V2G technology is a significant development in the energy sector. It enables energy to be pushed back to the grid from the battery of an electric vehicle. Smart charging V2G technology allows batteries to be charged and discharged based on different signals. This technology can be used to balance variations in energy production and consumption, as well as to mitigate climate change by maximizing the use of renewable energy resources, which cannot be easily stored as fossil fuels.
While smart charging benefits to balance the grid and mitigate climate change ends once the EV's battery is fully charged, V2G technology goes further by optimizing the power systems for as long as the car is plugged into the grid.
According to Statista, by 2030, Europe is estimated to have 40 million EVs, this represents an impressive storage capacity of 2400GWh. This potential can revolutionize the energy sector, offering an efficient way to manage energy and contribute to a more sustainable future for all.
In April, Jedlix spoke at the Vehicle 2 Grid conference in Aachen, where industry leaders discussed V2G and its future. Below, you find the main takeaways from this conference:
Battery degradation: when an EV’s battery is used for V2G, it is charged and discharged more often than in normal use, reducing the battery's capacity and overall lifespan. However, smart charging technology embedded into V2G systems can monitor the battery's state of health and control the charging and discharging cycles to minimize degradation, as demonstrated by numerous projects (example). Therefore, this seems to be no longer a significant issue. Yet, this impact will be further reduced as larger batteries emerge.
ISO15118-20: This is the communication protocol standard that defines the interface between EVs and charging stations. Although the implementation of this standard should vary, industry experts believe that the Dynamic Mode feature should be adopted as it enables real-time communication between the EV and the charging station during charging and discharging. That allows the EV to respond dynamically to changing grid conditions and therefore, adjust its charging or discharging rate accordingly. For instance, if the grid frequency drops, the EV can reduce its charging rate to help stabilize the grid.
Double taxation and grid tariff structures: These remain a significant issue in several regions, which hampers the business cases and usability of bi-directional smart charging. If these issues cannot be easily resolved due to the complexity of changing systems, it may be necessary to provide targeted grants and incentives for bidirectional charging to encourage its adoption.
AC/DC: There is still a (religious) debate between AC vs DC for bi-directional charging, and both technologies are progressing steadily. It is safe to assume that both technologies will coexist and therefore, incentives and policies should take this into account.
Currently, AC systems are more compatible with bidirectional power flow, have less expensive infrastructure when compared to DC and are more flexible. On the other hand, DC charging is faster, more efficient and eliminates the need for an onboard charger.
Automotive OEMs are taking the initiative on AC V2G while DC bi-directional chargers are getting cheaper and more ‘market ready’.
(Dis)charging efficiencies: Charging and discharging efficiencies are important considerations for V2G systems. They impact the overall energy efficiency and economic viability of the structure. In V2G systems, charging and discharging efficiencies can be impacted by several factors such as the charging load, the EV's onboard charger, and the power electronics used in the V2G system.
When these systems are designed for home/solar use cases (V2H), charging and discharging efficiency can remain challenging. EVs lose a substantial amount of energy when operating at low charging speeds, which can go up to 25-40% when operating below 2 kW. This can impact the overall efficiency and economic viability of the V2H system.
Furthermore, the impact of V2G on a street/neighbourhood level is significant. As more EVs are added to the grid, the impact of their charging and discharging activities can have a significant effect on the local energy grid. Therefore, it is important to design V2G systems with appropriate rules and incentives to encourage users to consider the broader impact of their actions on the local energy grid and their communities. This could include incentives such as pricing structures that encourage users to charge during off-peak hours, or regulations that require EV owners to participate in V2G programs in exchange for certain benefits or privileges.
When it comes to timing and large-scale deployment of V2G systems, there have been several promises on timelines that have not been achieved so far. However, the tipping point for V2G deployment is not far away. As more and more stakeholders become aware of the benefits of V2G systems, we are likely to see an increasing push towards large-scale deployment.
Many initiatives, including those at Jedlix, are actively working towards implementing V2G systems on a larger scale and it is only a matter of time before V2G systems become a reality for communities around the world.