Abstract
Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. We describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without de-encapsulation. Peak power efficiency vs. light intensity was measured on a12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, we verified that cell shunt and seriesresistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. We discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.
Original language | American English |
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Pages | 1291-1294 |
Number of pages | 4 |
DOIs | |
State | Published - 1996 |
Event | Twenty Fifth IEEE Photovoltaic Specialists Conference - Washington, D.C. Duration: 13 May 1996 → 17 May 1996 |
Conference
Conference | Twenty Fifth IEEE Photovoltaic Specialists Conference |
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City | Washington, D.C. |
Period | 13/05/96 → 17/05/96 |
NREL Publication Number
- NREL/CP-22524