Photovoltaics Reliability

Photovoltaics Reliability

PV-1 Study of the Potential-Induced Degradation Kinetics

J. Bengoechea, M. Ezquer, J. Diaz, A.R. Lagunas, National Renewable Energy Centre

A dedicated set-up which allows a real-time characterization of the PV modules, while being subjected to the Potential-Induced Degradation (PID) test, was developed and tested. This real-time characterization includes the measurement
of the dark I/V curve and the acquisition of electroluminescence (EL) images at different biasing levels. By means of this realtime characterization it is possible to early identify the PID presence and its kinetics during the total duration of the test.This set-up allowed the investigation of the influence of salt as an impurity in module packaging with regard to PID. To this aim, a mini-module contaminated with salt including on the surface of one of its solar cells and in the glass-EVA interface was laminated. This mini-module showed an increased susceptibility to PID, which developed also in the uncontaminated solar cells. Repetitions of the PID test showed that its influence diminished with the number of cycles.

PV-2 Potential Induced Degradation in High-Efficiency Bifacial Solar Cells

M. Barbato, M. Meneghini, A. Cester, A. Barbato, G. Tavernaro*, M. Rossetto*, G. Meneghesso, University of Padova, *MegaCell S.r.l.

This paper presents an analysis of the degradation of Bifacial Solar Cells submitted to potential induced degradation (PID) stress. We report the results obtained on cells with two different encapsulation materials: ethylene-vinyl-acetate (EVA) and polyolefin elastomer (POE). Results show that the use of different encapsulation materials may result in a better robustness towards PID in Bifacial Solar Cells.

PV-3 Improvement of DSSC Performance by Voltage Stress Application

A.Scuto, G. Di Marco*, G. Calogero*, I. Citro*, F. Principato**, C. Chiappara**, S. Lombardo,, CNR IMM, *CNR IPCF, ** Università degli Studi di Palermo

Dye-sensitized solar cells (DSSCs) are promising third generation photovoltaic devices given their potential low cost and high efficiency. Some factors still affect DSSCs performance, such structure of electrodes, electrolyte compositions, nature of the sensitizers, issues of power conversion efficiency and stability under prolonged electrical cycles, etc. In this work we discuss the effect of electrical stresses, which allow to improve DSSC performance. We have investigated the outcomes of forward and reverse DC bias stress as a function of time, voltage, and illumination level in the DSSCs sensitized with the N719, Ruthenium complex based dye. We demonstrate that all the major solar cell parameters, i.e., open circuit voltage (VOC), short circuit current (ISC), series resistance (ROC), fill factor (FF), and power conversion efficiency are strongly influenced by the stress conditions and a clear reversibility of the parameters on the stress type is shown. In this context we examined the possible effects that emerge from the electrolyte composition. Our study suggests that under proper biasing the DSSCs noticeably improve in terms of efficiency and long-term stability.

PV-4 Adhesion Requirements for Photovoltaic Modules of Polymeric Encapsulation

J. Zhu, G. Surier, D. Wu, D. Montiel-Chicharro, T. Betts, R. Gottschalg, Longborough University

This paper addresses the delamination issue and investigates the adhesion requirement and failure of packaging material at the different interfaces. Lamination condition has significant impacts on the adhesion stability and failure modes, which will be further investigated too.