By Rachel Rockwell
At its February 11, 2021 voting meeting, the California Public Utilities Commission (CPUC) adopted D.21-02-008 to transfer electric resource portfolios to the California Independent System Operator (CAISO) as part of its ongoing rulemaking proceeding, R.20-05-003. The decision recommends electricity resource portfolios for the CAISO to study in its 2021–2022 Transmission Planning Process (TPP). Every year the CPUC recommends to the CAISO electricity resource portfolios, including one reliability and one policy-driven base case, and two sensitivity cases.
On October 20, 2020, an Administrative Law Judge (ALJ) issued a ruling seeking party comments on the CPUC staff recommendations for portfolios to be used in the 2021–2022 TPP. The ruling included a recommended framework for TPP portfolio selection, descriptions of the proposed portfolios, and a methodology for resource-to-busbar mapping and assumptions. The recommended reliability and policy-driven base cases were identical, with a recommendation for the portfolio that meets the 2030 greenhouse gas (GHG) target of 46 million metric tons (MMT), adopted in D.20-03-028. The first recommended policy-driven sensitivity portfolio meets the 2030 GHG target of 38 MMT. The CPUC designed the second policy-driven sensitivity portfolio to obtain improved transmission capability and upgrade cost estimates for certain areas on the CAISO system to aid in modeling offshore wind as a future candidate resource. The ALJ ruling also contained updates in mapping for battery storage, non-battery resources, and thermal generation retirement assumptions. This proposed base case portfolio includes the largest amount of battery storage ever examined by the CPUC.
In D.21-02-008, the CPUC did not formally adopt the framework created by Commission staff for evaluating TPP portfolios but will use the framework and party comments to inform future rounds of evaluation of TPP portfolios. The decision continues to recommend the 46 MMT GHG emissions target portfolio with updates from the California Energy Commission’s 2019 Integrated Energy Policy Report. This portfolio identifies over 9 GW of new battery storage, over 16 GW of new in-state renewables, and over 1 GW of out-of-state renewables on new transmission. The 38 MMT portfolio is currently being analyzed as a potential preferred system portfolio for the 2022-2023 TPP cycle.
The decision became effective on February 11, 2021.