• Comprehensive study of performance degradation of field‐mounted photovoltaic modules in India [Energy Science & Engineering, 2017, DOI: 10.1002/ese3.150 ]

[Quote] … Modules falling in the ‘not‐so‐good’ category (Group Y) show even higher degradation rates, and it is at least partly due to higher number of micro‐cracks in the modules, and increased degradation of the packaging materials like encapsulant, backsheet, etc. Modules in ‘Hot’ climates degrade faster than modules in the ‘Non‐Hot’ climates…. [Unquote]

• Performance of Field-Aged PV Modules in India: Results from 2016 All India Survey of PV Module Reliability [2017 IEEE 44th Photovoltaic Specialist Conference (PVSC), DOI: 10.1109/PVSC.2017.8366143]

[Quote]… The modules in `Hot’ climates degrade faster than modules in `Non-Hot’ climates, consistent with earlier results. Modules in small systems (capacity <100 kW) degrade at a faster rate than those in large systems (capacity >100 kW). Roof-mounted systems also degrade at a faster rate than ground-mounted systems…. [Unquote]

• All india survey of photovoltaic module degradation 2014: Survey methodology and statistics [2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), DOI: 10.1109/PVSC.2015.7355712]

[Quote] …  A total of 1080 modules belonging to different photovoltaic technologies were inspected from 45 different sites which are spread across the 5 different climatic zones of India. This is the first survey in India in which electroluminescence, illuminated and dark I-V measurements, insulation resistance and various other tests were carried out on PV modules installed in the field. …. [Unquote]

• Visual degradation in field-aged crystalline silicon PV modules in India and correlation with electrical degradation [IEEE Journal of Photovoltaics, 2014, DOI: 10.1109/JPHOTOV.2014.2356717 ]

[Quote] … The modules installed in the Cold climate suffered lower degradation than modules in hotter climates. Both discoloration and corrosion have been seen in modules across all age groups, even in some of the modules installed less than five years ago. …. [Unquote]

On-site electroluminescence study of field-aged PV modules [2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC), DOI: 10.1109/PVSC.2018.8548080]

[Quote] …Cracks have been detected in most of the PV modules which show poor performance. The percentage of cracked cells is higher in young (age<; =5 years) modules as compared to the old (age > 5 years) modules, and also in modules rack-mounted on the roof compared to those mounted on the ground. The power degradation rate was found to increase with increase in the number of cracks in the PV module. Cracks were found to cause fill factor degradation in the modules which is responsible for the power degradation… [Unquote]

Correlating infrared thermography with electrical degradation of PV modules inspected in all-India survey of photovoltaic module reliability 2016 [IEEE Journal of Photovoltaics, 2018, DOI: 10.1109/JPHOTOV.2018.2859780]

[Quote] …Modules with high thermal mismatch (hot cells) under MPPT condition show high power degradation, caused mainly due to fill factor degradation… The analysis indicates that modules having cracks and hot cells have higher power degradation than modules having cracks but no hot cells. This indicates that the worst cracks tend to create hot cells in the modules, while the benign cracks (which have lesser impact on power output) do not affect the cell temperature to that extent… [Unquote]

Quantification of PV Module Discoloration Using Visual Image Analysis [2017 IEEE 44th Photovoltaic Specialist Conference (PVSC), DOI: 10.1109/PVSC.2017.8366593]

[Quote]…  We hereby describe techniques for analyzing visual images to quantify the discoloration, with the ultimate aim of estimating the short circuit current degradation. Our analysis shows that it is possible to estimate the Yellowness Index of discolored areas in PV modules from the visual images, and it correlates well with the reduction in short circuit current density (calculated from quantum efficiency measurements)…. [Unquote]