Vehicle-grid integration (VGI) is the facilitation of flexible charging (and discharging) of an increasing number of EVs in a way that benefits rather than negatively impacts the transmission, generation, and distribution systems. VGI can provide benefits to EV owners, the broader EV ecosystem, and ratepayers. All CPUC transportation electrification programs and policies support VGI in some manner, as the CPUC aims to align EV charging with the needs of the electric system. The items below are some examples of our recent VGI work.   

Senate Bill (SB) 676 (Bradford, 2019)

In 2019, SB 676 (Bradford, 2019) created new requirements for all IOU TE programs to maximize achievable VGI benefits by 2030 and directed the CPUC to issue guidance on VGI strategies and metrics no later than December 31, 2020.

In August 2019, Energy Division staff launched a VGI Working Group with eighty-five participants, including CARB, the CAISO, CEC, IOUs, community choice aggregators (CCAs), EV manufacturers, battery manufacturers, charging network and energy service providers, advocacy and research groups, ratepayer advocates, and industry groups. This 2019 working group was preceded by one in 2017 that aimed to assess the need for adopting communication protocols.

A resulting report from the second working group, the June 30, 2020 VGI Working Group Report, provided 90 policy recommendations in response to the question: what policies need to be changed or adopted to allow additional VGI use cases to be deployed in the future. The CPUC issued a supplemental VGI Staff Paper to stakeholders in August 2020, requesting additional feedback.

In December 2020, the CPUC issued a Decision regarding VGI implementation strategies and quantifiable metrics that meet the criteria of SB 676—Decision (d.) 20-12-029. The Decision establishes a foundation for efforts to maximize VGI and requires the use of certain VGI strategies in other transportation electrification programs.

VGI Pilots

The CPUC has also overseen several electric IOU pilots to explore VGI applications, including demand response pilots using EVs to shift or curtail load, pilots to explore managed charging, and pilots that have examined use cases and technological feasibility of vehicle-to-grid (V2G).

Within the December 2020 SB 676 decision, the CPUC authorized the IOUs to spend up to $35 million on pilots to overcome barriers to VGI that are technically feasible, but not yet commercially available. SCE and PG&E have each submitted VGI pilot proposals pursuant to this decision, and PG&E’s approved pilots began pre-enrollment in November 2022

Technology and Standards

The CPUC works with our sister agencies to further technology and standards related to electric vehicle supply equipment (EVSE). In particular, the CPUC has been working with the CEC to require communications standards between the EVSE and the network—OCPP—and the EVSE and the EV—ISO 15118. SDG&E’s Power Your Drive Extension program was the first of the CPUC’s to require both of these standards, while resolution E-5175 concerning SCE’s Charge Ready 2 adopted a phased approach to requiring ISO 15118. These efforts are closely aligned with those of the CEC, which in November 2021 issued a proposal to phase in a requirement for ISO 15118—the ISO 15118 Charger Communications and Interoperability Proposal.

In August 2022, the CPUC adopted EVSE communication protocols via D.22-08-024 as minimum qualification requirements for all EVSE installed via ratepayer funding or through an IOU administered program. Per this decision, all EVSE deployed by July 1, 2023, must be capable of the following:

  • All AC-conductive EVSE for light-duty uses cases must be equipped with an SAE J1772 connector; 
  • All DC-conductive EVSE deployed for light-duty use cases must be equipped with a CCS connector;
  • For all EVSE, communications and controls between a network service provider and the EVSE shall be capable of operating on OCA OCPP 1.6 or later; 
  • All EVSE must be ISO 15118 ready, and be equipped with onboard hardware that enable high-level communications with the vehicle using ISO 15118. An ISO 15118-ready charger is capable of, at minimum: a) a powerline carrier based high-level communications as specified in ISO 15118-3; b) secure management and storage of keys and certificates; c) Transport Layer Security (TLS) version 1.2, with additional support for TLS 1.3 or subsequent versions recommended to prepare for future updates to the ISO 15118 standards; d) ability to receive remote updates to activate or enable ISO 15118 use cases; e) connection to a backend network; and f) capability of selecting the appropriate communication protocol used by the vehicle.

The process to adopt these communication protocols involved many years of stakeholder input and interagency collaboration. Notably, the 2017 VGI Communications Protocol Working Group assessed how and whether the adoption of a communication protocol is necessary to enable VGI resources to more economically participate in electricity markets. The working group allowed participants to review and discuss the technical details of existing protocols, and resulted in a report linked below.

VGI Strategy in the Transportation Electrification Strategy and Investment Decision

The CPUC’s recently adopted Transportation Electrification Strategy and Investment decision (D.22-11-040), also known as the Transportation Electrification Framework decision, laid the foundation for the next phase of VGI strategy and execution. To better focus stakeholder attention on the core IOU VGI activities, the decision established three strategic focus areas for VGI: (1) rates and demand flexibility programs; (2) technology enablement; and (3) planning. These areas will be explored in-depth at an annual VGI Forum, where the CPUC, IOUs, and other stakeholders will discuss advances in VGI and how best to accelerate adoption of the most promising VGI strategies. The forum will be divided into topic areas:

  1. Rates and Planning: This topic area of the forum focuses on the linkages among planning, rates, and demand flexibility programs and proceedings. This will be held as a part of the CPUC’s Annual Rate Forum and include presentations on progress, gap assessments, and the need for EV-specific rates.
  2. Technology Enablement: This topic area of the forum focuses on technology enablement, VGI technology in existing IOU programs and pilots, and the incorporation of new technology developments into future IOU transportation electrification investments. This forum will coordinate with the CEC’s VGI staff to showcase recent developments (e.g., emerging technology, coordination on VGI equipment certification, etc.).

Through these forums, the IOUs will file workshop reports and may propose modifications to TE programs based on the discussions at the forum via advice letter.


Vehicle-Grid Integration Activities