3 DuPont-Summer Xia

DuPont PV Module Reliability Program: Learnings from Field Studies of Solar Panels Summer Xia, Hongjie Hu, Roy Choudhury Kaushik DuPont PV Reliability DuPont Photovoltaic and Advanced Materials SNEC2019, Shanghai, China DowDuPont Copyright 2018, All rights reserved. Will PV modules perform for 30+ years? 2 ▪ Industry focused on nominal degradation rates and initial capital expenses (CAPEX) as key metrics ▪ Unanticipated Operational Expense (OPEX) can have greater financial impact than degradation rates • Studies have shown modules having performance issues related to field ▪ Reluctance to acknowledge, learn from and act upon field failures Expectation: All PV modules need to meet claims for degradation and performance over lifetime ▪ “design & build” to “operate & maintain” – Improved understanding of system performance as a result of OPEX is required to obtain reliable economic assessments – Understanding of durability issues through field analysis will lead to more accurate LCOE models and deeper understanding of system economics 6/17/2019DowDuPont Copyright 2018, All rights reserved. DuPont global field reliability program A highly developed field inspection and analysis program that tracks material degradation and effects on module performance. Inspections cover PV modules of different ages, with many different Bill of Materials (BoM), from different climates, different mounting configurations, and sites in North America, Europe, Asia and the Middle East. • Statistical analysis of 1.8 GW of field data, components, material, age, failure mode • Extensive post-inspection analytical characterization of select modules of variable BoM • Collaboration with field partners, customers, downstream developers, government laboratories and universities 6.5 M modules 355 Installations 1.8 GW modules 6/17/2019DowDuPont Copyright 2018, All rights reserved. 2019 Global field data analysis summary ▪ Nearly 2 GW of fields inspected • Total module defects observed: 34% • Total backsheet defects observed: 14% • Backsheet defects increased by 47% from 2018 analysis • Cracking constitutes 66% of all backsheet defects Cell / Interconnect: corrosion, hot spot, snail trails, broken interconnect, cracks, burn marks Backsheet: outer layer (air side) and inner layer (cell side) cracking, delamination, yellowing Encapsulant: discoloration, browning, delamination Other: glass defects, loss of AR coating, junction box * Actual module defects can be higher due to defects not picked up by initial inspection protocol (eg. cell cracking evidenced by subsequent EL or PID test) 4 Module Defect Trends* No Defects (68%) Backsheet (14%) Cell / Interconnect (14%) Encapsulant (5%) Other (10 Years Downstream Owner($175 Million / Year) RISK Example 6/17/2019DowDuPont Copyright 2018, All rights reserved. Copyright © 2019 DuPont. All rights reserved. DuPont™ and the DuPont Oval Logo are trademarks or registered trademarks of DuPont or its affiliates. Nothing contained herein shall be construed as a representation that any recommendations, use or resale of the product or process described herein is permitted and complies with the rules or regulations of any countries, regions, localities, etc., or does not infringe upon patents or other intellectual property rights of third parties. The information provided herein is based on data DuPont believes to be reliable, to the best of its knowledge and is provided at the request of and without charge to our customers. Accordingly, DuPont does not guarantee or warrant such information and assumes no liability for its use. If this product literature is translated, the original English version will control and DuPont hereby disclaims responsibility for any errors caused by translation. This document is subject to change without further notice. Thank You