Photovoltaic (PV) technology has become increasingly an important source of energy. In PV systems, the inverter is a crucial device. Hence, it can be employed in different structures to build the PV plant and to improve the system performance. In this paper, the minimum Levelized cost of electricity (LCOE) is computed by the proposed optimization process for comparison purpose between the most used topologies for PV plants, central and string structures. Two cases with nominal power limit of 100 kWp and, no power limit using all PV plant area are considered. As results, PV plants with central layout present lowest LCOE with limited nominal power and with no limit compared to string mode. Additionally, the sensitivity analysis prove that by increasing the inverter efficiency, the PV plant LCOE decreases.