Testing vehicle-to-grid technology with 700 EVs in Germany
New generation electric cars are built assuming a dual function for batteries: accumulating energy for vehicle traction and dedicating charge to the grid when the vehicle is stationary and already at 100%. The V2G, Vehicle-to-Grid functionality, has long been discussed as an option that can contribute to the stability of the energy infrastructure, due to the ever-increasing number of electric cars in circulation.
The most advanced European country in this experimentation appears to be Germany, where 700 vehicles have been used to test the injection of electrical energy stored in BEV batteries into the grid. This pioneering project precedes the large-scale deployment of V2G technology. German operator TransnetBW and British energy supplier Octopus have partnered to conduct a field trial called project OctoFlexBW.
The project aims to test the feasibility of using the storage capacity of electric vehicle batteries to contribute to balancing the electricity grid, in exchange for compensation for owners. Already launched in June 2024, it has gradually expanded to include a growing number of vehicles, which has now reached the number of 700 volunteers.
Less than 3 kWh drawn from each battery
According to an initial assessment, the fleet would have already mobilized a daily capacity of approximately 2 MWh over a year, equivalent to about 2.86 kWh drawn on average from each vehicle’s battery. A modest figure on this small scale, but one that heralds the significant potential of V2G. If we hypothesized the use of one million vehicles, no less than 3 GWh could be fed into the grid.
Three phases of the Vehicle-to-Grid project
Charging processes were programmed so that vehicles were fully charged in the morning and in the most cost-efficient way possible. The project is divided into three phases, each building upon the previous one.
– Phase 1 focuses on technological connection for communication
– Phase 2 tests the target process for communicating flexibility potential using planning data.
– Phase 3, over 1,500 BEVs can be activated in a standardized and largely automated way when redistribution is needed, thus concretely contributing to the grid control process.
In addition to the activation system, a balancing solution fully compliant with energy sector standards has been integrated. Initial data confirms the vehicles’ readiness to respond to grid signals; for instance, night charging is modulated or suspended precisely to alleviate the load during critical periods.
Vehicle-to-grid perspectives: from pilot project to market application
The subsequent project, “DataFleX”, aims to further expand this approach, involving over 1,000 vehicles and integrating additional flexible solutions such as home battery storage systems. In the future, heat pumps could also be integrated. An adequate regulatory framework is now crucial for widespread adoption.