Photovoltaic Module Reliability. John H. Wohlgemuth

2.8 Corrosion on corner of glass–glass module [11].Figure 2.9 Corrosion of cells in Polyvinyl butyral (PVB) Module [12].Figure 2.10 Example of discolored Ethylene Vinyl Acetate (EVA) formulation A...Figure 2.11a Characterization of unexposed module.Figure 2.11b Characterization of module after 10 years of field exposure in ...Figure 2.12 Example of single point solder bond failure on bus bar [1].Figure 2.13 Example of Multiple Solder Bond Failures on One Cell [20].Figure 2.14 Module with tempered glass broken by impact.Figure 2.15 Module with tempered glass broken due to overheating at bad sold...Figure 2.16 Breakage of an annealed glass thin‐film module [20].Figure 2.17 Junction box that has moved from its mounting position.Figure 2.18 Backsheet exhibiting cracking after outdoor exposure. [3].Figure 2.19 Glass breakage due to hot spot in module [22].Figure 2.20 Maximum cell temperature as a function of reverse current measur...Figure 2.21 IR pictures of heating effects and the formation of hot spots du...Figure 2.22 Picture of failed diodes.Figure 2.23a Two modules of same type undergoing snow load testing [29]. Mod...Figure 2.23b Two modules of same type undergoing snow load testing [29]. Mod...Figure 2.24 Snow damaged modules hanging from their support structure by ele...Figure 2.25 Snow load damage to module.Figure 2.26 Arc caused by an open circuit within a junction box.Figure 2.27 Module with ground fault to frame arc [11].Figure 2.28 Array fire caused by ground faults in the installation system....Figure 2.29 Electrochemical corrosion of TCO in a‐Si module [32].Figure 2.30 Electroluminescence (EL) picture of module after Potential‐Induc...Figure 2.31 Hot spot in monolithic, thin‐film module after field exposure [1...Figure 2.32 Hot spot in discrete cell, thin‐film module after field exposure...Figure 2.33 Edge seal failure in field exposed thin‐film module [11].

      3 Chapter 3Figure 3.1 Accelerated testing of a chicken egg.

      4 Chapter 4Figure 4.1 Picture of representative samples of Module from each of the Jet ...Figure 4.2 Accelerated stress test sequence from the first edition of IEC 61...Figure 4.3 Summary of accelerated stress test sequence from IEC 61215: 2016....Figure 4.4 Module I‐V characteristics with different cells totally shadowed ...Figure 4.5 Module I‐V characteristics with the one of the four selected cell...Figure 4.6 Four wire set‐up for the bypass diode thermal test.Figure 4.7 Accelerated stress test sequence from the second edition of IEC 6...Figure 4.8 Layout of ten peel test strips for peel test.Figure 4.9 Construction of lap shear samples for lap shear strength test.

      5 Chapter 5Figure 5.1 I─V curve of typical PV module.Figure 5.2 Electroluminescence (EL) picture of cell with a crack that remove...Figure 5.3 Corrosion in thin film cells that removes active cell area.Figure 5.4 Equivalent circuit of a solar cell.Figure 5.5a Effect of series resistance on I─V curve, arrow is in the direct...Figure 5.5b Effect of shunt resistance on I─V curve, arrow is in the directi...Figure 5.6a I─V curves as a function of irradiance for one of the CIGS modul...Figure 5.6b I─V curves as a function of irradia...Figure 5.6c I─V curves as a function of irradiance for one of the triple jun...Figure 5.7 Efficiency as a function of irradiance for CIGS, CdTe and a‐Si Tr...Figure 5.8 Performance Ratio versus Irradiance for two modules from each arr...Figure 5.9 Fill Factor versus Irradiance for same module set.Figure 5.10 Dark I─V curves for same module set.Figure 5.11 Infrared (IR) image of broken interconnect ribbons (see arrows)....Figure 5.12 Infrared (IR) picture of hot spot in thin film module [10].Figure 5.13 Optical picture of bus tape delamination in thin film module [10...Figure 5.14 Electroluminescence (EL) picture of cells with cracks caused by ...Figure 5.15 Electroluminescence (EL) picture of damaged cry‐Si module. Black...Figure 5.16 Electroluminescence (EL) picture showing cell with missing grid ...Figure 5.17 Electroluminescence (EL) picture of module showing some cells wi...Figure 5.18 Electroluminescence photographs of a cry‐Si module after extende...Figure 5.19 Electroluminescence (EL) picture of a thin film module after eig...

      6 Chapter 6Figure 6.1 Degradation rates for PV modules (and arrays) reported in the lit...Figure 6.2 Modeling of humidity present within the back side of a glass/poly...Figure 6.3 Long‐term damp heat testing (85/85) results [9].Figure 6.4 Results of analysis for the humidity level in the EVA located bet...Figure 6.5 Results of analysis for the humidity level in the EVA located bet...

      7 Chapter 7Figure 7.1 Pareto chart of module field failures [3].Figure 7.2 Power loss as a function of thermal cycles [9].Figure 7.3 Accumulated damage within the solder bonds in one year in the sev...Figure 7.4 Comparison of damage to solder bonds calculated using finite elem...Figure 7.5 Number of thermal cycles required to cause damage equivalent to o...Figure 7.6 Delamination of ASE Module over the junction box.Figure 7.7 Delamination in siemens solar module.Figure 7.8 Delamination between encapsulant and cell after DH/PID stress tes...Figure 7.9 Change in transmittance with radiant exposure (H) for the coupons...Figure 7.10 Comparison of change in transmittance with applied temperature f...Figure 7.11 Xenon weathering performed at 80 °C and 30% relative humidity....

      8 Chapter 9Figure 9.1 Hours per year module will operate at given temperature for glass...Figure 9.2 Module level tests for qualification plus [20].

      Guide

      1  Cover

      2 Table of Contents

      3  Begin Reading

      Pages

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