In practice, however, this requires a high level of technical intelligence and the coordinated interaction of various technical components, both on the infrastructure side and in the vehicle. An Audi e-tron with near-series charging technology was used in the research project. In the test network, the all-electric Audi model operated with a DC wallbox, which enables a charging capacity of up to 12 kW, and a flexibly expandable home storage unit with a capacity of 9 kWh. In the event of possible series production use, this could provide additional flexibility, but is not a necessary prerequisite for bidirectional charging. Thanks to the DC voltage level in the overall system, the connection between the PV system and the vehicle does not require an inverter.
With bidirectional charging, the focus is primarily on use cases in which homeowners charge their own generated electricity with their own photovoltaic system in a cost-effective manner. At night, when electricity is cheap, the car is then charged again with cheap electricity until the desired target SOC (State of Charge) is reached.