Published on May 9th, 2023, this study, commissioned by the CPUC, aims to determine the electric grid requirements at the distribution circuit level, assuming the state achieves its transportation electrification goals by 2035. The study covers the Pacific Gas and Electric (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E) service territories.

Cover Sheet

California has some of the most progressive environmental policies and greenhouse gas reduction goals in the world. Senate Bill (SB) 100 established a landmark policy requiring renewable energy and zero-carbon resources supply 100 percent of electric retail sales to end-use customers by 2045.

The California Public Utilities Commission initiated the High Distributed Energy Resources Grid Planning Rulemaking in July 2021 to prepare the electric grid for anticipated high adoptions of Distributed Energy Resources (DERs), including those associated with transportation and building electrification.

The Electrification Impacts Study Part 1 (Part 1 Study) was prepared for review within the High DER Proceeding as a first step towards examining the potential impacts of high adoptions of DERs on the distribution grid, identifying where and when enhancements and investments could be needed, and estimating the potential costs of meeting these needs.

The Part 1 Study presents a granular bottom-up load forecasting methodology that provides locational and temporal information on where and when distribution grid enhancements may be needed. Part 1 study also estimates potential system level costs under an unmitigated scenario.

The preliminary results from the Part 1 Study estimate approximately $50 billion for distribution grid investments by 2035 to accommodate a High DER grid future if measures are not taken to reduce costs and manage load. It is important to consider the system-level cost and load estimates presented in the Part 1 Study to be preliminary.

It should be noted that the Part 1 Study estimates the potential costs of meeting infrastructure needs being exclusively met with distribution assets without considering new real-time dynamic rates and flexible load management strategies. California’s aging grid will also require upgrades in certain areas to ensure continuity of service to support current DERs and load, even in the absence of additional DERs.

This study is a learning experience and a starting point to open the discussion on how to reimagine distribution grid planning for the twenty first century and consider the design and implementation of the distribution system needed to accommodate a High DER grid future.

To meet this challenge, it is critical that we receive stakeholder participation in reviewing this study. The Energy Division staff underscore that this is a beginning point in the discussion, and welcome feedback and comments on the Part 1Study and the proposals for future iterations.