Where conversion happens
A string-inverter system sends DC power from one or more module strings to a central inverter. A microinverter system converts power at or near each module. The architecture changes where MPPT, monitoring and service points sit.
Shading and roof complexity
Module-level electronics can reduce the extent to which one module’s operating conditions influence others, but system design still matters. String systems can also use multiple MPPT inputs, optimizers or carefully separated roof planes.
Service and replacement
A central inverter is usually easier to access at ground level, while a failed roof-mounted microinverter may require rooftop service. On the other hand, a single microinverter failure does not necessarily stop the rest of the array.
Battery and backup architecture
Do not choose an inverter architecture in isolation if storage is planned. Confirm the supported battery, backup topology, transfer equipment and commissioning requirements for the exact product family.
Compare complete installed systems
Ask for the exact equipment list, layout, monitoring features, warranties, service responsibilities and expected production assumptions. Compare total scope rather than one headline component price.