The performance evaluation of the photovoltaic system is conducted by combining a theoretical power-estimation approach with environmental observations. The dataset includes irradiance, temperature, air density, and cloud cover, enabling examination of the system's operating conditions in relation to atmospheric variability. A reference power signal is obtained from a formulation dependent on temperature and irradiance intensity, and this signal is used as a reference for comparison with the measured output. From this reference point, residuals describing instantaneous deviations from expected behavior can be derived. These residuals are generally concentrated around zero. However, they are interrupted by distinct power drops at more infrequent intervals. These intervals are not randomly distributed over time. They coincide during periods when intense solar radiation coincides with high temperatures. This indicates that thermal effects and short-term radiation fluctuations jointly shape the observed response. To examine these effects, loss maps were created for light intensity-temperature and cloud cover-light intensity pairs. Ultimately, the most significant losses occurred when module temperatures increased alongside high radiation and under partially cloudy conditions. The study combined theoretical comparison, residue-based evaluation, and loss mapping. As a result, a new framework was presented to interpret PV performance deviations and understand how atmospheric variability leads to reductions in energy efficiency. The results indicate a cumulative loss of 54,663 Wh, corresponding to 26.62% of the total theoretical energy production. Residual magnitudes increased significantly under high irradiance conditions, often exceeding 200 W, highlighting the dominant role of combined thermal and atmospheric effects in shaping performance deviations.
Gökhan Yüksek (Fri,) studied this question.