Comparative Study of Power Prediction for Photovoltaic Modules with Different Technologies Tested in Italy and in Spain

The performance of photovoltaic (PV) modules can be assessed using several models, with the most common being the Osterwald model, which states PV power is proportional to solar irradiance. However, the models based on electrical equivalent circuits, which have a variable number of parameters affected by environmental conditions like irradiance and temperature, can be used to increase the accuracy of PV power estimation. Actually, understanding these parameters in any weather condition can help predict PV generators’ performance with higher accuracy than commonly used analytical models. This work is inserted in a research field aiming to develop a model for the automatic diagnosis of PV plants by their inverters based on the equivalent circuit’s parameters. This study compares the application of a method for evaluating PV power based on the single diode model to PV modules tested at two different installation sites. The devices under test are 7 modules, tested in Turin (Italy) and Jaen (Spain), with different technologies, rated power (up to 370 W) and efficiency (up to ≈21%). The accuracy of such a technique is validated by comparing the power estimation by such a methodology with that of the Osterwald model.