Assessment of prototype lightweight photovoltaic modules after over 1-year field test in Polish conditions

The compliance with international standards does not necessarily ensure a long-term reliability of photovoltaic modules. Field tests are required to make the standard tests more adjusted to the evaluation of new concepts. Numerous researches focus on long-term performance of standard modules, but only few studies are dedicated to lightweight modules. Therefore, the field operation of a PV system consisting of 28 lightweight modules of 4 different types (denoted as P1, P2, P3 and P4) has been being monitored for a year in warm temperate climate conditions. Over this period, the modules were tested by visual inspection, thermography and electroluminescence imaging and their electrical parameters were measured to compare results with the outcome of simulations in PVsyst. Visual inspections revealed yellowing and delamination of a few P2 and P4 modules because of issues with EVA foil. Thermography exposed many hot spots and failure of substrings in case of P2 modules. Also, the electroluminescence imaging showed numerous defects, mostly various micro cracks, which affected all modules' types. Nevertheless, excluding P2 modules, the others generated higher yield than estimated by the simulations. Analysing year-to-year degradation, results for P3 and P4 were in line with results predicted for standard PV modules in similar climates.