It’s a pretty good bet that most of us haven’t thought much about vehicle-to-grid technology (V2G). It’s one of those techs that’s evolving and starting to attract an audience. It has numerous advantages, but also many challenges. What is V2G tech? It’s a bidirectional charging technology that can either charge the parked electric vehicle’s (EVs) battery or send its power back into the grid, but implementation is complicated. Interestingly, V2G is about to reach the point where there are sufficient numbers of EVs available to play a significant role in improving the flexibility of the power grid.
Several current news releases reported on the upward trend being experienced in EVs sales in recent years. Worldwide, about 14 million EVs were sold in 2023. The EV industry was excited by that quantity bringing the total number of EVs on the road to about 40 million. The projections indicate this trend will continue growing. With those increasing numbers of EVs, there’s excitement for both the EV manufacturers and the grid operators because of the possibilities for that V2G tech represents.
Batteries on Wheels
One EV with the ability to supply power to its home is important to that homeowner, but it hasn’t generated much interest from electricity providers. However, if several hundred or thousands of EVs were aggregated together that’s electrifying. These combined EVs make it a totally different ballgame. Imagine, suddenly V2G tech is capable of being scaled to megawatt-hours of energy storage. That gets everyone’s attention, from EV fleet operators, third party aggregators, grid operators, etc.
It’s similar to having mobile microgrids available throughout the network, since the EVs move between different charging points during a typical day. They can be utilized wherever V2G-equipped public parking points are located. These mobile batteries can have a stabilizing effect on the power grid. This is especially important as the power grid shifts toward more wind and solar renewable energy. V2G tech can diminish grid challenges rather than exacerbating them.
It's important to remember that V2G tech not only offers stored energy, but it can provide ancillary grid-services. As more of these renewable energy sources come online, the need for ancillary grid-services increases. They address local grid challenges like frequency support, voltage support, congestion management and power flow support to name a few. There are, however, some infrastructure issues that still need to be addressed.
Hardware Hodgepodge
The EV infrastructure is beset by proprietary technologies. In short the EV industry has not addressed interoperability. An example can be seen in the public EV charging process. A driver of an EV from automaker A can only use a compatible non-standard public charger. The same holds true for EVs from automaker B and so on. There is no universal charger that accepts any EV driven to it. For that matter, there’s no standard charger plug-in/port hardware.
While we’re on the subject, very few of today’s public charging hardware is capable of bidirectional charging, which is critical for V2G tech. That’s not to say the technology doesn’t exist. It does, but its limited and standards are in development. Also, there are only a few EVs that come equipped with their own bidirectional charging features such as the Ford F-150 Lightning or the Nissan Leaf. Interestingly, Tesla has included this feature in their Cybertrucks. It’s been speculated that more of its future models will incorporate this feature.
Speaking of Tesla, they made V2G interoperability news with a series of announcements last year. Their first announcement revealed they were making the design and specifications for their network’s charging plug-in/port hardware available to the EV industry. Next they renamed that hardware the North American Charging Standard (NACS) connector. Then another statement said seven automakers had adopted the NACS standard. That group has expanded and now it’s easier to list who is not in it than who is!
This was followed by SAE International’s publication “J3400 Technical Information Report.” It recognized the NACS connector as the standard connector for EVs and renamed it the J3400 connector. SAE’s report said that now any North American manufacturer can use the J3400 connector on their EVs and charging stations. This too has been met with widespread industry acceptance. Automakers have begun supplying adapters for current EV models and said they will be using the J3400 hardware on their 2025 EVs.
Tricky Situation
Standards wise we have to ask how is V2G tech controlled gridwise? How is permission given for vehicles to charge/discharge at various times? How will aggregated EV batteries operate as a single power source? What about communication protocols? Those are only a few of the basic questions posed by grid operators and third party developers. It shows how badly we need these standards and protocols, and the standards organizations are working to address these and other issues.
With that in minded, it’s time to talk with the experts. “Charging Ahead” contacted Mark Siira, the chairperson of IEEE’s Standards Coordinating Committee 21 to get his views on this complex subject. Mr. Siira and Committee 21 have been working on the standardization/interoperability standards that are necessary for making the EV infrastructure more efficient and user-friendly.
Mr. Siira began the discussion saying, “As we look at the issues facing the EV infrastructure it’s evident that interoperability and standards are becoming increasingly important for enabling the EV industry and the power grid to work together. Standards establish common terminology and the framework needed to ensure safety and guarantee reliability of the product. They also give clarity to specifications and requirements. Standards improve the overall quality of the installations that the industry relies upon. This is especially important when we consider how the demand for EVs has skyrocketed in the past five years and where it’s going in the next decade.”
Siira continued, “As standards are developed, the ability for EV manufacturers to work together increases. This is important for overcoming proprietary technologies used by many in the EV industry. Developing standardization ensures that all future EV systems are mutually compatible and interoperable by design. These interconnection standards are needed for the automotive and power grid to work together. IEEE SA is working on several elements that have been recognized as needing smoother interface points. One of the most successful standardization projects has been the J3400 connector, but that’s only the beginning. Another area attracting attention of the standards community is EV charging plazas.”
Mr. Siira explained, “ Proprietary technologies slow progress toward fast charging plazas as a user-friendly facility. Initially, suppliers developed proprietary technologies for charging their EVs. It wasn’t an issue when the EV charger was in the owner’s garage, but it became an issue away from home. Consumers want reliable fast-charging stations wherever they travel like gas stations for internal combustion engine vehicles. Doing that requires an EV technology that works across the EV infrastructure. On the surface an EV charging plaza may not seem that complicated, but that’s not the case. Large charging plazas integrate a wide variety of digital technologies, which interface with each other throughout the plaza and with the power grid on the other side of the meter, which requires a great deal of operational coordination.”
Siira concluded, “User-friendly charging plazas need sophisticated energy management systems to make it happen. It starts with the monitoring and control of EV charging profiles where projecting charging station energy needs will be critical. Many of these charging plazas will have supplemental power sources such as a BESS (battery energy storage systems) or other DERS (distribution energy resource systems). They have to function together perfectly, which aids in the collaboration between the plaza and the power grid. All this and more is why standards are important as EV deployment grows.”
Contributing to Grid Stability
It goes without question, proprietary technologies are needed for innovation and offer stability for product development, but with many technologies there’s a point where moving to interoperability is necessary for both the developer and the customer. It happened with many other technologies and it’s happening with EV tech. We saw what is happening with the interface between the EV and the power supply.
Consumers have been struggling with the non-standard chargers and their hardware. It’s resulted in potential EV buyers sitting on the sidelines waiting to see what falls out. Another issue is the charger itself. Most (i.e., Level 1 and 2) are unidirectional and only compatible with specific EVs. Everybody needs to be on the same page with the compatible hardware. That requires interoperable and standardization for the EV infrastructure.
Standards organizations like IEEE SA, SAE International, ANSI, IEC to name a few are working on these and other EV tech issues. V2G technologies are available and have the potential to make a sizable difference for owners with a revenue stream and improved grid stability via grid-support services, but interoperability is critical. V2G will bring much needed flexibility and resilience to the grid!
