Photovoltaic Module Reliability Workshop 2011
February 16–17, 2011
The Photovoltaic (PV) Module Reliability Workshop was held in Golden, Colorado, on Feb. 16–17, 2011. The objective was to share information to improve PV module reliability because such improvements reduce the cost of solar electricity and give investors confidence in the technology. The U.S. Department of Energy (DOE) Solar Energy Technologies Program (Solar Program) sponsored the workshop.
The following documents are available as Adobe Acrobat PDFs. The entire proceeding of the PV Module Reliability Workshop can be downloaded (ZIP 146 MB).
In addition, a detailed agenda is available.
The presentations are grouped by topic and session:
- Overview Presentations
- Plenary Session A: Diagnostics of Failed and Degraded Modules
- Plenary Session B: Methodologies for Performance, Reliability, and Durability Determination
- Plenary Session C: Upstream Materials, Module Components, and Standards
- Plenary Session D: Customer Experiences with Modules and Balance of Systems
- Concentrating PV Issues Session
- Crystalline Silicon Issues Session
- Thin-Film Issues Session
- Poster Session.
This following presentations provided attendees with a summary of the workshop and reliability research that is supported by the Solar Program.
- Welcome, Peter Hacke, PV Module Reliability Workshop Chair, National Renewable Energy Laboratory (NREL)
- Workshop National Center for Photovoltaics (NCPV) Welcome, Ryne Raffaelle, NCPV Director, NREL
- Opening Remarks and Overview of DOE Solar Program, Kevin Lynn, Systems Integration Lead for the DOE Solar Program
Plenary Session A: Diagnostics of Failed and Degraded Modules
Sarah Kurtz, NREL, and Jim Sites, Colorado State University, chaired this session on PV diagnostics of failed and degraded modules.
- Degradation Mechanisms in Si Module Technologies Observed in the Field; Their Analysis and Statistics, David DeGraaff, Ryan Lacerda, Zach Campeau (SunPower Corp)*
- Building for 25-year Durability in Amonix Solar Power Plants, Geoffrey S. Kinsey (Amonix)
- Thin Film Module Reliability-Enabling Solar Electricity Generation, Markus Beck, Pedro Gonzalez, Richard Gruber, Jim Tyler (First Solar)
* Best in Workshop Award
Plenary Session B: Methodologies for Performance, Reliability, and Durability Determination—Baby Steps Toward Determination of a 25-Year Warranty
Kenneth Sauer, Yingli Green Energy Americas, and Michael Quintana, Sandia National Laboratories (SNL), chaired this session on PV methodologies for performance, reliability, and durability determination.
- How to Set Up a Reliability Program for Photovoltaic Modules, Harry Guo, Athanasios Gerokostopoulos (ReliaSoft Corporation), Ryan Gaston (Dow Chemical)
- From Climate Data to Accelerated Test Conditions, Michael Kohl (Fraunhofer Institute for Solar Energy Systems)
- Monitoring System Performance, Keith Emery, Ryan Smith (NREL)
- Methods for Analysis of Outdoor Performance Data, Dirk Jordan (NREL)
Plenary Session C: Upstream Materials, Module Components, and Standards
Kaitlyn VanSant and David Miller, both of NREL, chaired this session on PV upstream materials, module components, and standards.
- IGMA 25 25-Year Field Correlation Study, A. William Lingnell (Lingnell Consulting Services)
- Physical Properties of Glass and the Requirements for Photovoltaic Modules, James E. Webb, James P. Hamilton (Corning)
- Reliability and Durability Evaluation of PV Connectors, Mani G. TamizhMani (Arizona State University)
- Durability Testing for Module-Attached Micro Inverters, France Antelme (Enphase Energy)
- How Standards Control Module Design for Better or Worse, John Wohlgemuth (NREL)
- Safety Concerns with New PV Polymeric Materials, Crystal Vanderpan (Underwriters Laboratories Inc.)
Plenary Session D: Customer Experiences with Modules and Balance of Systems
Jennifer Granata, SNL, and Neelkanth G. Dhere, University of Central Florida/FSEC, chaired this session on PV customer experiences with modules and balance of systems.
- An Owner's View: The Role of PV Reliability in Financing, Operations and Performance, Hugh Kuhn (Solar Power Partners, Inc.)
- PV Reliability and Performance: A Project Developer's Experience, Bradley Hibberd (Borrego Solar Systems)
Concentrating PV Session
Sarah Kurtz, NREL, Steven Seel, Semprius, Peter Hebert, Spectrolab, Nick Bosco, NREL, Ian Aeby, Emcore Solar Power, and Geoff Kinsey, Amonix, Inc., chaired this session on technology-specific issues related to concentrating PV (CPV).
- What Not To Do, Peter Hebert, John Frost, Rob Cravens, Robyn Woo (Spectrolab)
- Modeling Thermal Fatigue in CPV Cell Assemblies, Nick Bosco, Dhananjay Panchagade, Sarah Kurtz (NREL)
- Low Concentration Photovoltaics: Reliability and Durability Issues, Roger H. French (Case Western Reserve University)
- Reliability Testing Of High-Concentration PV Modules And Soiling Issues, Michael Winter, Greg Flynn, Jim Foresi, Phil Blumenfeld, Rick Hoffman, Ian Aeby, Theo Romero (Emcore)
- CPV Solar Cell Qualification Standard, Ian Aeby (Emcore)
- Minimizing Variation in Outdoor CPV Power Ratings, Matthew Muller (NREL)
- CPV Rating Standards Development, Sarah Kurtz, Sandheep Surendran, Pierre Verlinden, Francisca Rubio, Kenji Araki (NREL)
- Acrylic Materials in PV Applications: Making an Informed Choice, Peter Colburn (Evonik Industries)
Discussion summary for CPV sessions:
- Some cell failure mechanisms can be mitigated (for example, by use of strain relief, by avoiding halogen contamination, and by avoiding location-dependent thermomechanical fatigue). Testing for lifetime prediction will involve thermal and moisture cycling as well as light and electrical bias, although different CPV designs make standardized testing challenging.
- CPV needs a broad spectrum of standards development to address operation lifetime, not just infant mortality.
- A consensus decision on test conditions for energy and power ratings of CPV modules is close, but requires fine tuning of spectral and optical correction factors.
Dan Doble, Fraunhofer CSE, Dave Degraaff, SunPower Corporation, Govindasamy (Mani), TUV Rheinland PTL, and Michael Köhl, Fraunhofer ISE, chaired this session on technology-specific silicon issues.
- Origin and Consequences of (Micro)-Cracks in Crystalline Silicon Solar modules, M. Köntges, I. Kunze, S. Kajari-Schröder (Institute for Solar Energy Research Hamelin ), X. Breitenmoser, B. Bjørneklett (REC Solar AS)
- Systematic Investigation of Crack Development and Crack Growth in Embedded Crystalline Solar Cells under Thermal and Mechanical Loads, Sascha Dietrich (Fraunhofer CSP)
- Potential Induced Degradation, William Richardson (Solon Corporation)
- High Voltage Bias Testing of Specially Designed c-Si PV Modules, Neelkanth G. Dhere, Shirish A. Pethe, Ashwani Kaul (Florida Solar Energy Center)
- Failure Modes and Degradation Rates from Field-Aged Crystalline Silicon Modules, Tony Sample (European Commission, DG JRC, Institute for Energy, Ispra, Italy)
- Analysis of Hot Spots in Crystalline Silicon Modules and their Impact on Roof Structures, Daniel W. Cunningham (BP Solar)
- PV Module Arc Fault Modeling and Analysis, Jason Strauch (Sandia National Laboratories)
Discussion summary of for crystalline silicon sessions:
- There is now better understanding of how cracks propagate in PV modules and a quantitative understanding of how different cracks affect power.
- Sodium migration affects PV module durability and a variety of environmental factors affect module leakage current. There remains a need to understand the relationship between indoor stress testing and outdoor degradation for the mechanisms of c-Si module degradation under system bias.
- Resistive heating in modules does not cause fires, but conductor gaps lead to arcing, which can potentially start fires.
Ryan Gaston, Dow Chemical Company, and Samuel Graham, Georgia Institute of Technology, chaired this session on technology-specific issues related to thin films.
- Goals and Strategies for Moisture-Hardening the CIGS Device, I. Repins, F.J. Pern, R. Sundaramoorthy, N. Bosco, T. Gennett, J. Perkins, S. Christensen, A. Dameron, L. Simpson, J. Del Cueto S. Glick, A. Goodrich, M. Woodhouse, T. James (NREL)
- Life Prediction for CIGS Solar Modules, D.J. Coyle, H.A. Blaydes, R.S. Northey, J.E. Pickett, K.R. Nagarkar, R.A. Zhao, and J.O. Gardner (GE Global Research)
- Systems Approach to High Performance CIGS Material Set Including Flex Ultra-Moisture Barrier and Hi-Temp MLI Substrate, K. W. Leffew, S. Boussaad, D. Reardon, H. Tate, N. Glassmaker, D. Dean, G. Nunes, S. L. Samuels, J. Schneider, P. Carcia, R. Mclean (Dupont Research & Development)
- Durability of Ultra Barrier Solar Films for Flexible PV Applications, Mark Roehrig, Mark Weigel, Tracie Berniard, Alan Nachtigal, Bill Murray (3M)
- Calcium Based Test Method for Evaluation of Photovoltaic Edge-Seal Materials, Michael Kempe, Arrelaine Dameron, Matthew Reese (NREL)
- Reliability and Application Challenges for Flexible Thin-Film (BIPV) Modules, Samir Sharma, Doug Herron (United Solar Ovonic LLC)
- Intrinsic Chemical Instability and Metastability in Photovoltaic Devices, Angus Rockett (University of Illinois)
- Analysis of Alternate Methods to Obtain Stabilized Power Performance of CdTe and CIGS PV Modules, J. del ueto, C. Deline, S. Rummel (NREL)
Discussion summary for thin-film sessions:
- There is validation of edge-seal performance models for determining thin-film device lifetimes, along with general advancement of models for determining the lifetime of CIGS modules.
- There is a need for QC tools for vapor barrier films.
- There are numerous tests for acceleration of failure modes for BIPV applications, but codes and standards need development.
- There are options to account for module metastability, but further understanding of mechanisms and kinetics of metastability is required.
Organizations that did not give oral presentations were required to contribute at least one poster to stimulate discussion. Because every organization contributed, a wealth of information was available to participants. The poster session included a wide variety of presentations grouped by the following topics:
- Quantify Degradation Rates and Mechanisms of PV Modules and Systems Installed in Florida Through Comprehensive Experimental and Theoretical Analysis, Nicoleta Sorloaica-Hickman, Kris Davis, (Florida Solar Energy Center -UCF), Sarah Kurtz, Dirk Jordan (NREL)
- Why Leveraging 'Industry Standard Components' Is Not as Simple as It Sounds, John Fulton (Skyline Solar)
- Estimating the Degradation Rate of Photovoltaic Arrays Using a Two Component Nonlinear Model, Christopher Gotwalt (SAS Institute)
- Requirements for a Standard Test to Rate the Durability of PV Modules at System Voltage, Peter Hacke, Kent Terwilliger, Steve Glick, Michael Kempe, Sarah Kurtz (NREL), Ian Bennett, Mario Kloos (ECN, Petten)
- Plextronics OPV Outdoor Testing, Min Xiao, Mike Pannone, Darin Laird (Plextronics), Eric Karplus (Science Wares, Inc.)
- Photovoltaic DC Arc-Fault Circuit Protection and UL Subject 1699B, Tim Zgonena, Liang Ji, Dave Dini (Underwriters Laboratories Inc.)
- Photovotaic Modules EDF EN Quality Control, Khalid Radouane, Pierre-Guy Therond (EDF Energies Nouvelles), Francoise Evin, Didier Binesti (EDF R&D)
- Statistical Modeling of Photovoltaic Reliability Using Accelerated Degradation Techniques, J. Lee, R. Elmore, & W. Jones (NREL)
- The Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems, David C. Miller, Michael D. Kempe, Cheryl E. Kennedy, Sarah R. Kurtz (NREL), Kenji Araki (Daido Steel Co., Ltd.)
- Linking Accelerated Laboratory and Outdoor Exposure Results for PV Polymeric Materials, Xiaohong Gu, Kaipeng Liu, Tinh Nguyen, Joannie W. Chin (NIST)
- Reliability of SOG for CPV Primary Optics, Steve Scott, Edward Philips (Reflexite Corporation), Stefan Gaebler, Maik Jacob, Juergen Zosel, Martin Bitzer (Fresnel Optics GmbH)
- PV Arc Fault Detector Challenges Due to Module Frequency Response Variability, Jay Johnson, Scott Kuszmaul, Jason Strauch, Ward Bower (Sandia National Laboratories)
- CPV Module Acceptance Angle Characterization, Sandheep Surendran (Surya Design)
- Perforance of a Low-Cost, Low-Concentration Photovoltaic System, K.A. Shell, S.A. Brown, M.A. Schuetz (Replex Plastics), R.J. Davis (Nanotech West Lab, Ohio State University), R.H. French (Materials Science, Case Western Reserve University)
- ACRYLITE® Acrylics for Reliable Long-Term Performance, Evonik Industries
- On the Development of Accelerated Aging Tests Based on Thermal Stress Impact to Assess the Reliability of 1000 Suns CPV Modules, G. Fleury, S. Colasson, T. Baffie, M. Mariotto (CEA-LITEN), J.L. Martin, C. Mangeant, L. Mabille (INES), J.E. De Salins (HELIOTROP SAS)
- Correlations in Characteristic Data of Concentrator Photovoltaics, Cassi Sweet, NREL
- NICE Modules Certification According to IEC-61215 and 61730, J. Dupuis, E. Saint-Sernin, K. Bamberg, R. Einhaus, (Apollon Solar), E. Pilat, A. Vachez (CEA-INES), D. Bussery (Vincent Industrie)
- Mechancial Issues on Solar Modules and Encapsulated Components, M.Ebert, S. Dietrich, M. Pander, R. Meier, S.-H. Schulze (Fraunhofer - CSP)
- Outdoor Weathering of c-Si PV Modules in Various Climates - Measurement and Transfer of Module Data of PV-Modules Via GPRS, Nicolas Bogdanski, Werner Herrmann (TÜV Rheinland Energie und Umwelt GmbH)
- Progress on e-Modules Research and Production, Genmao Chen, Shawn Qu, Jiang Peng, Xusheng Wang, Wenda Zheng (Canadian Solar Inc.)
- Development of a New Standard for Transport Simulation on Complete PV-Module Shipping Units in Combination with Thermo-Mechanical Stress, Jörg Althaus, Florian Reil, Konstantin Strohkendl, Nicolas Bogdanski (TÜV Rheinland Energie und Umwelt GmbH)
- Volume Resistivity of EVA Encapsulant Sheet, Tsuyoshi Shioda (Mitsui Chemicals, Inc.)
- Reliability Factors for Salvage Value of Photovoltaics, Joseph McCabe (SMUD Salvage Sales )
- Material Considerations for Crystalline Silicon PV Module Backsheets, Honeywell
- Automated Extraction of Cell Parameters in a Fully Packaged Solar Module, G. B. Alers, J. Olsen, N. Green (APV Research, University of California)
- Durability Test of Poly-Ethylen-Terephthalate (PET) Film for Backsheet, Kusato Hirota, Masanori Miyashita, Takao Amioka (Toray Industries, Inc.)
- Junction Box Qualification at REC Solar, Frøydis Oldervoll, Børge Bjørneklett, Teck Cheng Tan (REC Solar)
- Study on Anti-reflection Coated Glass for Photovoltaic Modules, Tony Tang, Suntech Power Co., Ltd.
- PV Standards. What Does the IEC Have for You?, Howard Barikmo, Sunset Technology, Inc.
- Comparison Between Outdoor Performances and Manufacturers' Flash Test Results of Crystalline Si PV Modules, Yuzuru Ueda, Kosuke Kurokawa (Tokyo Institute of Technology), Mitsuru Kudo and Hiroo Konishi (NTT Facilities, Inc.)
- Study on Anti-reflection Coated Glass for Photovoltaic Modules, B. Yin, Y. Tang, G. Wang, J, Liu, R. Gao, Q. Guo, J.Wen, G. Zhang (Suntech Power Co., Ltd.)
- Qualification and Lifetime Testing Protocols for Gen II Back Contact Solar Cells/Modules, Bethanne Felder, Sonya Xu (Applied Materials)
- Characterization and Aging Study of Encapsulant (EVA) and Backsheetfor PV Modules, Shuying Yang, Abhay Maheshwari, Shirish Shah, Junaid Fatehi, Kent Whitfield (Solaria)
- Demonstration of the Benefits of Silicone Encapsulation of PV Modules in a Large Scale Outdoor Array, Barry Ketola, Chris Shirk, Philip Griffith, (Dow Corning Corp.), Gabriela Bunea (SunPower Corp.)
- Evaluation and Analysis of 15 years Exposure PV module, Yoshihito Eguchi (SHARP)
- PV-Integrated Microinverters in High-Reliability Rooftop Applications, T. Paul Parker (SolarBridge Technologies)
- Damp Heat Testing Longer than IEC Standards, Mike Van Iseghem, Antoine Plotton, Didier Binesti , Khalid Radouane, Pierre-Guy Therond (EDF)
- Improvement of Reliability Using Four Bus Bar Cell, Masashi Nakamura (Mitsubishi Electric Corporation)
- Developments in Weatherable Polyester Films For Photovoltaic Applications, William J. Brennan, Simon J. Shepherd (DuPont Teijin Films)
- Effect of Temperature on the Response of PV Modules to Mechanical Stress, Rafal A. Mickiewicz, John Lloyd, Matthias Winter, Adam Stokes, Dab Doble (Fraunhofer USA)
- Silicone Yellowing Due to Material Interaction in a CPV Application, Steve Seel, Wolfgang Warner, Scott Burroughs (Semprius)
- Multi-Crystalline Silicon Solar Cell Modules: Crack Formation and Development Due to Climate Chamber Thermal Cycle Testing, A.F. Dethlefsen (SCHOTT Solar AG)
- Photovoltaic Module Certification, Reliability Testing and Failure Analysis at Jabil, Vivek Gade, David Cook and Philip Capps (Jabil Photovoltaic Certification and Testing Laboratory)
- New Acceleration Test for PV Modules Such as Burns or Interconnector Failures, Takuya DOI (AIST)
- Solar Module Logistics Current Packaging Methodologies and Considerations, Herb Schueneman (Westpak, Inc.)
- Prediction of Critical Module Hot Spots Caused by Shunts in Silicon Solar Cells Using In-Line Thermography, Chris Stapelmann, Robert Fritz (SolarWorld Industries America), Fabian Fertig (Fraunhofer ISE), Benjamin Weiss (Oregon State University)
- Advanced Fluoropolymer-Free, High-Grade PET-Based Backsheet Reaching Over 3,000 Hours DHT*, M. Vannini, A. Palazzo (COVEME) , T. Surek (Surek PV Consulting)
- Accelerated Test and Statistics Model Analysis of Degradation Performance for PV Module Lifetime Prediction, Yi-Hung Chou, Shih-Yu Huang, Rong-Sheng Cheng, Kuei-Chang Fan, Chung-Chin Lee (Delsolar Co., Ltd.), Yao-Tung Hsu, Yi-Ru Hsu, Cheng-Ban Chung, (Institute of Nuclear Energy Research), Chien-Yu Peng (Institute of Statistical Science), Sheng-Tsaing Tseng, Chi-Chun Tsai (National Tsing-Hua University), Ethan Wang, Carl Wang (Underwriters Laboratories Taiwan Co., Ltd.)
- Sensitivity of PV System Degradation Rates to Data Filtration, Kenneth J. Sauer (YINGLI Solar)
- Fast and Reproducible Test Method to Investigate Hot-Spot Sensitivity of c-Si Solar Cells, B. Jaeckel, J. Novak, R. Won, A. Krtschil (Q-Cells SE)
- Fast and Reproducible Test Method to Investigate Hot-Spot Sensitivity of c-Si Solar Cells, B. Jaeckel, J. Novak, R. Won, and A. Krtschil (Q-Cells SE)
- LightSwitch™ ETFE Frontsheet, Robert Pleydon, N. Bhiwankar, Phoebe Kwan, Jessica McCoy (Northboro & Worcester Research & Development Center)
- c-Si PV Thresher Test, Alelie Funcell, Renewable Energy Test Center, RETC LLC
- Accelerated Weathering Testing Principles to Estimate the Service Life of OPV Modules, O. Haillant, Kurt P. Scott (Atlas Material Testing Solutions)
- From Rigid to Flexible: The Real Challenge of CIGS Module R&D, A. Reithe (Solarion AG/Institut Aufbau- und Verbindungstechnik), M. Munch, M. Meisner, S. Tegen, K. Heger (Solarion Ag), M. Wachsmuth (Solarion AG/Hochschule Mittweida, University of Applied Sciences)
- A Decade of Combined Cycle Accelerated Testing, Stefan Jarnason (CSG Solar Pty Ltd)
- Five Stages of a Solar Cell, Paul Lamarche (Solar Junction)
- MicrosoftHigh Moisture Barrier Flexible Front Sheet for CIGS, O. Akaike, T. Aya, N. Ninomiya, Y. Mitsukura, S. Kanai (Mitsubishi Plastics Inc.)
- Product Reliability Challenges Due to Packaging in A-Si Thin Films Modules, Deepak Shivaprasad (Novasolar Technologies)
- Light Soaking Effects on PV Modules: Overview and Literature Review, Michael Gostein, Lawrence Dunn (Atonometrics, Inc.)
- An Edge Sealing "Getter" Tapefor Ultra-long Lifetime (up to 3000 hours) of Thin Film CIGS PV Modules, A. Bonucci, R. van der Wel, P. Gallina, M.Amiotti (SAES Getters SpA), S. Hiss (Kuraray Europe GmbH), O. Salomon, W. Wischmann (ZSW Stuttgart)
- Electroluminescence to Track Cell and Module Changes from Small-Area Cells to Large-Area Modules, M. Topic, M. Bokalic (University of Ljubljana, Slovenia), K. Zaunbrecher, J.R. Sites (Colorado State University)
- Highly Accelerated Weathering of CIGS Photovoltaics, J. Cole Rickers, D. Garth Jensen (Ascent Solar Technologies, Inc.)
- Stress Testing and Failure Analysis Methods for Determining the Reliability of Metal Buss Tapes, Jason Hevelone, Michelle Propst, Chris Richardson (Abound Solar)
- Performance and Reliability Characterization of Conductive Inks for Solar Cell Front Grids and Busbars, D.W.J. Harwood, S. Agaskar (D2Solar), S. Pirzada, S. Coughlin, L. Nguyen (AQT Solar)
- Temperature Study on a-Si:H Solar Cell Degradation with Different Loading Conditions, Sang Hyun Park, Yong Sun Kang, Jun-Sik Cho, Jeong Chul Lee, Kyung Hoon Yoon (Korea Institute of Energy Research)
- Accelerated Ageing and Reliability of CIGS Thin Film Solar Cells, Raymund Schaffler (Wurth Solar GmbH & Co KG), T. Walter, P. Mack, T. Ott (University of Applied Science, Ulm)
- Energy Production Comparison of Four Representative Solar Cell Technologies: mc-Si, a-Si, CIGS and OPV, Richard Childers (Konarka), Elsa Kam-Lum (Total S.A.)
- Keeping the Water Out for 25 Years, Ondine Suavet (Nanosolar)
- Solar Attachment Adhesives for Building Applied Photovoltaic (BAPV) with Superior Bond Strength, Tim O'Neil, Samar Teli (ADCO Products Inc.)
- Effect of Long-Term Light Soaking on Shunts and Pmax in CIGS Solar Cells and Modules, A. Kamer, S. Jayanarayanan, N. Staud, D. Nayak, B. Metin, E. Lee, M. Pinarbasi (Solopower)
- Strategies for Developing Barrier Films For Photovoltaics, Yongjin Kim, Hyungchul Kim, Namsu Kim, Samuel Graham (Georgia Institute of Technology)
- Understanding Degradation Pathways in Organic Photovoltaics, M. T. Lloyd, D. C. Olson, A. Garcia, N. Kpidakis, M. O. Reese, J. J. Berry, D. S. Ginley (NREL) and I. Kauvar (Materials Science and Engineering)