Bidirectional EVs Will Become Grid Assets

Author:
Shazan Siddiqi, Senior Technology Analyst and Technical Sales at IDTechEx

Date
11/12/2024

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Exploring the potential of vehicle-to-grid (V2G) charging

SWOT analysis of AC vs DC V2G systems. Source: IDTechEx - "Charging Infrastructure for Electric Vehicles and Fleets 2025-2035: Markets, Technologies, and Forecasts”

­As electric vehicles (EVs) continue to reshape the automotive landscape, the integration of Vehicle-to-Grid (V2G) technology offers transformative potential for both the energy grid and vehicle owners. V2G enables bi-directional energy transfer, allowing EVs to not only draw power from the grid but also return energy to it, effectively making EVs mobile batteries. This concept aligns with the broader trend of Vehicle-to-Everything (V2X) technology, which encompasses various forms of bi-directional energy exchange.

The rise of bi-directional EVs: V2X capable BEVs

A growing number of battery electric vehicles (BEVs) now offer V2X capabilities, including vehicle-to-grid (V2G), vehicle-to-home (V2H), and vehicle-to-load (V2L) features, allowing them to discharge power for various applications. Notable V2G-capable models include the Nissan Leaf, one of the earliest adopters with CHAdeMO, and newer CCS-equipped models like the Volkswagen ID.4, ID.5, and ID.Buzz, as well as the Polestar 3.

Other BEVs, such as the Hyundai Ioniq 5 and Kia EV6, support V2L only, letting users power small devices or appliances directly from the vehicle. As more automakers embrace V2X technology, vehicles like Ford’s F-150 Lightning and GM’s Silverado are extending the potential of BEVs beyond transport, enhancing grid resilience and offering backup power solutions. IDTechEx benchmarks various BEVs capable of V2X by capability, discharge rate, and charging standard in its report, “Charging Infrastructure for Electric Vehicles and Fleets 2025-2035: Markets, Technologies, and Forecasts”.

DC vs. AC V2G systems: understanding the options

There are two main approaches to V2X that differ based on the location of the inverter in relation to the vehicle and the charging point. The inverter can either be located internally within the EV so that the vehicle discharges in alternating current (AC) to the charger. Or externally to the vehicle and located within the charger so the vehicle discharges via direct current (DC).

DC V2G systems currently offer a higher discharge rate, typically ranging from 15 to 100 kW. These systems are mostly implemented through the CHAdeMO protocol and are characterized by lower vehicle power electronics costs. However, they come with a downside: higher infrastructure costs, as they require specialized DC charging equipment.

Looking forward: the future of V2G technology

As the number of V2G-capable BEVs grows, the potential impact on the grid could be substantial. IDTechEx expects the annual share of V2X (bidirectional) capable light-duty EVs sold to grow from 5% in 2023 to over 20% by 2028 in the US. By enabling widespread V2G adoption, EVs can contribute to a more resilient, flexible energy system. This vision, however, depends on collaboration across the automotive and energy sectors. Energy providers will need to develop dynamic pricing models and infrastructure that support V2G’s fluctuating energy demands, while vehicle manufacturers must continue developing affordable, V2G-compatible vehicles.

Heavy-duty vehicles such as buses, coaches, freight and construction vehicles, which have predictable usage patterns and downtime with high-capacity EV batteries, also provide good V2X potential. The North American market is already trialing this strategy with public school buses successfully. IDTechEx’s report on the charging infrastructure market analyses various V2X case studies to provide an overview of global projects.

With ongoing advancements and a commitment to standardization, V2G could soon become a mainstream feature, empowering EV owners to be active participants in the energy ecosystem.

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