Modeling and Outdoor Characterization of Two Thin-Film Photovoltaic Modules: A Case Study of a-Si and Cigs Modules in a Semi-Arid Climate Zone

Reliable modeling of photovoltaic (PV) module performance under field conditions is important for optimizing system design. This study evaluates two promising thin-film technologies, an amorphous silicon (a-Si) 5W module and copper indium gallium diselenide (CIGS) 7W module, under Baghdad’s semi-arid climate over six months. Outdoor current-voltage and power-voltage curves were measured at irradiation levels of 500-1000 W/m2 and module temperatures of 25-50°C. A validated five-parameter model was used to simulate module performance. At 1000 W/m2 irradiation and 25°C, measurements showed maximum power outputs of 4.05W and 7.11W for the a-Si and CIGS modules respectively. The model predicted these values within 5% (3.9W) and 4% (7.37W). Model errors were below 10% for all test conditions. Specifically, at 500 W/m2 and 50°C, measured powers were 1.75W (a-Si) and 3.11W (CIGS), while modeled outputs were 1.8W and 3.07W respectively. This analysis provides a comprehensive long-term experimental dataset and accurate modeling of these thin-film technologies under real Middle Eastern operating conditions. It can aid optimization of PV systems based on these promising thin-film technologies