A Parametric Approach for Estimation of PV Short-Circuit Current

Accurate modeling of short-circuit current (Isc) in photovoltaic (PV) modules is crucial, predominantly impacted by solar irradiance and cell temperature. It is also significantly affected by the spectral distribution of incoming solar radiation, which is often overlooked in standard performance models. The Sandia model (SAPM) incorporates an empirically fitted spectral mismatch factor (SF) while more complex methods use spectral irradiance models that require extensive computations. This study proposes a novel alternative approach that applies parameterized atmospheric transmittances for modeling Isc, aiming to maintain the accuracy of spectral methods while enhancing computational efficiency and accessibility. The model utilizes a minimal set of atmospheric parameters and a module-dependent correction factor, easily derived from the catalog sheet standard test conditions for Isc. The proposed method focuses on horizontally placed crystalline silicon PV modules, under clear-sky conditions. The model yields good results, matching the spectral integration method (using SMARTS2 simulated spectra) with an R² of 0.99. Validation against data collected during a clear-sky day in June 2023 at the Solar Platform of the West University of Timisoara, Romania, showed the proposed model achieved a normalized root mean square error (nRMSE) of 1.3%, outperforming the spectral method (4% nRMSE) and the standard method (4.4% nRMSE).