Extraction of thermal model parameters for field-installed photovoltaic module

Performance of PV-system strongly depends on climate variables. In less favourable climate conditions, as in Central Europe, highly varying radiation is very frequent. In such consitions, the accurate energy yield predictions from PV-systems require more accurate thermal modelling, than simple industry-standard approach based on single NOCT parameter. The paper demonstrates the method for extraction of parameters for simple RC-thermal model from measurements of field-installed photovoltaic module. The calculated RC-thermal time constant allows to recognize the climatic conditions requiring careful thermal modelling. Moreover, in order to satisfy the simplicity of PV-simulations, as an alternative to the RC-model, the idea of simplified approach to handling variable radiation conditions has also been proposed.