On the Karlsruhe Institute of Technology (KIT) campus, researchers are starting to examine the integration of electric vehicles into intelligent energy grids. Car OEM Adam Opel has provides a number of test vehicles, the electric edition of the Meriva.

The vehicles are equipped with a bidirectional electronic unit designed to enable users to charge their batteries from normal 230V household outlets as well as from 400V three-phase outlets. The designers aimed at particularly low charging times of less than an hour. In addition, the control unit communicates with the energy provider and charges the battery only at times when energy gained from regenerative sources such as solar power or wind power is cheap. At times of the day when electric energy throughout the (smart) grid is in high demand, the car can feed back a part of the electricity stored in its battery into the grid.

Opel's e-Meriva is equipped with a relatively small battery which offers a capacity of 16 kWh – certainly not the type that users can expect in future volume e-cars, but sufficient for the MeRegioMobil trials.

The electric vehicles belong to what KIT calls a “smart home”, equipped with the usual electric appliances of a household. It can generate energy by means of a photovoltaics installation on the roof and a small combined heat and power station. “The project gives us the opportunity to examine chances and challenges of the integration of e-cars into the energy grid in an interdisciplinary cooperation,” explained researcher Hartmut Schmeck. The KIT professor added that currently no other vehicle offers the option to feed electric energy into the grid. “This feature can be regarded as a potentially stabilizing factor for the grid. However, its potential can only be tapped by the intelligent deployment of information and communication technologies to be developed in this project”.

Thus, the development of communication technology required to connecting vehicles and grid is another focal point of the project. Another subproject touches the development of a billing system.

The project also anticipates other elements of a smart charging infrastructure: The energy providers participating in the project plan to install several hundred charging station across the state of Baden-Wuerttemberg. They plan to establish a kind “roaming” system similar to what is already established in mobile telecommunications. This system would enable car users to charge their vehicle at any charging station, independently of which energy provider operates the station.