Residential PV battery systems can be distinguished in the connection of the battery between DC and AC coupled
systems, as illustrated in Fig. 1. In AC coupled systems the battery is connected to the PV system, which consists of
the PV generator and inverter, via a charge regulator and a battery inverter. In contrast, DC coupled batteries are
connected to the DC link of the PV inverter. In this study, AC coupled residential PV battery systems are
considered. The modelling of the system components is described in the following.
It is assumed that the PV generator is south-oriented with a tilt angle of 35°. Therefore, the measured irradiance
on the horizontal plane has to be converted to the plane of array. This is done geometrically for the direct irradiance
and with the model suggested by Klucher for the diffuse irradiance [4]. Considering the reflectance of the
environment with an albedo of 0.2, an annual sum of the irradiation on the PV generator of 1233 kWh/m² was
determined.