More Charging Power Than the Grid Connection Can Provide: Battery-Buffered Microgrid Unlocks New Potential for Fast Charging

As part of a master’s thesis at the Technical University of Applied Sciences Ingolstadt, a public fast-charging site at Bayernwerk’s headquarters in Regensburg was analyzed over several weeks under real operating conditions. The results provide practical insights for the expansion and operation of modern charging infrastructure.

The setup included three fast-charging systems: two conventional hyperchargers with 150 kW and 50 kW charging power, as well as one ChargePost from ADS-TEC Energy featuring an integrated 201 kWh battery storage system and up to 300 kW charging power. The entire site operates on a grid connection of just 125 kW.

For conventional fast chargers, this would represent a clear bottleneck, as their charging power directly depends on available grid power. The ChargePost, by contrast, decouples charging power from the grid connection: despite requiring only 22 to 87 kW of input power, the system can deliver up to 300 kW charging power. The additional energy is supplied by the integrated battery storage system.

Within the microgrid, the ChargePost takes on a dual role: it not only charges connected vehicles, but also supports the additional charging points during periods of high demand and compensates for peak loads. This allows multiple vehicles to charge simultaneously despite the limited grid connection.

System integration is another key factor. The ChargePost can be integrated into existing energy and building management systems and centrally controlled. This makes it possible to combine high charging performance, cost efficiency, and grid-friendly operation.

This creates clear economic benefits for operators. The need for costly grid expansion can be significantly reduced or even avoided entirely. At the same time, the system enables high vehicle throughput even at locations with limited grid capacity.

The field test showed particularly strong results in the economic optimization scenario: by reducing peak loads and purchasing electricity at favorable times, operating costs in the analyzed case were reduced by several thousand euros per year.