In conventional PV solar installations, solar panels are wired in series, creating a PV array. Central inverters, also known as String inverters are connected to multiple solar panels or the PV array, as shown in the figure below.
String or central inverters convert the high-voltage DC output from the PV array to alternating current (AC) so that it is easier to connect to the electricity grid.
In the microinverter architecture, a small inverter is attached to the back of each solar module. The output from several microinverters are connected in parallel, combined, and fed to the electrical grid.
A good inverter is usually judged mainly on the basis of two factors:
An efficient inverter, typically has an efficiency rating above 94%. While buying a car you look into its fuel consumption. Similarly while choosing a solar inverter you should see if it consumes low energy and has high efficiency.
Microinverters have several advantages over conventional central inverters:
While choosing between Microinverter and String inverter you have to consider your return on investment and pay back period. Microinverters are costlier than the conventional ones. Also since Microinverters have several high-tech electronic parts they are prone to failures. Though they may be suitable for shaded or complex roof, you have to decide if Microinverters give better returns and greater energy bill savings.