California ISO’s 20-Year Transmission Outlook

• CAISO's draft transmission outlook expects California to need 120.8 GW power generation capacity by 2045 to achieve a carbon-free grid
• It needs to then plan for $30.5 billion worth of transmission development to accommodate this capacity which includes over 53 GW utility scale solar
• It has also released a draft 10-year 2021-2022 transmission plan expecting an addition of 2.7 GW annually, which may be increased to over 4 GW annually from next year

The California Independent System Operator (CAISO) expects the western US state to prepare its grid transmission infrastructure to accommodate 120.8 GW of power generation capacity comprising over 53 GW of utility scale solar, for it to become a carbon-free grid by 2045.

Remaining electricity generation capacity as stated in CAISO's draft 20-Year Transmission Outlook counts for it to need more than 24 GW of wind energy generation, over 2 GW of geothermal, 37 GW of battery energy storage and 4 GW of long-duration storage. Transmission development for all of this capacity is expected to cost $30.5 billion.

CAISO created the draft in collaboration with the California Public Utilities Commission (CPUC) and the California Energy Commission (CEC) to explore long term grid requirements and options to meet the state's target to meet all its electricity requirements by 2045 with renewable and zero-carbon resources.

"Primary drivers of the 20-year roadmap are the state's goals of getting all electricity from carbon-free resources by 2045, and further electrifying the transportation, industrial, and residential sectors," states CAISO.

The operator has also introduced the draft of its customary 10-year transmission planning process 2021-2022 Transmission Plan, covering the period from 2021-2031. It envisages addition of around 2.7 GW power generation capacity annually and 'current drafts being proposed for next year's plan call for over 4 GW per year.

"The 2021-2022 10-year plan recommends approval of $2.9 billion in projects to improve reliability and access to renewable generation in the next decade," it added.

CAISO will hold a stakeholder call on both documents for February 7, 2022, and will accept comments on both the reports till February 21, 2022.