The subsidiary of the Chinese state-owned company SAIC Maxus has successfully tested bidirectional charging for the fully electric transporters eDeliver 5, eDeliver 7 AWD, and the electric all-wheel-drive pickup eTerron 9 in collaboration with specialist Ambibox. In the future, the E-Vans could not only receive power but also return it to buildings or the public power grid as needed—this is known as "bidirectional charging." This allows the energy from the vehicle battery to be actively utilized when the vehicle is parked and connected to a suitable charging solution. Both the vehicle and a technically compatible wall box or charging station are required for this. Applications of bidirectional charging: Besides Vehicle-to-Load (V2L), which is already standard in some Maxus models, there are several other use cases for bidirectional charging.
- Vehicle-to-Home (V2H): It is obvious to use the
- power from the vehicle battery to increase the self-consumption rate of a PV system. For this purpose, electricity is stored in the battery when the PV system produces more than is needed in the house. When the power demand is higher than the production of the PV system, the battery releases electricity. This usage is called Vehicle-to-Home (V2H) or Vehicle-to-Building (V2B).
- Vehicle-to-Grid (V2G): Another interesting form of use is called Vehicle-to-Grid (V2G). The battery of the electric vehicle is used to regulate power supply and demand in the local distribution grid through intelligent charging: E-cars are charged when electricity demand and therefore usually the electricity price is low; conversely, they feed electricity back into the distribution grid during times of high demand and correspondingly high prices. This use case makes particular sense with a large
- number of vehicles, for example, in a fleet that is charged at a depot.
Focus on Standardization
Bidirectional charging via the CCS plugs, which are set as the standard in Europe, is currently possible with only a few charging stations. Specialist Ambibox offers a certified, compatible charger according to the DC standard with a charging capacity of up to 22kW. The tested vehicles are fully compatible with this system, taking another step towards a market-ready introduction. The SAIC subsidiary sees solid economic advantages in bidirectional charging for both private and fleet customers. If a private customer increases the self-consumption rate of their own PV system through bidirectional charging (V2H or V2B), they can save money immediately since the electricity from their own roof is generally cheaper than that from the public grid. This can
also apply to the fleet operator if the vehicle depot is located at a warehouse or distribution center and the electricity demand can be partially met from the vehicle batteries.
Grid-Responsive Charging is Profitable
The so-called "grid-responsive charging" (V2G), where electricity from vehicle batteries is fed back into the grid to cushion demand peaks in the public power grid, is seen as the economically most attractive use case. The grid operator is willing, within the framework of a contractual agreement, to compensate for this "fed-back" electricity. This possibility for monetization has the potential to significantly reduce the Total Cost of Ownership (TCO), as the costs for charging the vehicle batteries are counter-financed by income. Currently, the manufacturer is working on introducing this technology to the market in Europe, aiming to offer added value through intelligent, bidirectional
