California Grid Operator Releases 20-Year Transmission Plan to Meet Clean Energy Goals

The California Independent System Operator Corp. on Feb. 1 released a 20-year transmission outlook that discusses long-term infrastructure requirements to reach the state’s target of generating 100 percent electricity from carbon-neutral sources by 2045. The draft plan is based on the assumption that about 120 gigawatts will have to be added to the grid by 2040 to meet the growing demand for electricity. The transmission development required for upgrades to the existing system, as well as offshore wind and out-of-state wind integration, is estimated to cost about $30.5 billion.

The forward-looking transmission planning and coordination will help define California’s future grid architecture and better transmission infrastructure, resource procurement, and interconnection queuing. The operator has collaborated with California Energy Commission and Public Utilities Commission to assess various power generation resources and transmission substitutes.

In the 20-year outlook, the agency considered the resources required to meet 2045 goals and formed a starting point scenario, which accounted for the forecasted 2040 peak load, deducted the contribution of forecasted behind-the-meter resources, and then included a projected reduction of 15,000 megawatts of natural gas-fired generation. The scenario resulted in about 120 gigawatts of additional generation capacity added to the grid by 2040, including 37 gigawatts of battery storage, 4 gigawatts of long-duration storage, around 53 gigawatts of utility-scale solar, 24 gigawatts of wind generation, and over 2 gigawatts of geothermal energy. The resulting outcome calls for significant transmission infrastructure to upgrade to the existing system.

The plan is intended to help speed up key decisions about power resources addition and transmission, and guide interconnections of new resources. Since such transmission projects are expected to take between eight and ten years to commission, the draft will help multiple stakeholders together to prioritize and identify the best solution. A total of 79 clean-energy projects were connected to the California grid in 2021, the largest annual addition.

The grid operator’s 10-year transmission plan that examines the construction of new transmission infrastructure over a shorter period recommends $2.9 billion in projects to advance the reliability and access to clean energy generation.