Experimental Validation of PV Module Modeling Based on Interpolation Approach in Outdoor Operating Conditions in the Southern Algerian Desert Regions

Modelling and extracting the characteristics of a photovoltaic (PV) panel are crucial aspects in researching and advancing PV systems. PV cell modeling needs to take into account the actual irradiance spectrum data for each location under practical working conditions. Unfortunately, the nonlinear nature of the panel model makes it challenging to solve with analytical methods. In this study, a mathematically simple approach called bilinear interpolation was presented and used to model and simulate the I-V curves of PV modules in order to translate the I-V curves under all given radiation and temperature conditions. Under the climatic circumstances of the Algerian desert, the modeling results by bilinear interpolation were examined and compared with the experimental results. Whereas, this modeling method was applied to three different module technologies: mono-crystalline (ET Solar-75W), polycrystalline (PHOTOWATT PW500), and thin film (QS Solar 60W). The results of the bilinear interpolation approach validation were very satisfactory. Furthermore, the method enabled us to obtain updated STC characteristics values after many years of PV panel use; as a result, the studied approach was one of the best methods for studying photovoltaic panel degradation.