Influence of Shunt Resistance on the Performance of an Illuminated String of Solar Cells: Theory, Simulation, and Experimental Analysis

This paper presents an extensive study of how a solar cell with low shunt resistance can affect the performance and reliability of a solar panel. The analysis is based on both simulations and experimental tests and provides the following results: 1) the cell with low shunt resistance significantly reduces the efficiency of a panel; 2) this is particularly pronounced if the shunted cell is partially shaded: in this case, the shunt resistance of the cell acts as a load for the entire panel; 3) in these conditions, the shunted cell can significantly degrade: in fact, the small-size shunt paths are crossed by a high current density, generated by the other cells in the panel, thus reaching high temperature levels. Stress tests have been also carried out to fully characterize the degradation process and its dynamics and to understand the physical origin of the failure of shunted cells.

[1]  Method of extraction and analysis of solar cell parameters from the dark current-voltage curve , 2005, Conference on Electron Devices, 2005 Spanish.

[2]  K. Bucher,et al.  Reverse characteristics of commercial silicon solar cells-impact on hot spot temperatures and module integrity , 1997, Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997.

[3]  G. Meneghesso,et al.  Effect of shunt resistance on the performance of mc-Silicon solar cells: a combined electro-optical and thermal investigation , 2012, 2012 38th IEEE Photovoltaic Specialists Conference.

[4]  Thomas Basso,et al.  Cell shunt resistance and photovoltaic module performance , 1996, Conference Record of the Twenty Fifth IEEE Photovoltaic Specialists Conference - 1996.

[5]  E. Radziemska.  Dark I–U–T measurements of single crystalline silicon solar cells , 2005 .

[6]  O. Breitenstein,et al.  CLASSIFICATION OF SHUNTING MECHANISMS IN CRYSTALLINE SILICON SOLAR CELLS , 2002 .

[7]  Gaudenzio Meneghesso,et al.  Thermal and electrical investigation of the reverse bias degradation of silicon solar cells , 2013, Microelectron. Reliab..

[8]  Stephan Großer,et al.  Shunt Analysis in Solar Cells - Electro-Optical Classification and High Resolution Defect Diagnostics , 2012 .

[9]  Ronnie Belmans,et al.  Partial shadowing of photovoltaic arrays with different system configurations: literature review and field test results , 2003 .

[10]  E. Meyer,et al.  The effect of reduced shunt resistance and shading on photovoltaic module performance , 2005, Conference Record of the Thirty-first IEEE Photovoltaic Specialists Conference, 2005..

[11]  R. Gottschalg,et al.  Modelling shading on amorphous silicon single and double junction modules , 2003, 3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of.

[12]  Alain Fave,et al.  New method of parameters extraction from dark I-V curve , 1997, Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997.

[13]  E. V. Dyk,et al.  Parameter extraction from dark current-voltage characteristics of solar cells , 2008 .