Germany is one of the nations firmly committed to a renewable energy future. Already more than 20 percent of the nation’s power is produced from solar and other renewable sources. Being able to efficiently utilize those sources is part of the issues that must be addressed. According to an article on, the country has more than 2,000 electric car charging spots. At the largest, at Fraunhofer Institute Center Stuttgart IZS –up to 30 electric vehicles at a time can re-charge at AC charge spots in the campus parking garage. There is also one DC fast charging spot that has a charging capacity of up to 50 kilowatts and can fully charge a car’s battery in just 20 minutes.

To get that kind of simultaneous power output requires state-of-the-art smart grid technology and load management. Daimler AG and the Institute for Human Factors and Technology Management at the University of Stuttgart, IAO scientists are developing both the charging infrastructure and the energy management in a project called charge@work. Their aim is to design a micro smart grid (MSG) capable of supplying the EV fleet with electricity produced exclusively from renewable sources. The MSG will be DC power based, to avoid the losses that occur when transforming alternating current (AC) into DC.

The ultimate goal of the project is to combine the micro smart grids into a large smart grid for EV charging. Over the next two years, the MSG innovation network will provide interested parties with an opportunity to work up new kinds of smart grid configurations and operating strategies.