An experimental procedure to check the performance degradation on-site in grid-connected photovoltaic systems

Recently, high feed-in tariffs and low PV module prices have permitted huge amounts of installed power plants. Sometimes, rapid design and installation have generated poor performance in grid-connected PV systems. In this paper the proposed procedure suggests some rules for minimizing poor performance in the energy production. The first phase is to test the arrays of PV modules on-site. The second phase is to test only the PV strings or single modules belonging to arrays with poor performance. The third step is to use the thermo-graphic camera and the electroluminescence at PV-module level. The fourth step is to monitor the DC racks of each inverter or the individual inverter, if equipped with only one MPPT. Experiments results on a real PV system show the effectiveness of this procedure.