I-V curves of a PV string under two different partial shading conditions are shown. The red areas (forbidden areas) include the I-V curve points that cannot be reached by a hypothetical inverter due to its voltage and current constraints. The PV string working point can only be set by the inverter in the green area (operating area). In orange, an I-V curve traced when more than 50% of the modules are shaded (or dirty); in blue, an I-V curve traced when the shading (or soiling) involves less than 50% of the modules. It can be pointed out that in the case of the orange curve, the current value I*, measured in correspondence with the minimum voltage of the inverter, is lower than the correct I_sc value. Instead, in the case of the blue curve, the value of I* coincides with I_sc.