Image for illustrative purposes

The California Independent System Operator (CAISO) Board of Governors has approved the organization’s 2025–2026 transmission plan, authorizing 38 infrastructure projects with an estimated total cost of $6.7 billion to expand and reinforce California’s electricity grid over the next decade.

The approved plan reflects a slight reduction from an initial $7 billion estimate following updated cost inputs from transmission developers. According to CAISO, more than half of the projects and associated costs are driven by projected increases in electricity demand.

The California Energy Commission (CEC) forecasts that statewide electricity demand will rise by 15 gigawatts (GW) by 2035 and 20 GW by 2040, driven by electrification of buildings and transport, industrial growth, and large-scale loads including data centers.

The plan includes 12 reconductoring projects aimed at increasing capacity on existing transmission lines, including several using advanced conductors classified as grid-enhancing technologies. It also identifies the need for a new 500-kilovolt transmission line along the Path 15 corridor to reduce congestion, subject to further engineering review in future planning cycles.

One previously approved project, the Serrano–Del Amo–Mesa 500 kV transmission reinforcement in the Los Angeles Basin, has been removed from the plan after updated cost assessments determined it was no longer the most cost-effective option. CAISO noted that local reliability needs will instead be addressed through smaller upgrades and energy storage deployment.

The plan also supports long-term renewable energy integration, enabling transmission access for up to 45 GW of solar capacity, 8 GW of in-state wind, more than 2 GW of geothermal energy, over 10 GW of imported wind, and offshore wind development along California’s coast.

Source: environmentenergyleader.com