Photovoltaic Module Reliability. John H. Wohlgemuth
Task Group 7: Testing for Snow and Wind Load 7.8 Task Group 8: Testing for Thin‐Film Modules 7.9 Task Group 9: Testing for Concentrator Photovoltaic (CPV) 7.10 Task Group 10: Testing for Connectors 7.11 Task Group 11: QA for PV Systems 7.12 Task Group 12: Soiling and Dust 7.13 Task Group 13: Cells References
11 8 Conformity Assessment and IECRE 8.1 Module Conformity Assessment – PowerMark, IECQ, PVGAP, and IECEE 8.2 IECRE – Conformity Assessment for PV Systems References
12 9 Predicting PV Module Service Life 9.1 Determining Acceleration Factors 9.2 Impact of Design and Manufacturing on Failure or Degradation Rates for PV Modules 9.3 Impact of Location and Type of Mounting on Failure or Degradation Rates for PV Modules 9.4 Extended Stress Testing of PV Modules 9.5 Setting Up a True Service Life Prediction Program References
13 10 What does the Future Hold for PV and a Brief Summary 10.1 Current Work on Updating Standards 10.2 Looking to the Future 10.3 Brief Summary References
14 Index
List of Tables
1 Chapter 1Table 1.1 Process for making monolithically integrated thin film modules.Table 1.2 Typical commercial module constructions.
2 Chapter 2Table 2.1 Failure modes observed for c‐Si modules.Table 2.2 Linear thermal expansion coefficient of selected materials relevant...Table 2.3 Failure modes specific to thin modules.
3 Chapter 3Table 3.1 Process flow for usingaccelerated stress tests (ASTs) to improve mo...Table 3.2 Accelerated stress tests (ASTs) routinely used for PV modules.
4 Chapter 4Table 4.1 Qualification tests fromJet Propulsion Laboratory (JPL) block buys....Table 4.2 Properties ofJet Propulsion Laboratory (JPL) block buy modules.Table 4.3 History ofphotovoltaic (PV) module qualification tests.Table 4.4 Technology Specific Stabilization Parameters.Table 4.5 Solarex warranty period for crystalline silicon modules.Table 4.6 Required type of insulation for different classes of modules from I...Table 4.7a Minimum Creepage values for Class III modules.Table 4.7b Minimum Creepage values for Class III modules.Table 4.8a Minimum Creepage values for Class II modules rated for 1000 V.Table 4.8b Minimum Creepage Values for Class II Modules rated for 1000 V.Table 4.9 Minimum required distance through cemented joints.Table 4.10 Impulse voltage test levels from IEC 61730‐2.
5 Chapter 7Table 7.1 PVQAT task groups.Table 7.2 The seven cities used in Bosco study [16].Table 7.3 Weather characteristics for seven cities used as input to empirical...Table 7.4 Results of combined DH/PID stress test on four types of commercial ...Table 7.5 Comparison of calculated field diode maximum temperature for open r...Table 7.6 Comparison of calculated field diode maximum temperature for roof m...
6 Chapter 8Table 8.1 Published IECRE PV system certification documents.Table 8.2 Planned IECRE PV system certification documents [33, 34].
7 Chapter 9Table 9.1 Modeling of polyethylene terephthalate (PET) hydrolysis for open rac...Table 9.2 Equivalent temperature (°C) calculated for two module constructions...Table 9.3 Equivalent temperature (°C) calculated for two mounting configurati...
8 Chapter 10Table 10.1 Proposed current levels for testing in new edition of IEC 61215.Table 10.2 Voltage Stress Levels for insulation Test (MQT 03).Table 10.3 Proposed changes to IEC 61215 to take higher operating temperature...Table 10.4 Proposed changes to IEC 61730 to take higher operating temperature...Table 10.5 Temperatures of UV exposure conditions from IEC 62788‐7‐2.
List of Illustrations
1 Chapter 1Figure 1.1 Cross‐sectional drawing of screen‐printed cry‐Si solar cell.Figure 1.2 Cross‐sectional drawing of monolithically integrated thin film mo...Figure 1.3a Cross‐sectional drawing of glass/encapsulant/cry‐Si cells/encaps...Figure 1.3b Cross‐sectional drawing of glass/encapsulant/cry‐Si cells/encaps...Figure 1.3c Cross‐sectional drawing of flexible cry‐Si module.Figure 1.4a Cross‐sectional drawing of front glass/thin film cells/encapsula...Figure 1.4b Cross‐sectional drawing of front glass/encapsulant/thin film cel...Figure 1.4c Cross‐sectional drawing of module structures for thin film wafer...
2 Chapter 2Figure 2.1 Electroluminescence (EL) picture of module with multiple broken i...Figure 2.2 Magnified picture of interconnect ribbon with a crack [1].Figure 2.3 Electroluminescence (EL) picture of module with many broken cells...Figure 2.4 Cells with snail trails.Figure 2.5 Delamination over the Junction Box of the encapsulant from front ...Figure 2.6 Delamination between encapsulant and cell surface in Siemens Sola...Figure 2.7 Corrosion of the front metallization on solar cells [11].