CAISO approves US$2.9bn of transmission projects to enhance reliability

Facebook
Twitter
LinkedIn
Reddit
Email
EDF’s Desert Harvest solar project in California. Image: EDF Renewables North America.

California’s grid operator has green-lighted a new plan to upgrade and expand the state’s transmission system as more renewables come online amid increased electrification.

Approved by the California Independent System Operator (CAISO) last week, the 2021-2022 plan identified 23 projects, estimated to cost $2.9 billion, for system expansions, upgrades and reinforcements needed for reliability and to meet the state’s clean-energy targets for the next ten years.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

With California aiming to transition to a carbon-free power sector by 2045, the need for new generation over the next ten years has escalated rapidly, driving an accelerated pace for new transmission development in this and future planning cycles, CAISO said.

While last year’s plan was based on projections that about 1GW of new resources would be needed annually over the following ten years, the new roadmap is based on adding about 2.7GW per annum. The next plan, meanwhile, is currently projected to assume a requirement of more than 4GW of new resources per year.

Faster resource development over the next decade is driven by factors such as the escalating need to decarbonise the electricity grid because of “emerging climate change impacts” and the expected electrification of transportation and other carbon-emitting industries, CAISO said.

In addition, more resources will be needed in California because of concerns regarding reduced access to opportunity imports as neighbouring systems also decarbonise and greater than anticipated impacts of peak loads shifting to later in the day when solar resources are unavailable.

These resource requirements, on the path to total grid decarbonisation, will demand increased volumes of solar PV and battery storage alongside greater roles for geothermal, new out-of-state renewables and offshore wind generation, according to CAISO.

The grid operator said the transmission systems will “need to be expanded, upgraded and reinforced to access and integrate these resources, as well accommodate the expected resurgence in electricity consumption as transportation and other industries electrify to reduce their carbon impact”.

Publication of the latest strategy comes after the California Public Utilities Commission approved plans last month that will see the state add almost 19GW of utility-scale solar and 15GW of battery energy storage systems by 2032.

Annual solar PV additions in California declined to 3,640MW last year, according to new research from the Solar Energy Industries Association and Wood Mackenzie, which revealed that Texas, with more than 6GW, was the top-ranked state for solar deployment in 2021, thanks to a strong year for its utility-scale segment.

Read Next

October 6, 2025
An expert panel has identified a series of grid failures that led to April's unprecedented power outage in Spain and Portugal, ruling out renewables as the leading cause.
Premium
September 26, 2025
CALSSA's Kevin Luo spoke with PV Tech Premium exclusively on the association’s complaint about slow approval practices in California.
September 26, 2025
Global grids have failed to keep pace with renewable energy technologies and have become the “bottleneck of the energy transition”, according to a new policy report from the Global Solar Council (GSC).
Premium
September 24, 2025
European geopolitical tensions have exploited weaknesses in grid systems, leaving 55% of Europe’s grids vulnerable, according to Ember.
September 23, 2025
Australia’s NEM set a new instantaneous renewables share record of 78.6% on 22 September, surpassing the previous day's record of 77.9%.
September 17, 2025
The California State Legislature has passed two bills that aim to reduce energy prices in the state, AB 825 and SB 302.

Subscribe to Newsletter

Upcoming Events

Solar Media Events
October 7, 2025
Manila, Philippines
Solar Media Events
October 7, 2025
San Francisco Bay Area, USA
Solar Media Events
October 21, 2025
New York, USA
Solar Media Events
November 25, 2025
Warsaw, Poland