to increase transmission capacity using existing corridors, including three projects utilizing advanced conductors classified as grid-enhancing technologies (GETs). It also identifies the need for a potential new 500-kilovolt transmission line along the Path 15 corridor, which will undergo further evaluation in the next planning cycle.
One previously approved project, the Serrano-Del Amo-Mesa 500 kV reinforcement in the Los Angeles Basin, was cancelled after updated cost analysis deemed it no longer cost-effective. The CAISO indicated that reliability needs in the area will instead be addressed through smaller upgrades and expanded energy storage.
The plan also supports long-term renewable integration, including infrastructure to enable 45 GW of solar, 8 GW of wind in Tehachapi, more than 2 GW of geothermal, and over 10 GW of wind imports from neighboring states. Offshore wind development capacity of more than 4.5 GW along California’s coast is also included.
Source: environmentenergyleader.com
