Energetica India Magazine nº88 March-April 2020

Mr. Rajaram Pai Business Leader - South Asia & ASEAN, DuPont Photovoltaic Solutions. “Many plants across the globe are still newbut they have PV modules with backsheet materials that have shown premature degradation between 5 – 8 years and are highly likely to show backsheet failures over the next few years”. E nergetica I ndia : What kind of insights do we have from DuPont’s annual Global Field Reliability Study from the Indian perspective? R ajaram P ai : DuPont has been collect- ing data on material degradation for al- most a decade through field inspections across the world to see how panels per - form in various climates. As per 2019 Du - Pont global field studies, out of 0.7 GW panels inspected in India, approximately 11% panels exhibited backsheet de - fects. The backsheet defect rate went up to ~35% in 4+ year old installations. For backsheet materials, defect rate in poly - ethylene terephthalate (PET), polyamide (PA), polyvinylidene fluoride (PVDF) and coating based backsheets was found to be in the range of 14-70% in 4+ years old plants (most of these plants were less than 10 years). The findings suggest the following con - clusions which are relevant for Indian installations: • Backsheet failures are typically ob - served after 4-7 years of field exposure. Failure rate and defect severity increase as the modules age. • Quality of backsheets depends on their materials. While no backsheets fail - ures were observed in Tedlar® polyvinyl fluoride (PVF) based backsheets, defect rates increased substantially (in last 5 years) as manufacturers started using new, but unproven, materials (over last 10 years). • Many plants across the globe are still Energetica India catches up with Mr. Rajaram Pai, Business Leader - South Asia & ASEAN, Du- Pont Photovoltaic Solutions to discuss the importance of backsheets in solar modules. 20 energetica INDIA- March-April_2020 INTERVIEW