Full characterization of photovoltaic modules in real operating conditions: theoretical model, measurement method and results

The photovoltaic (PV) system performance essentially depends on the modules response to five effects: spectral, reflection, temperature, irradiance, and nominal power variations. Providing a full characterization of modules behavior in terms of the impact of these effects on real operating conditions performance is very important both to compare different PV technologies and to choose the best technology for a specific site, position, and installation feature. In this work, a systematic approach is used. A theoretical model to calculate the performance ratio related to each effect is proposed. The model is used to compare and to explain the annual behavior of two different technologies: a multicrystalline silicon module (mc-Si) and a double junction amorphous silicon module (a-Si/DJ). The basic features of these modules performance are observed.