Powering Strong Communities

California ISO Sees Need For $30 Billion Investment in Transmission Resources

California will need as much as a $30.5 billion investment in its bulk transmission system to meet the needs of the state’s clean energy goals, according to the California Independent System Operator (CAISO).

In a draft of its first-ever 20-year transmission outlook, CAISO detailed a need for $10.74 billion for upgrades to existing transmission lines and substations in its footprint, $8.11 billion for transmission lines to integrate offshore wind resources, and $11.65 billion for power lines to integrate out-of-state wind resources.

The investments represent “significant investments,” some of which will require lead times of at least eight to 10 years, the authors of the paper said.

The need is being driven by increased customer demand for clean energy, the continuing electrification of transportation sector and other industries, and by the requirements of Senate Bill (SB) 100 that requires the state to obtain 100 percent of its retail electricity from non-carbon-producing sources by 2045.

CAISO’s starting point for the study was a high electrification peak load projection under SB 100 of 82,364 megawatts (MW) in 2040, representing a 28.5 percent increase from the California Energy Commission’s (CEC) Integrated Energy Policy Report 2020 load forecast of 64,076 MW in 2031.

CAISO then identified the resources that would be needed to meet that demand while taking into account a projected reduction of 15,000 MW of natural gas-fired generation.

CAISO’s analysis called for 37 gigawatts (GW) of battery energy storage, 4 GW of long-duration storage, over 53 GW of utility scale solar, over 2 GW of geothermal generation, and over 24 GW of wind generation, split between out-of-state and in-state wind resources with the bulk of the in-state resources consisting of offshore wind.

The 20-Year Outlook provides a baseline to establish expectations for longer-term planning, CAISO said, adding that resource planning and procurement decisions will likely evolve over the years ahead as assumptions used to establish the baseline analysis change.

CAISO expects to conduct additional stakeholder dialogue through 2022 about the next steps, as well as the long-term architecture, set out in its draft outlook.

CAISO created the 20-year transmission outlook in collaboration with the California Public Utilities Commission (CPUC) and the CEC and said it would continue to coordinate with the CEC and the CPUC, which takes a lead role in developing resource forecasts for the 10-year planning horizon.