Technical resource
Smart Charging and V2X Fact Sheet
As electric vehicle sales keep growing, their interactions with the electric grid matter more. Vehicle-grid integration and bidirectional charging are real opportunities to reduce cost of ownership and improve grid resiliency.
Summary
Non-commercial EV owners
Managed charging is usually the most feasible option: lower energy costs, plus participation in utility demand-response programs where they exist.
Larger fleets
Vehicle-to-Grid (V2G) can generate revenue to offset ownership costs, especially where vehicles have well-defined routes and dwell times. It also carries substantial up-front expense and effort, including utility coordination and added technology requirements.
Facilities with resiliency demands
Vehicle-to-Building systems can power critical loads through grid outages and help optimize on-site generation and consumption — with the same high interconnection cost and effort as V2G.
EV trends
- The global market passed 20 million EV sales in 2025.
- EV sales share in the U.S. is currently 10%, lagging well behind China, Europe, and the global average.
- The number of EVs capable of bidirectional charging continues to grow, but only represented about 5% of EV models in production last year.
Bidirectional charging
EV and charging systems that can both charge and discharge energy from vehicle batteries are bidirectionally capable.
- V2X means “vehicle-to-everything” — a catch-all for the applications of bidirectional charging, including Vehicle-to-Grid (V2G), Vehicle-to-Building (V2B), Vehicle-to-Home (V2H), and Vehicle-to-Load (V2L).
- For available incentives, check your local electric utility, the Department of Energy's Alternative Fuels Data Center, and the Database of State Incentives for Renewables & Efficiency.
- Description, benefits, challenges, and use cases for each application follow below.
Managed charging (V1G)
One-way EV charging managed by software that varies session times and power levels against a pre-determined schedule or grid signals. Also known as smart charging.
Example use cases
- An EV owner scheduling charging for the lowest electricity rates
- An EV fleet aligning charging sessions with the lowest-emission grid periods
Benefits
- Reduced energy costs through time-of-use rates
- Ability to optimize 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
Vehicle-to-Grid (V2G)
A bidirectional system in which EVs export energy directly to the grid, serving as a dispatchable energy resource for the utility and a grid-connected storage asset for the EV owner.
Example use cases
- An electric school bus fleet charging overnight and discharging during summer load spikes
- A rental car fleet providing ancillary services such as frequency regulation or voltage support to the 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
Vehicle-to-Home (V2H) & Vehicle-to-Building (V2B)
Bidirectional systems that let EVs serve as a power source for facilities, in commercial (V2B) or residential (V2H) settings. One EV can cover the average household's energy needs for up to three days.
Example use cases
- An emergency services facility powering critical infrastructure through a grid outage
- A home with solar generation optimizing EV charge and discharge cycles to cut grid 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
Vehicle-to-Load (V2L)
The ability for EVs to power plug loads directly from the vehicle, typically through onboard outlets or a charge port adapter.
Example use cases
- Remote power for an off-grid construction site
- Emergency power to refrigerate 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 — plug loads only
- No external financial incentives
V2X technology considerations
Every one of these has to line up before a bidirectional project is feasible.
Electric vehicles
- Must be capable of bidirectional charging flows
- Interoperable with the EVSE
- Able to send and receive communications for charge and discharge cycles
Electric vehicle batteries
- Battery management system to hold an optimal temperature range and charge/discharge rates for battery health
- Potential battery degradation from the additional kWh of throughput in V2X applications
- Warranty implications: some OEMs set explicit limits against V2X deployments, including maximum kWh of throughput or specifically approved EVSE makes and models
Electric vehicle supply equipment
- Must be capable of bidirectional charging flows
- Interoperable with the EV
- Able to convert DC electricity from EV batteries to AC for the local grid or facility, unless the EV carries an inverter
- Able to send and receive communications for charge and discharge cycles
- Additional infrastructure for load aggregation across multiple EVs
Interconnection with the 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
Facility
- System controller connecting the bidirectional charging system to the main electrical panel, or to an auxiliary panel for critical loads
- Communication protocols so the system can detect grid outages and disconnect the facility from the local distribution grid
Software
- Interoperable with EV, EVSE, and grid or facility communications protocols
- Able to automate charging sessions against a goal: utility signals, time-of-use rates, emissions, and so on
See the vehicle-grid integration standards below for the relevant standards, certifications, and communications protocols.
Vehicle-grid integration standards
| Standard | Description |
|---|---|
| IEC 63110-1 | Protocol for management of electric vehicle charging and discharging infrastructures — Part 1: basic definitions, use cases and architectures |
| IEEE 1547-2018 | Interconnection and interoperability of distributed energy resources with associated electric power systems interfaces |
| IEEE P2030.5 | Smart Energy Profile application protocol |
| ISO 15118-20 | Road vehicles — vehicle-to-grid communication interface, part 20: 2nd generation network and application layer requirements |
| NEMA EVSE 40011 | EVSE power export standard |
| OCPP 2.0.1 | Open Charge Point Protocol 2.0.1 |
| OCPP 2.1 | Open Charge Point Protocol 2.1 |
| SAE J2847/1 | Communication for smart charging of plug-in electric vehicles using Smart Energy Profile 2.0 |
| SAE J2847/2 | Communication between plug-in vehicles and off-board DC chargers |
| SAE J2847/3 | Communication for plug-in vehicles as a distributed energy source |
| SAE J2847/5 | Communication between plug-in vehicles and customers |
| SAE J3068/2 | Control of bidirectional power for AC conductive charging |
| SAE J3072 | Interconnection requirements for onboard, grid support inverter systems |
| UL 1741 | Inverters, converters, controllers and interconnection system equipment for use with distributed energy resources |
| UL 9741 | Electric vehicle power export equipment (EVPE) |
| OpenADR 2.0, 3.0 | Communications between electricity providers and DERs, operators, aggregators, and customers |
Vehicle-grid integration advocacy groups
| Group | Description |
|---|---|
| Vehicle-Grid Integration Council (VGIC) | Advocacy group for advancing smart EV charging, including vehicle OEMs, EVSE and software providers, and utilities. |
| Task 53 | An EV Technology Collaboration Programme from the International Energy Agency, working to ensure interoperability between bidirectional charging stations, vehicles, and distribution grids. |
| CharIN | Global association with over 300 members dedicated to promoting EV charging standards. |
| OpenADR Alliance | Global alliance created to standardize, automate, and simplify demand response and distributed energy resources. |
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