Series resistance determination and further characterization of c-Si PV modules

This paper presents a new algorithm for determination of the series resistance of crystalline-Si PV modules from individual illuminated I–V curves. The ideality factor and the reverse saturation current are then extracted in the classic way. The approach is applied to in-situ measured data from modules based on two types of mc-Si feedstock. The results indicate that the method yields physically meaningful parameters. An improved definition of local ideality factor is suggested, resulting in m-V plots unaffected by the series resistance. In addition, m-I plots are introduced for the first time. The novel differential techniques reveal an unexpected rise of the ideality factor at open circuit by about 5%.

Graphical AbstractFigure optionsDownload as PowerPoint slideHighlights
► A new method for series resistance estimation for c-Si PV modules.
► Estimation from individual illuminated one-quadrant I–V curves.
► Ideality factors and reverse saturation currents for 2 types of SoG-Si.
► Formulation of local ideality factor corrected for series resistance.
► Ideality factor rises by 5% at open circuit!