Since 2006, the observed taxi fleet is equipped with GPS devices for purposes of operation and routing. From this GPS data the relevant transport characteristics are extracted and the feasibility of taxi ranks as locations for charging infrastructure will be examined. By the means of three selectable parameters "battery capacity", "charging power" and "charging stations expansion", various scenarios are defined, which are examined in subsequent analyses using load flow and mathematics software.

The basic requirement for the further considerations is the fulfilment of the mobility needs of taxis. Based on these necessities and frameworks the additional charging profiles at the taxi ranks with charging infrastructure are calculated and the impact on the distribution grids related to voltage stability and overloads is investigated. In order to make a qualitative statement, the current household and commercial electricity loads are identified through long-term measurements.

By using simplified thermal models a temporary overloading of electrical grid components is considered. These temporary overloads allow the supply of a strong electric taxi penetration requiring minimal grid expansion and may be acceptable if the effects on the individual components are negligible.

If the overloads for the electric distribution grid cannot be tolerated, grid oriented charging strategies are developed in order to avoid grid extension. As a consequence, it must be shown that the adapted charging profiles do not negatively impact the fulfilment of the mobility needs.

The results and knowledge of the project ZENEM allow the distribution grid operator to avoid unnecessary expansion of grid infrastructure. In the last phase of the project, a workshop was held on the ecological and economic aspects and frameworks with experts from the energy, transportation and political sector.