With the number of electric cars on the roads increasing every day in Germany, the need for more flexible charging infrastructure and methods is also growing. The use of decentralised renewable energy generators with stationary battery storage built for this purpose could also contribute to the stabilisation of the grid.

Convention has it that electric cars are mainly charged after work or overnight, which can cause load peaks in the power grid at these times. But energy bottlenecks could be avoided if the entire idle time of the vehicle (which is estimated on average at 23.25 hours a day) could potentially be used for charging, for example in corporate parking lots.

In the “SKALE” research project which began in January 2021, the Karlsruhe Institute of Technology (KIT) has teamed up with commercial partners Robert Bosch GmbH and Power Innovation Stromversorgungstechnik GmbH to develop a scalable, direct current (DC) charging system based on photovoltaic (PV) power generation, lithium-ion battery storage and a medium voltage connection to the grid.

“The new approach is intended to provide a forward-looking infrastructure solution for any parking area with a large number of charging points and to efficiently integrate decentralised energy sources,” says Professor Marc Hiller of KIT’s Electrotechnical Institute (ETI) in a press release.

A demonstration model is to be set up with 10 charging stations, PV systems with 100 kilowatts at peak and battery storage of 50 kilowatt hours. Within the project’s scope, a suitable converter will be built for connection to the medium voltage grid.The team at KIT will also develop a design tool that can optimise charging infrastructure including applications and components tailored to specific locations. SKALE has been funded with EUR 4.3 million by the Federal Ministry for Economic Affairs and Energy.