A method for operating an inverter and an inverter configured to convert DC power supplied from a DC power source into AC power supplied to an AC network by applying maximum power point tracking, MPPT, such that a harmonic content of an AC current supplied from the inverter to the AC network is kept within a predetermined maximum level, wherein during the converting the inverter is configured to detect a need to increase the harmonic content of the AC current supplied from the inverter to the AC network beyond the predetermined maximum level, perform a check whether an increase of the harmonic content of the AC current beyond the predetermined maximum level is allowed, and, if an increase of the harmonic content of the AC current beyond the predetermined maximum level is allowed, raise the predetermined maximum level used in the converting.