Accuracy investigation in the modeling of partially shaded photovoltaic systems

Abstract

Software for simulation of photovoltaic (PV) systems is widely used for dimensioning and forecasting electrical production. A factor of losses in PV installations is the partial shading caused by surrounding elements, and these software allow the user to estimate this effect. However, the accuracy of these simulated results for shaded PV systems is not widely studied. The purpose of this article is to investigate the accuracy and quantify the differences between simulated and measured data of partially shaded PV systems, obtained with the widely used tools SAM and PVSyst. Measured data from a PV installation were compared to results from simulations performed using the different shading calculation options available in both tools. The simulated outputs were both underestimated and overestimated in the shading situations. This variation was related to the use of an hourly fraction of shading and, in the case of SAM, due to the limitations of the 3D tools available for representation. Another source of differences between simulated and measured values was the use of uniform shading factors for diffuse and albedo. In addition, the simplification of the 3D model had a significant impact on the predicted energy, mainly on cloudy days. Both software overestimated the electricity production for the entire measurement period, reaching differences between the predicted and the measured energy varying from 9% to 24%. Shaded PV systems must be carefully analyzed, and the simulated results may differ from the measured values, which may even influence the decision on the feasibility of an installation.

Monitoramento de sistemas fotovoltaicos utilizando diferentes bases de dados de radiação solar e temperatura

“…In the case of PV systems in urban areas, the systems have complex surrounding elements that make it difficult to estimate some of these parameters, such as the albedo, in addition to these elements causing shading. The complexity of estimating input parameters and modeling shaded systems were analyzed by Chepp, Gasparin e Krenzinger (2021).…”

Investigation of Near Shading Losses in Photovoltaic Systems with PVsyst Software

“…The analyses in this study were performed with the PVsyst simulation software, which is widely used in industrial and educational fields. PVsyst software is frequently used in studies on determination PV potential of various regions [26,27], in the design and performance analysis of grid-connected or standalone PV power plants [28,29], and in the analysis of shading events [30,31]. The PVsyst 7.4 [32] software produced by PVsyst SA was used in the designs and simulations made in the present study.…”

Monitoramento De Um Sistema Fotovoltaico Utilizando Bases De Dados De Radiação Solar E Temperatura Do Inmet

“…No caso de sistemas FV em meio urbano, os sistemas possuem elementos de entorno complexos que dificultam a estimativa de alguns desses parâmetros, tais como o albedo, além desses elementos causarem sombreamento. A complexidade da estimativa de parâmetros de entrada e da modelagem de sistemas sombreados foram analisadas por Chepp, Gasparin e Krenzinger (2021).…”