Vehicle-to-Grid is Not a Science Project

California added over 250,000 electric vehicles last year, reaching more than one million , according to the California Energy Commission. Current gasoline price spikes suggest that growth will accelerate EV purchases even more, but the increased electricity demand is expected to tax the power system, particularly if charging is not done at optimal times.

In response, California utilities are working on electric vehicle to home pilots that explore using the vehicles’ battery storage to power customers' homes during outages , as Current recently reported .

Pacific Gas & Electric and GM are working on a pilot over the next year at a utility facility and then at a customer’s home to test bidirectional chargers’ V2H capabilities. Concurrently, five PG&E-powered homes will test the potential of bidirectional charging with Ford’s F150 Lightning , the first light-duty truck in the market with that capability, PG&E Spokesperson Ari Vanrenen said. It will include management of the F-150 battery through Sunrun-provided home energy management systems , Ford Motor Company, Energy Services Business Lead, Ryan O’Gorman told Current .

But the big prize is expected to be vehicle to grid (V2G) technologies emerging to support California’s 2035 all zero-emission new vehicle sales goal and its grid reliability ambitions, transportation electrification sector representatives and analysts told Current .

People have been talking about V2G for 20 years, but implementation is only accelerating now, said Nuvve Vice President of Policy Jacqueline Piero. V2G is ahead of the PG&E pilots’ more narrowly focused vehicles to homes. That is because V2G interconnection rules are in place, safety standards are developed, and policies supporting compensation are coming soon, she added.

V2G “is not a science project anymore,” agreed Vehicle Grid Integration Council (VGIC) Senior Policy Director Edward Burgess. Many other major automakers besides Ford and GM, including VW, Lucid, and Hyundai, are working on the technology. California, New York , and Massachusetts are working on policy to support and compensate it, he added.

V2G

Bidirectional charging technologies that enable vehicle to home and V2G are the way of the future because of the “huge opportunity” for customers, utilities, electric systems, and automakers, PG&E’s Vanrenen said.

There is value for all customers when a bidirectional charger converts AC electricity stored in an EV battery and sends it to a building as backup power or to the power system to smooth demand peaks, a November 2021 Smart Electric Power Alliance report confirmed.

To scale V2G, "technical standards that govern the integration of V2G-enabled EVs” need to be incorporated into state interconnection rules, a January Interstate Renewable Energy Council report said. No single standard will cover all V2G interactions, but national standards by UL, IEEE, and others have established guidance for “safe and reliable” V2G performance, the report said.

A July 21, 2017, California Public Utilities Commission rulemaking on Distributed Energy Resources interconnection opened the door to V2G technology as a form of stationary storage, Nuvve’s Piero said. SB 676 passed in 2019 added momentum to V2G’s growth by ordering the commission to develop and implement “ vehicle-grid integration strategies ,” said VGIC’s Burgess. That was done in Decision D.20-12-029 , allowing companies like Nuvve, Fermata Energy , and dcbel to begin optimizing interactions of bidirectional chargers with utility systems.

The next major milestone for V2G came with a December 2021 commission rulemaking authorizing aggregated EVs for its Emergency Load Reduction Program (ELRP), Burgess said. It provides $2/kWh for EV aggregations that reduce load or deliver supply of 25 kW or more for 30 hours annually during system emergencies. This is California’s first regulatory commission approval of compensation for V2G, he said.

The ELRP “guarantees a revenue stream” to EV or charging system aggregators by requiring utilities to dispatch those resources as load reductions or generation, Burgess said. This summer and the next one, V2G could add “hundreds of MWs” of reliability during extreme weather events and significant compensation to EV owners, he added.

Standard two way charging in buses

Because of the V2G potential, bidirectional charging capability is becoming standard for electric bus manufacturers like Blue Bird , Lion Electric , and BYD , Burgess said.

Nuvve plans to be among the first to participate in the San Diego Gas & Electric summer 2022 ELRP program using aggregations of its 1.5 MW fleet of V2G-enabled Bluebird school buses, Piero added. For SDG&E-called events, Nuvve will manage its fleet to assure the 25-kW minimum is available throughout the event duration but also to assure the buses are ready for use when needed, she added

Just approved federal infrastructure bill funding will likely be the next “gamechanger” for transportation electrification and includes several V2G provisions, Piero said.

But V2G proponents hope the decisive step in California will come from proposed utility rates and pilots summarized in their September 2021 interim reports to the commission .

The first opportunity is expected from SDG&E’s V2G-Export Rate, which was submitted for commission approval in December 2021. It would compensate “energy exports to the grid from commercial EV charging stations and fleet vehicles” for “reliability during periods of peak demand,” according to the utility’s testimony .

SDG&E has also proposed an electric bus pilot to test “numerous V2G services,” including “facility peak shaving and potentially grid export, it reported to the commission . But that pilot awaits “completion of bidirectional software” and bus retrofits, spokesperson Krista Van Tassel told Current .

PG&E has completed some temporary V2G interconnection work and is developing “rates that encourage VGI,” it reported . A pilot with compensation for exported generation using wholesale market rules and prices “is currently pending approval.” Lessons learned are expected to point to potential next steps.

Southern California Edison pilot projects will explore integration of energy storage systems and microgrid control strategies with EV charging systems, it reported . It is also developing interconnection rule reforms, technical standards, customer education programs, and options for medium- and heavy-duty EVs.

Barriers

Too often, however, pilots and proposals like these do not overcome the barriers that prevent them from being implemented at scale, analysts have found .

Vehicle grid integration (VGI) is “a nascent market” and lack of research and data are “barriers” to implementation, PG&E’s September report said. Both historic data on customer behavior and access to emerging customer data are lacking, it added.

This common utility concern was echoed in the reports from SCE and SDG&E but is likely to be resolved by data from emerging pilots, proponents said. The bigger question is what utilities will do with the data and other pilot results when it is available, the proponents added. Pilots could be more effective if they include plans for moving them to scale deployments, according to analysts .

Concerns that V2G’s increased EV battery and electrical system use will compromise vehicle durability and vehicle warranties, impeding V2G progress is also not a “fundamental” barrier, VGIC’s Burgess said. The monetary and other values to drivers and to power system reliability for infrequent emergency events outweigh potential costs, he said.

A bigger barrier to long-term V2G growth is varying interconnection rules and processes in 50 states instead of national standards and best practices , Burgess, Ford’s O’Gorman, and GM’s Lienert agreed. Policy “can enable and accelerate V2G by simplifying interconnection and by unlocking market mechanisms for compensation,” Lienert said.

EVs should be compensated for their value to the power system, Piero agreed. A new regulatory approach could recognize V2G’s potential to support power system reliability and allow utilities to use price signals to call on EV value “when it is needed.”