PV Module: Best Practices for Risk MitigationMESIA Solar Energy Trade Mission 27th November, Riyadh

Rahul KhatriTechnical Leader, DuPont Photovoltaic Solutions, South Asia and Middle EastRahul.khatri@dupont.com

DuPont Photovoltaic Solutions

Downstream Engagement

Quality Awareness | Field Module Inspection | Accelerated Testing

2

For over 40 years, our material innovations have led the photovoltaics industry forward.

© 2019 DuPont

© 2019 DuPont

Solar Blessed KSA has Tremendous Potential to Produce Solar Energy

Top 5 countries based on installed solar capacity

3

© 2019 DuPont

However, Harsh KSA Climate Brings its own set of Challenges

High UV

High TemperatureSource: eldoradoweather.com

Strong Sand Storms

Source: sinovoltaics.com

High UV

Source: KNMI

4

© 2019 DuPont

Environmental Stresses Can Negatively Impact Module’s Performance

Risk

ImpactPower Loss (negative temp.

coefficient)

Faster Material Degradation

Power Loss(dust shadowing)

High UV Sand StormsHigh Temperature

Stress

5

DuPont Global Field Reliability Program

6.5 Million Modules

355 Installations

1.8 GW Capacity

<5 years Average Age

Visual Defect Rate in Materials

High Defect Rates in Cells and Backsheets

6© 2019 DuPont

High Temperature, UV, and Dust Accelerates Degradation of Materials that are Exposed to the Environment

7

Impact of Temperature Impact of UV Impact of Sand

Cracking of Polyamide (PA) backsheet after 7 years370 MWhr/year power loss

Cracking of PET backsheet after 4-5 years

Abrasion of PET backsheetafter 9 years

Impact of backsheet failure on plant’s performance

• Generation loss: Ground faults, inverter tripping, moisture ingress

• Safety hazard: Current leakage, arcing, burning

PET - Polyethylene terephthalate

© 2019 DuPont

Case Study: Performance of Modules with Different Materials in Climate Similar to KSA

• 12 MW Ground Mount, 7 years old, Arizona

• Tier 1 Module Supplier

• Backsheet Materials – PVDF, PA, PET, PVF

Findings:

• 100% PVDF backsheet cracked

• 100% PA backsheet cracked

• 100% PET backsheet cracked

• No defects in PVF backsheets

PVDF – Cracked in all modules

PA – Cracked in all modules PVF – No defects

8

PVDF – PolyVinylidene fluoride; PA – Polyamide, PET - Polyethylene terephthalate, PVF – PolyVinyl Fluoride

© 2019 DuPont

Case Study: Continued….

9

• All Modules replaced. However….

• Replacement process took months that escalated labor cost and income loss from interruption of power generation

Note: Replacement under warranty depends on terms and conditions. Backsheet cracking is typically covered by manufacturing warranty. If manufacturing warranty is of 10 years, backsheet cracking reported after 10 years will not be considered for free replacement

© 2019 DuPont

Learnings Modules with different materials would perform differently Poor material will fail in harsh climates Backsheet failure requires module replacement and thus is quite serious High financial loses for module supplier Financial loses for plant owner as well, which could escalate if module manufacturer

doesn’t replace modules

Selection of Right Module is Important to Mitigate Performance Risks in KSA Climate

10

Module Technology

• Half-cut Mono-PERC Crystalline Silicon

• BifacialHigh albedo (~40%*) from sand covered ground make bifacial attractive for KSA

Module Materials

• Specify and use field proven materials such as Tedlar® PVF Backsheets, which has >30 years of proven field performance in all types of climates

*source: Tetzlaff, G. (1983). Albedo of the Sahara. Cologne University Satellite Measurement of Radiation Budget Parameters. pp. 60–63.

Lesser Resistive Losses

Low temp. coefficient Better performance in high temperatures

© 2019 DuPont

Clear Tedlar® PVF Backsheets for Bifacial Modules

11

No defects after 20 years

Benefits over Double Glass

• High solar transmission of >91%

• Proven field performance

• Less prone to cracking and delamination

• Lower weight enables lower BoS and installation cost

• Easier rear side cleaning

© 2019 DuPont

Summary

• Harsh KSA climate poses challenging conditions for PV modules• High temperature, high UV, and dust accelerates degradation of module

materials

• Modules performance, reliability and safety depends on its materials and construction

• Poor materials are failing quickly in harsh climatic conditions and resulting in faster power loss and safety hazards

• Risk Mitigation: Specify Bill of Materials and Ensure Use of Field Proven Materials

• Apple to apple comparison of modules from different suppliers• Mitigate module failure risks and protect investment

12© 2019 DuPont

DuPont is Forging Collaborations with Key Stakeholders in KSA

13

KAUST and Desert Technologies

• Performance analysis of modules in KSA

• Field inspections in KSA

Open to Collaborations with all stakeholders for…

• Material supply for modules

• Bill of material specifications

• Field inspections (IPPs, Field Owners, Technical Institutes)

• Quality awareness, share learning from other regions

• Codes and Standards development

• New product development

© 2019 DuPont

Thank You

Copyright © 2019 DuPont. All rights reserved. DuPont™, the DuPont Oval Logo and all trademarks and service marks denoted with ™, ℠ or ® are owned by affiliates of DuPont de Nemours, Inc. unless otherwise noted.

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.

THE BITTERNESS OF POOR QUALITY REMAINS LONG AFTER THE SWEETNESS OF LOW PRICE IS FORGOTTEN