Will single-family homes need no power connection anymore in the future? This is what our xHouse project is designed to reveal. The residential house has been equipped with a photovoltaic system, an electricity storage battery and a bi-directional charging pole which is designed not only to charge an electric car but also to discharge it so as to use the electricity in the house if needed. A Home Energy Management System (HEMS) takes care of the interplay of all the components and optimises the energy flows. The energy manager controls the power supply from the in-house storage battery, the battery of the electric car, the solar system and the grid. It responds flexibly to the energy demand in the house, the volume of the currently generated solar power, the charging level of the batteries and the charging requirements of the car.
The solar system provides electricity which can be consumed directly by the customer. Surplus electricity will be stored in the battery of the house or of the electric car. If the level of consumption in the house is particularly high, self-generated, stored green electricity is used as required. The car with the bi-directional charging system provides another option to optimise the energy flows. This minimises the customer’s electricity costs and reduces the load on the grid.
Apart from the self-sufficient supply with no grid access, the xHouse project is also supposed to investigate the optimum design of the systems and to explore options of using the concept also in office buildings or car parks.