Microinverter and string inverter grid-connected photovoltaic system — A comprehensive study

This paper present a comparison between a string inverter based photovoltaic (PV) energy system and a microinverter based system. Reliability, environmental factors, inverter failure, and electrical safety of a test case 6kW residential PV system are thoroughly evaluated and compared using the two different approaches. The impact of all these features on the cost of the PV system is estimated. The results showed that when the levelized cost of energy (LCOE) is considered the break-even cost can be reached by the microinverter more quickly than with a string inverter operating in the same environment Moreover, considering the replacement costs associated with the expected string inverter failure, the microinverter configuration is the more cost effective.