When owners of electric cars regularly charge their cars at home, this poses new challenges for the household mains. After all, it is vital that charging the car does not overburden the mains. And where a photovoltaic system is installed on the roof, the power it generates also needs to be included in the relevant calculations.

A new open source software takes on these problems. On the one hand, openWB ensures that the total power supported is not exceeded when owners charge their car battery. On the other, it can configure the Wallbox (WB), i.e. the charging station, in such a way that it primarily utilizes the power from a photovoltaic system. To this end, the software accesses the household’s current meter data and calculates how much electricity can be spared for the Wallbox. It also ensures that the solar power is used in the most effective way.

The developer, 30-year-old computer scientist Kevin Wieland from near Fulda, offers openWB together with the necessary hardware as a kit for around €400. A mini Raspberry Pi computer is used for the calculations. Wieland urges, however, that only electricians should assemble the kit and connect it to the relevant meters.