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Smart Charging and V2X Fact Sheet

Summary:

As electric vehicle sales continue to grow, their interactions with the electric grid become more impactful. Vehicle-Grid Integration and bidirectional charging represent substantial opportunities for reducing vehicle cost-of-ownership and improving grid resiliency.

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  • Non-commercial EV owners: The most logistically feasible option will typically be managed charging to reduce energy costs and participation in utility demand-response programs, if available.

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  • Larger fleets: Vehicle-to-Grid represents a potential revenue generation pathway to offset vehicle ownership costs, especially when vehicles have well-defined routes and dwell times. However, there are substantial up-front expenses and effort required to implement these systems, including utility coordination and additional technology requirements.

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  • Facilities with resiliency demands: Vehicle-to-Building systems can power critical loads during grid outages and help facilities optimize on-site generation and consumption, though like Vehicle-to-Grid, these systems have high costs and effort for interconnection.

Graph of sales share of EVs by country in 2024. From left to right: World 20%, China 48%, UK 28%, Germany 18%, US 10%.

EV Sales Share (%)

Electric Car Sales Share (2024)

EV Trends:

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Bidirectional Charging:​

EV and charging systems that can both charge and discharge energy from vehicle batteries are bidirectionally capable.

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  • V2X refers to “vehicle-to-everything” and is a catch-all term for the many applications of bidirectional charging, including Vehicle-to-Grid (V2G), Vehicle-to-Building (V2B), Vehicle-to-Home (V2H), and Vehicle-to-Load (V2L).

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  • See below for description, benefits, challenges, and use-case examples for each of these applications.

Graphic that shows energy transfers in V2X system between electric grid, house, EV charger, and EV.
Graph of unmanaged and managed EV charging power levels and times compared against electricity costs.
Managed Charging (V1G)

One-way EV charging managed by software systems that vary charging session times and power-levels based on pre-determined schedule and/or grid signals—also known as Smart Charging.

 

Example Use-Cases:

  • EV owner scheduling charging times with lowest electric rates

  • EV fleet aligning charging sessions with lowest emission grid periods

Benefits:

  • Reduced energy costs through time-of-use rates

  • Ability to optimize charging sessions to reduce environmental impact

  • Potential utility incentives for demand-response programs

Challenges:

  • Technology costs for interoperable vehicle, charger, and software systems

  • More limited revenue and incentive potential than V2G applications

EV Charging Power Level (kW)

Electricity Cost ($/kWh)

3 PM     6 PM     9 PM     12 AM     3 AM

Unmanaged Charging

Managed Charging

(40% Cost Reduction)

Vehicle-to-Grid (V2G)

Bidirectional charging system in which EVs can export energy directly to the grid, serving as a dispatchable energy resource for the utility and a grid-connected energy storage asset for the EV owner.

 

Example Use-Cases:

  • Electric school bus fleet charging buses overnight and discharging electricity during load spikes in summer

  • Rental car fleet providing ancillary services like frequency regulation or voltage support to local distribution grid

Benefits:

  • Payments to EV owners for energy services

  • Grid resiliency through load balancing, energy exports, and ancillary services

  • Supports grid deployment of intermittent renewable generation

Challenges:

  • Technology costs for vehicle, charger, infrastructure, and software systems

  • Detailed planning requirements

  • Interconnection process

  • Inconsistent incentive market

Graphic of V2G system that shows ability of EV to export energy back to the electric grid.
Graphic of V2H system that shows a house islanded from the grid, with an EV and solar panel providing energy to the house.
Vehicle-to-Home (V2H) & Vehicle-to-Building (V2B)​

Bidirectional charging systems that allow EVs to serve as a power source for facilities in commercial (V2B) or residential (V2H) settings.

 

Example Use-Cases:

  • Emergency services facility powering critical infrastructure during grid outage

  • Home with solar panel generation optimizing EV charging and discharging cycles to reduce grid energy consumption

Benefits:

  • Resiliency during grid outages

  • Facility energy optimization

  • Supports deployment of on-site energy generation

Challenges:

  • Technology costs for vehicle, charger, infrastructure, and software systems

  • Detailed planning requirements

  • Interconnection process

  • Fewer financial incentives

One EV can power the average household's energy needs for up to 3 days. 

​Vehicle-to-Load (V2L)

​The ability for EVs to provide electric power to serve plug loads directly from the vehicle, typically through onboard outlets or charge port adapters.

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Example Use-Cases:

  • Remote power for an off-grid construction site

  • Emergency power for refrigerating medicine during a grid outage

Benefits:

  • No complicated technology or planning requirements

  • Off-grid power availability

  • Emergency power for critical plug loads

Challenges:

  • Limited applications, only plug loads

  • No external financial incentives

Graphic of V2L system that shows a pickup truck powering an air compressor on a construction site.

V2X Technology Considerations

Electric Vehicle
Batteries

  • Battery management system to maintain optimal temperature range and charge and discharge rates for battery health

  • Potential battery degradation from additional kWh of throughput in V2X applications

  • Warranty implications should be considered, as some OEMs have explicit limitations against V2X deployments—including maximum kWh of throughput in warranty terms or specifically approved EVSE makes/models

Electric Vehicle
Supply Equipment

  • Must be capable of bidirectional charging flows

  • Interoperable with EV

  • Able to pass DC electricity from EV batteries to AC for local grid or facility (unless EV is equipped with inverter)

  • Able to send & receive communications for charge/discharge cycles

  • Additional infrastructure requirements for load aggregation from multiple EVs

  • See Vehicle-Grid Integration table for relevant standards, certifications, and communications protocols

Interconnection with Distribution Grid

  • Sufficient power capacity for energy consumption and V2X energy exports

  • Utility interconnection approval and permitting

  • Grid-tie inverter and load aggregation systems

  • Automatic grid disconnect system for outages

  • Able to send & receive communications for charge/discharge cycles

  • See Vehicle-Grid Integration table for relevant standards, certifications, and communications protocols

Electric Vehicles

  • Must be capable of bidirectional charging flows

  • Interoperable with EVSE

  • Able to send & receive communications for charge/discharge cycles

  • See Vehicle-Grid Integration table for relevant standards, certifications, and communications protocols

Facility

  • System controller connecting bidirectional charging system to main electrical panel or auxiliary panel for critical loads

  • Communication protocols for system to detect grid outages and disconnect facility from local distribution grid

  • See Vehicle-Grid Integration table for relevant standards, certifications, and communications protocols

Software

  • Interoperable with EV, EVSE, and grid/facility communications protocol systems

  • System capabilities for automating charging sessions based on goals (utility signals, time-of-use rates, emissions, etc.)

  • See Vehicle-Grid Integration table for relevant standards, certifications, and communications protocols

Vehicle Grid Integration Standards

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