Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following an equivalent year of testing.

[1]  Robert L. Jaffe,et al.  Pathways for solar photovoltaics , 2015 .

[2]  Adria E. Brooks,et al.  The consequence of soiling on PV system performance in Arizona; Comparing three study methods , 2013, 2013 IEEE 39th Photovoltaic Specialists Conference (PVSC).

[3]  D. Pysch,et al.  Analysis of the Temperature Dependence of the Open-Circuit Voltage , 2012 .

[4]  Abdérafi Charki,et al.  The Time-Variant Degradation of a Photovoltaic System , 2013 .

[5]  Dirk C. Jordan,et al.  Photovoltaic Degradation Rates—an Analytical Review , 2012 .

[6]  A. E. Brooks,et al.  I–V curves and visual inspection of 250 PV modules deployed over 2 years in tucson , 2012, 2012 38th IEEE Photovoltaic Specialists Conference.

[7]  J. Coello.  Degradation of Crystalline Silicon Modules: A Case Study on 785 Samples After Two Years under Operation , 2011 .

[8]  G. R. Mon,et al.  Test techniques for voltage/humidity-induced degradation of thin-film photovoltaic modules , 1990 .

[9]  T. J. McMahon.  Accelerated testing and failure of thin‐film PV modules , 2004 .

[10]  Andrea Reale,et al.  Acceleration factor for ageing measurement of dye solar cells , 2013, Microelectron. Reliab..

[11]  Martin A. Green,et al.  Silicon photovoltaic modules: a brief history of the first 50 years , 2005 .

[12]  Sarah Kurtz,et al.  Photovoltaic-reliability R&D toward a solar-powered world , 2009, Optics + Photonics for Sustainable Energy.

[13]  Abdérafi Charki,et al.  Lifetime Estimation of a Photovoltaic Module Subjected to Corrosion Due to Damp Heat Testing , 2013 .

[14]  Adria Brooks,et al.  Performance reviews from the Tucson Electric Power solar test yard , 2011, 2011 37th IEEE Photovoltaic Specialists Conference.

[15]  T. J. McMahon,et al.  History of accelerated and qualification testing of terrestrial photovoltaic modules: A literature review , 2009 .

[16]  E. Skoplaki,et al.  ON THE TEMPERATURE DEPENDENCE OF PHOTOVOLTAIC MODULE ELECTRICAL PERFORMANCE: A REVIEW OF EFFICIENCY/ POWER CORRELATIONS , 2009 .

[17]  Olivier Haillant,et al.  Accelerated weathering testing principles to estimate the service life of organic PV modules , 2011 .

[18]  Daryl R. Myers,et al.  Recent Progress in Reducing the Uncertainty in and Improving Pyranometer Calibrations , 2001 .

[19]  K. Otani,et al.  Long‐term performance degradation of various kinds of photovoltaic modules under moderate climatic conditions , 2011 .

[20]  Asterios Bakolas,et al.  Assessment of the Performance and Defect Investigation of PV Modules after Accelerated Ageing Tests , 2013 .

[21]  Dirk C. Jordan,et al.  Technology and Climate Trends in PV Module Degradation: Preprint , 2012 .

[22]  Dimitrios Hariskos,et al.  Accelerated Aging and Contact Degradation of CIGS Solar Cells , 2012, IEEE Journal of Photovoltaics.

[23]  E. Cuddihy.  The aging correlation (RH + t): relative humidity (%) + temperature (°C) , 1987 .

[24]  Jim Pruett,et al.  Qualification testing of thin-film and crystalline photovoltaic modules , 1994, Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC).

[25]  S. Kurtz,et al.  Outdoor PV degradation comparison , 2010, 2010 35th IEEE Photovoltaic Specialists Conference.

[26]  K. Simmons-Potter,et al.  Comparison of environmental degradation in Hanwha 295 W and SunPower 320 W photovoltaic modules via accelerated lifecycle testing , 2014, Optics & Photonics - Solar Energy + Applications.

[27]  Jae-Seong Jeong,et al.  Field failure mechanism study of solder interconnection for crystalline silicon photovoltaic module , 2012, Microelectron. Reliab..