String inverters are usually used when installing all modules on one roof surface. They are located at a central point in the home (such as the mechanical room) and are equipped with an MPP tracker. This ensures that the connected modules work efficiently as long as they are all exposed to similar conditions.
This type of inverter is not suitable if your photovoltaic modules are installed on differently oriented roof surfaces. In this case, either several string inverters or what are known as multi-string inverters are used for the PV system. The latter are equipped with multiple MPP trackers and ensure high efficiency even with different irradiation values.
Good to know: A string describes the totality of several individual photovoltaic modules connected in series.