E3 has provided comprehensive technical and advisory support to the Energy Division of the California Public Utilities Commission (CPUC) in its administration of the state’s IRP program, mandated by the passage of SB 350 in 2016.  E3 worked with CPUC staff to develop the structure of the IRP program including a three-year modeling cycle in which Staff prepares a system-wide plan that informs the California Independent System Operator (CAISO)’s annual Transmission Planning Process (TPP) and informs Load-Serving Entities integrated resource plans in alternate years.

E3 has helped the CPUC design an optimal “Preferred System Plan” for the combined utilities that incorporates the resource procurement plans of the LSEs and complies with the state’s clean energy policy requirements. In the 2022-2023 cycle, the policy requirements considered include a 60% RPS by 2030 and SB 100 by 2045, and a statewide greenhouse gas emissions target of 25 million metric tons (MMT) by 2035, while capturing the operational and reliability challenges encountered at high penetrations of variable renewable generation. As part of this process, E3 evaluated dozens of scenarios reflecting alternative assumptions about load forecasts and electrification, resource costs, the availability of offshore wind and out-of-state wind, the ability of end-use loads to operate flexibly, and a variety of other input parameters.