*2.1. Electrical Installation Methods*

First, the different installation possibilities that can be used for the electrical installation of the BIPV system are briefly introduced. They are shown in Figure 1. In the string inverter approach (Figure 1a), several PV modules are series connected to form a string and are then coupled to the string inverter. Multiple strings are possible per inverter. The Maximum Power Point Tracking (MPPT) is done per string. A second option is the use of micro-inverters (Figure 1b) where one inverter is coupled with a single PV module. The MPPT is done per module, and the output is coupled directly to the AC grid. A third option is the use of series power optimizers (Figure 1c). There is again one converter per module, but the output is now DC instead of AC. The output ports of multiple converters are then series connected and coupled to a central inverter that regulates the DC bus voltage. The last option is the use of parallel power optimizers (Figure 1d). As with the series power optimizers, their output is DC. However, the DC voltage level is higher. They are parallel connected to the same DC bus, and the MPPT is also done per module. The different installation possibilities will be further evaluated for BIPV applications in Section 2.8.
