In a small-scale, most likely residential, installation, the pv- module has to be connected to an Invertor
The purpose of an inverter is to :-
- Change the direct current (DC) output of a solar module to an alternating current (AC), which is used by all appliances.
- Transform the voltage from the module's voltage to voltage required.
In small-scale installations the AC output from the inverter is a 2-phase AC, which is common in households. The inverter output can be connected to the grid via a meter.
Maximum Power Point Tracker (MPP)
As the MPP- tracker ensures that the module operates at its maximum power point at all times. Most inverters also include the maximum power point tracker (MPP). Where crystalline modules are used, partial shading of the entire roof (for instance caused by a tree or the chimney), the module will only generate as much current as its weakest string. In this instance, each string should have its own MPP- tracker, resulting in efficiency gains of up to 8% according to . described Stecc
Some inverters may also provide surge protection. However, this may not be enough if the wires between the solar module and the inverter are longer than 10m, when additional surge protection devices ought to be considered.