The promotional images are the same, always send charging electric cars in front of elegant single-family homes. However, of the 40.8 million homes, which the Federal Statistical office reported at the end of 2018 in Germany, there are 21.7 million in multi-family houses with at least three residential units. And since the Overnight Charging of an electric car can be a Problem. Not always a private Parking space is available. And even if the apartment block has an underground car Park, is the Installation of a private Wallbox is not readily possible. Although the Federal government no longer wants to adopt after the parliamentary summer break, a new law, therefore, has to be a unanimous decision of the owners ‘ meeting is mandatory, to a charging station to connect. Still, a technical hurdle remains: in an underground garage with 20 Parking places in a top together would be a load of more than 200 kilowatts, if all the vehicles are loaded after the return from the office at the same time an AC Wallbox. A common house connection is overwhelmed quickly, as well as the Ortnetztrafo and the supply end of the cable.
A pilot test of the distribution network operator, Netze BW in Tamm, a small town in the Stuttgart suburbs, to show that it is. Under the 2012-built residential complex “Pura Vida” with 63 residential units, an underground Parking garage with 85 Parking spaces, of which 58 with a charging point equipped is located. This corresponds to the Two-thirds rate, the battery electric cars and Plug-in could achieve in Hybrids in 2030, according to estimates of experts the number of new registrations. To seduce the apartment owners to Participate, represents EnBW, a total of 45 battery-electric BMW i3 and VW e-Golf available. “The goal of the project is to analyze the actual user behavior and to check, based on our assumptions about the resulting network load,” explains project Manager, Ralph Holder. “We also want to find out how far controlling interventions to be accepted.”
The cost for the electrical upgrade of the underground garage was significant. From about 200 meters away Ortnetztrafo the network operator moved two cables each with a diameter of 95 mm to the Cabinet in the Garage that was secured on an output of 124 kW. A separate storage battery, which can be a maximum of bunkers 36 kilowatt-hours of electricity, feeds here. For comparison: The separate house connection point has an output of 286 kW. In addition to the control Cabinet is the heart of the Installation: the adjustable power distribution is controlled from the from the charging points. The latter are, in principle, only from a holder for the plug and the supply line. The residents authorize the Plugging of the charging cable with a transponder chip at a Terminal.
