Future-proof charging standards
ISO 15118 simply explained
With the transport turnaround, a major step has been taken to make eMobility future-oriented. In this technological and political process, it is also a matter of ensuring the networking of electric cars and charging options in the future. And this is where ISO 15118 comes into play - a communicative interface and series of standards between vehicles and charging stations.
What ISO 15118 is all about? Which electric cars are supported by the standard? What technology is behind it? What does Plug & Charge (PnC) mean? You can find out all this in the following guide.
The ISO 15118 standard on the one hand includes the standard communication to the vehicle via a PWM (standardised in IEC 61851-1), as it is integrated in every AC charging system today and which can only transmit rudimentary information. In addition to that, ISO 15118 also enables extensive communication via Powerline Communication (PLC) to the vehicle.
Modern electric cars mean that there is an extensive exchange of information that needs to be managed. To ensure this, the electric car industry has agreed to implement certain standards that make functions such as bidirectional charging (V2H & V2G) and the Plug & Charge method (PnC) as well as communication between the electric car and the charging station possible
Drive your e-car to the charging station, connect the car and the charging station with the cable: and you're done. Simply put, this is what is behind the new PnC function according to ISO 15118, which makes charging easy.
Using the ISO and the PnC method, an easy-to-use information exchange is created between the electric car and the charging station. Direct communication between the vehicle and the charging station means that neither the charging card (RFID chip cards) nor the app or QR code are needed as an intermediary and become obsolete, as the software behind them controls the entire process. ISO 15118 creates a uniform communicative standard, which greatly simplifies the identification of the e-car at the charging station and enables uncomplicated charging.
After a short registration of personal data, the electric car, the vehicle owner and the payment method are verified. In future, the electric car will be able to connect to the charging station independently using digital signatures and certificates after the electric car and charging station are connected with a charging cable. Charging is carried out automatically and the payment process is completed without further intervention.
At present, several vehicle models from the Volkswagen Group are already equipped for a PnC charging process at charging stations. With the decision to adopt ISO 15118, this smart charging function is expected to be used as a standardised method from 2025.
Another aspect of the ISO 15118 series of standards is the method of charging for electric vehicles and the electricity grid in both directions. These are the two methods Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G). In theory, there is a chance to stabilise an electricity grid that is confronted with high loads at certain times. Here, electric vehicles act as a kind of electricity storage unit that can transfer the electricity back into the grid via the charging station. In this way, unused electricity can be saved and used elsewhere.
Currently, there are still many technical, normative and legislative challenges, so that the development of a uniform standard may still take several years.
Bidirectional charging is said to have great potential and many advantages in various areas and use cases: This ranges from increasing self-demand optimisation and self-sufficiency in the private sector (Vehicle to Home: V2H) to the provision and use of balancing power and neighbourhood supply in the event of a blackout (Vehicle to Grid: V2G). Bidirectional charging is often seen as a key and important building block for the current energy transition.
On the one hand, this procedure works for V2H, whereby the unused electricity can be fed back into the power grid via the wallbox of the residential building. In this way, the private demand in the home can be partially covered. Vehicles with increased battery charging capacity could thus cover the demand for the entire household for several days.
The V2G method is also to be used in the future. Here, surplus electricity is transferred from the vehicle to the entire power grid. During periods of high load, this form of bidirectional charging would ensure that the electricity grid is relieved. In the future, electric car drivers could even be financially rewarded for implementing this variant of bidirectional charging. This will make driving an electric car more and more attractive from a financial point of view.