Comparing output and efficiency of central inverters and micro-inverters, with micro-inverters the overall output and efficiency is increased due to the fact that every micro-inverter / panel unit acts independently. Therefore, when one panel is shaded it does not affect the rest of the array, providing maximum production. While with a central inverter, when one panel is shaded, the output of the entire system is reduced to the output of the lowest producing panel.
Micro-inverters usually come with a manufacturer’s warranty of 25 years. With a central inverters, although they might be a little less expensive in the beginning, normally they have only a 10 manufacturer’s warranty and soon afterwards stops working and need to be changed out. This means the whole system will be down and not producing any electricity during that time.
With micro-inverters, Monitoring and maintenance is also easier as many micro-inverter producers (e.g. Enphase) provide apps or websites to monitor the power output of their units.
Power optimizers may sound similar to micro-inverters, but they are not. The power optimizer uses only a “central” inverter for the entire array, which means a single point of failure that can cause a complete shutdown of the array. As for the warranty, the standard is 12 years (13 years less than that of a micro-inverter).