Bi-directional charging at the Baumwollspinnerei

Challenge / Goal

The electricity flow of the highly innovative Bi-Directional charging stations for e-mobility allows great potential for electricity grid resilience. The grid frequency for electrical networks of all sizes must be stable. To achieve grid stability, the amount of electrical energy in the grid should remain as constant as possible. This becomes increasingly challenging with variable renewable energy sources such as wind and solar, as they are weather-dependent and can only be forecasted with limited accuracy. At the same time, the complexity of electricity consumption is increasing as more and more electrical appliances are used in everyday life, as well as in the industrial sector. 

For this reason, it is necessary to integrate storage capacities into new and existing grid structures. Storage systems can supply the grid with electricity as the circumstances require. Electricity can be temporarily stored if the amount of electricity in the grid is too high and the storage can supply the grid with electricity, should the grid frequency drop. In this regard, bi-directional charging offers the ability to transform electric vehicles from mere energy consumers into temporary storage systems. Digital communication (the so-called charge management) between the vehicle and the charging station initiates the charging or discharging of the battery, depending on the situation.

The core challenge of this concept, however, lies in its innovative nature, there are no sufficiently defined European standards, neither in the technical nor in the economic sectors. Consequently, the technical compatibility of different vehicle models and charging stations in Europe is not available yet. Furthermore, there are no established billing models that, for example, compensate for the wear and tear on the car battery, caused by charging and discharging processes and that integrate the calculation of taxes and duties in a legally secure manner.