Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Home Joint Office of Energy and Transportation

Electric Vehicle Charging Data and Communications Protocol Interoperability

Building a connected and secure electric vehicle (EV) charging ecosystem requires digital infrastructure that works together. The Joint Office convenes and guides both open-source and common framework approaches for solutions that will improve how drivers plan, charge, and use energy.

Creating Consistency in EV Charging Communications Protocols and Data Sharing To Better Connect the Ecosystem and Share Data With Consumers

From charging stations and vehicles to utility systems and back-end payment systems, there are many different pieces of the charging experience that need to communicate effectively for successful charge. The Joint Office aims to simplify these connections in part through open-source tools that reduce opportunities for incompatibilities due to proprietary systems and maximize the benefit of EVs to the grid.

The Joint Office has a partnership with Linux Foundation Energy to build independent, open-source software tools aligned with this goal. Called EVerest, this open-source software project develops and maintains a software stack for EV charging stations with libraries for the communication protocols used to communicate with EVs, to other chargers and to the back-end IT infrastructure.

Read more about EVerest and how to participate.

Additionally, securely sharing data within the EV charging ecosystem can help users to more easily find and access accurate information about charging stations and help system operators identify problems quickly. Having a standardized protocol for real-time APIs can facilitate that, allowing third-party software developers to aggregate charging station data and provide mapping services and other useful apps to drivers.

The Joint Office developed a recommendation to create this standardized protocol, including how to structure data, when to update data, and best practices for how to make API data usable for improving the customer experience.

Read Standardized Protocol for Real-Time APIs as Required by Title 23 CFR 680.116(c).

Improving the Charging Experience With Common Security Frameworks

Because the charging experience is different depending on what vehicle you have and the charging station used, different apps and payment methods are currently part of the process, introducing the potential for compatibility issues and errors. This also creates an inconsistent user experience.

The Joint Office has provided its expertise and research-backed approaches to an authentication solution for EV charging that will enable universal Plug & Charge: the ability to plug in a car to a charger and automatically begin the charging transaction—no extra payment step or authorization required. The solution is called Electric Vehicle Public Key Infrastructure (EVPKI) and is set to begin rolling out in 2025.

The EVPKI approach to creating universal Plug & Charge also enables the architecture necessary for bidirectional charging. This opens future innovation in areas like vehicle-to-grid integration and vehicle-to-everything communications.

Read more about the EVPKI framework and universal Plug & Charge.

Facilitating Vehicle, Charger, and Grid Communication With Open Standards

In addition to reducing opportunities for interoperability issues, common frameworks and open-source tools are also unlocking new innovations in the charging experience. For example, ISO 15118 and Open Charge Point Protocol enable managed charging and related features, like departure time. By using shared information models of grid constraints and incentives and preferences of individual drivers, drivers can plug in and set a time by which they would like to get a full charge, with the EV managing the rate of charging to lower costs, manage the load on the grid, and ensure the driver can leave on time, fully charged.

Open-source tools can be used to make these kinds of features easier to implement. For example, the case where an EV optimizes charge rate to meet grid constraints while still reaching a designated state of charge by a specified departure time was demonstrated within the EVerest open-source software tools to illustrate how various standards and protocols can be paired to enable features. The code base for this feature is free and openly available to run on any laptop with a single line command through EVerest. This illustrative use case of managed charging was demonstrated to the EV charging industry at the CharIN Testival North America 2024.

You Might Also Like

Return to top