SciELO - Scientific Electronic Library Online

vol.26 número3Low-income resident's preferences for the location of wind turbine farms in the Eastern Cape Province, South AfricaA perspective on South African coal fired power station emissions índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados



Links relacionados

  • En proceso de indezaciónCitado por Google
  • En proceso de indezaciónSimilares en Google


Journal of Energy in Southern Africa

versión On-line ISSN 2413-3051
versión impresa ISSN 1021-447X


CROZIER, Jacqui L; VAN DYK, Ernest E  y  VORSTER, Frederick J. Identification and characterisation of performance limiting defects and cell mismatch in photovoltaic modules. J. energy South. Afr. [online]. 2015, vol.26, n.3, pp.19-26. ISSN 2413-3051.

The performance and longevity of photovoltaic (PV) modules can be severely limited by cell mismatch occurring when a solar cell in a series-connected string produces a lower current than the other cells in that string. The current output of the entire string is limited by the weakest cell in the string so shading or damage to a single cell in a module can affect the entire module's current output. Electroluminescence (EL) occurs when a positive current and voltage are applied to a solar cell and is used to identify damage and defects in the cell. In this study, the cell mismatch in three single crystalline silicon modules was investigated using EL and current-voltage (I-V) characterisation techniques. Two modules have a white discolouration that affects the majority of the cells in the module and also have signs of mechanical damage, while the third module acts as a reference as it has no discolouration and appears undamaged. The EL signal intensity is related to cell performance and identifies material defects, bad contacts and broken cells. Cell mismatch in a module results in a decrease in the performance parameters obtained from the I-V characteristic curve of the module. The I-V curves indicate the presence of current mismatch in the degraded modules, which is supported by the EL images of these modules. The use of EL images, in conjunction with the I-V curves, allows the degradation in the modules to be characterised.

Palabras clave : photovoltaics; cell mismatch; current-voltage characterisation; electroluminescence; degradation.

        · texto en Inglés     · Inglés ( pdf )


Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons